JP2023039584A - Substrate processing method and substrate processing device - Google Patents

Abstract

[Problem] To provide a technology for improving the stripping ability of resist. [Solution] The substrate processing method includes a holding step (step S1) of holding a substrate W provided with resist on a holder 1, a first plasma processing step (step S2) of irradiating the substrate W held on the holder 1 with plasma, a liquid film forming step (step S3) of forming a liquid film of a processing liquid on the substrate W held on the holder 1 after the first plasma processing step, a second plasma processing step (step S5) of irradiating the substrate W held on the holder 1 with plasma after the liquid film forming step, and a rinsing step (step S6) of washing away the liquid film from the substrate W held on the holder 1 after the second plasma processing step. [Selected Figure] Figure 3

Description

The present application relates to a substrate processing method and a substrate processing apparatus.

2. Description of the Related Art In a manufacturing process of a semiconductor device, a resist is sometimes provided as a mask in order to selectively perform etching, ion implantation, or the like on the main surface of a substrate. After etching and ion implantation are performed, the resist is no longer needed, so a process of stripping (removing) the resist is performed. Various methods have been proposed for stripping the resist provided on the substrate (for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2020-88208

As one method for stripping the resist provided on the substrate, a method of forming a liquid film of a processing liquid containing sulfuric acid on the substrate and irradiating the liquid film with plasma is considered. In this method, active species contained in the plasma react with sulfuric acid to generate Caro's acid (peroxomonosulfuric acid: H ₂ SO ₅ ), which oxidizes the resist, thereby stripping the resist.

The oxidizing power of Caro's acid is extremely high, and the above technique achieves a sufficiently high stripping ability. However, when the resist film is particularly thick, when the amount of ion implantation is particularly large, when it contains incompatible polymers, etc., it takes time for the resist to be sufficiently stripped, or sulfuric acid is used. It is possible that the amount used may increase. Therefore, there has been a demand for a technique for further improving the resist stripping ability.

The present application has been made in view of such problems, and its object is to provide a technique for improving the peeling ability of the resist.

A first aspect is a substrate processing method, comprising a holding step of holding a substrate provided with a resist in a holding portion, and a first plasma processing step of irradiating the substrate held in the holding portion with plasma. and, after the first plasma processing step is performed, a liquid film forming step of forming a liquid film of the processing liquid on the substrate held in the holding portion; and after the liquid film forming step is performed, the a second plasma processing step of irradiating the substrate held by the holding portion with plasma; and a rinsing step of washing away the liquid film from the substrate held by the holding portion after the second plasma processing step is performed; Prepare.

A second aspect is the substrate processing method according to the first aspect, comprising a film thickness measuring step of measuring the thickness of the liquid film formed in the liquid film forming step.

A third aspect is the substrate processing method according to the second aspect, wherein the processing conditions of the second plasma processing step are adjusted based on the measured value obtained in the film thickness measuring step.

A fourth aspect is the substrate processing method according to any one of the first to third aspects, wherein a gas that promotes generation of plasma is supplied in the first plasma processing step.

A fifth aspect is the substrate processing method according to any one of the first to fourth aspects, wherein the second plasma processing step is performed in a state in which the supply of the gas promoting plasma generation is stopped.

A sixth aspect is the substrate processing method according to any one of the first to fourth aspects, wherein a gas that promotes generation of plasma is supplied in the second plasma processing step.

A seventh aspect is the substrate processing method according to any one of the first to sixth aspects, wherein, in the first plasma processing step, plasma is arranged opposite to the main surface of the substrate held by the holding part. While irradiating the substrate with plasma from the irradiation unit, the substrate is rotated at a predetermined rotation speed around a rotation axis perpendicular to the main surface, and the predetermined rotation speed is 5 (rpm). above and below 20 (rpm).

An eighth aspect is the substrate processing method according to any one of the first to seventh aspects, wherein in the second plasma treatment step, the plasma is arranged to face the main surface of the substrate held by the holding part. While irradiating the substrate with plasma from the irradiation unit, the substrate is not rotated around the rotation axis orthogonal to the main surface, or is rotated at a rotation speed of 30 (rpm) or less.

A ninth aspect is the substrate processing method according to any one of the first to eighth aspects, wherein in the first plasma processing step, a first plasma is formed between the main surface of the substrate held by the holding part and the first plasma. Plasma is applied to the substrate from the plasma irradiation units that are arranged facing each other while providing a separation distance. Plasma is applied to the substrate from the plasma irradiating units facing each other while providing a second separation distance smaller than the separation distance.

A tenth aspect is a substrate processing apparatus comprising: a holding section for holding a substrate; a plasma irradiation section for irradiating the substrate held by the holding section with plasma; and a control unit for irradiating the substrate held by the holding unit with plasma from the plasma irradiation unit, wherein the The control unit causes the substrate before the liquid film is formed to be irradiated with plasma, and further causes the substrate after the liquid film is formed to be irradiated with plasma.

According to the substrate processing method of the first aspect, the substrate is irradiated with plasma before and after the liquid film of the processing liquid is formed. In the plasma irradiation of the substrate before the liquid film of the processing liquid is formed (first plasma processing step), the plasma directly acts on the resist to decompose the polymer contained in the resist (reduce the molecular weight). etc. progresses, and the resist is changed into a film that is easily peeled off. On the other hand, in the irradiation of the plasma to the substrate after the liquid film of the processing liquid is formed (second plasma processing step), the processing capability of the processing liquid is enhanced by the action of the plasma on the processing liquid, and the resist due to the processing liquid is increased. detachment progresses. In other words, in this substrate processing method, the processing liquid whose processing capability is enhanced by the plasma irradiation in the second plasma processing step after the film quality of the resist is changed into a state in which it is easy to peel off by the plasma irradiation in the first plasma processing step. , the resist is stripped. Therefore, even if the resist is relatively difficult to peel off, it can be peeled off without difficulty. That is, the ability to remove the resist can be improved.

According to the substrate processing method of the second aspect, the thickness of the liquid film formed in the liquid film forming step is measured. In the liquid film forming process, even if the processing conditions are set to be the same, the thickness of the actually formed liquid film may vary slightly between substrates. Furthermore, it is considered that this variation is particularly likely to occur when the substrate before the liquid film is formed is irradiated with plasma and the film quality of the resist is degraded. If there is variation in the thickness of the liquid film among substrates, the progress rate of the plasma processing in the second plasma processing step will vary, and there is a risk that the uniformity of processing will not be ensured among the substrates. By being measured, it is possible to perceive situations in which such variations may occur.

According to the substrate processing method of the third aspect, the processing conditions for the second plasma processing step are adjusted based on the measured value obtained in the film thickness measuring step. Therefore, even if the thickness of the liquid film varies between substrates, by adjusting the processing conditions of the second plasma processing step so as to offset this variation, it is possible to avoid variations in processing between substrates. .

According to the substrate processing method according to the fourth aspect, in the first plasma processing step, the gas that promotes the generation of plasma is supplied, so the plasma processing can proceed effectively.

According to the substrate processing method according to the fifth aspect, since the second plasma processing step is performed with the gas supply stopped, the liquid film formed on the substrate is shaken or swept away by the gas flow. There is no such thing as Therefore, the uniformity of processing within the plane of the substrate is sufficiently ensured.

According to the substrate processing method according to the sixth aspect, in the second plasma processing step, the gas that promotes the generation of plasma is supplied, so the plasma processing can proceed effectively.

According to the substrate processing method of the seventh aspect, in the first plasma processing step, the substrate is rotated at a rotation speed of 5 (rpm) or more and 20 (rpm) or less. Even if the distribution of the active species in the plasma is non-uniform, the rotation of the substrate allows the active species to act evenly over the entire main surface of the substrate. The uniformity of processing within can be enhanced. On the other hand, if the number of revolutions when the substrate is rotated is too high, it will cause turbulence in the airflow and cause an imbalance in the distribution of active species in the plasma (that is, the uniformity of the processing within the surface of the substrate will be reduced). However, by setting the rotational speed to 20 (rpm) or less, such a situation can be avoided.

According to the substrate processing method according to the eighth aspect, in the second plasma processing step, the substrate is not rotated, or is rotated at a rotation speed of 30 (rpm) or less, so that the liquid film formed on the substrate is Shaking and biasing can be suppressed. Therefore, the uniformity of processing within the plane of the substrate is sufficiently ensured.

In the substrate processing method according to the ninth aspect, the separation distance between the substrate and the plasma irradiation section is different between the first plasma processing step and the second plasma processing step. The smaller the separation distance, the more the plasma processing is promoted. Here, when a liquid film is formed on the substrate, discharge is less likely to occur than when the liquid film is not formed. That is, the minimum separation distance that must be ensured to avoid discharge is smaller when the liquid film is formed on the substrate than when the liquid film is not formed. In the substrate processing method according to this aspect, the distance between the substrate and the plasma irradiation section in the second plasma processing step is smaller than the distance between the substrate and the plasma irradiation section in the first plasma processing step, In each of the first and second plasma processing steps, it is possible to sufficiently promote the plasma processing while suppressing the occurrence of electrical discharge.

According to the substrate processing apparatus according to the tenth aspect, the substrate before the liquid film of the processing liquid is formed is irradiated with the plasma, and the substrate after the liquid film is formed is also irradiated with the plasma. be done. By the former plasma irradiation, the film quality of the resist is changed into a state that is easy to peel off, and then the resist is stripped by the processing liquid whose processing ability has been enhanced by the latter plasma irradiation, so that the resist is relatively stripped. Even in difficult cases, it can be peeled off without difficulty. That is, the ability to remove the resist can be improved. Further, here, since the former and the latter plasma irradiation are performed by the same apparatus, for example, the substrate before the liquid film of the processing liquid is formed is irradiated with the plasma by the first apparatus, and the substrate is exposed to the plasma. Compared to a configuration in which the substrate is transferred from the first device to the second device, and the second device irradiates the substrate on which the liquid film has been formed, the processing time is greatly shortened. be done.

It is a top view which shows the structure of a substrate processing system typically. 3 is a block diagram showing the configuration of a control unit; FIG. 4 is a side view schematically showing the configuration of the processing unit; FIG. 1 is a plan view schematically showing the configuration of a plasma reactor; FIG. It is a figure which shows the flow of the process performed in a processing unit. It is a figure for demonstrating a holding process. It is a figure for demonstrating a 1st plasma processing process. It is a figure for demonstrating a liquid film formation process. It is a figure for demonstrating a film-thickness measurement process. It is a figure for demonstrating a 2nd plasma processing process. It is a figure for demonstrating a rinse process. FIG. 4 is a diagram for explaining a manner in which the discharge flow rate of gas is switched according to the height of the plasma reactor; It is a figure which shows the flow of a process when a repetition process is performed.

Embodiments will be described below with reference to the accompanying drawings. Note that the components described in this embodiment are merely examples, and the scope of the present disclosure is not intended to be limited to them. Also, in the drawings, for ease of understanding, the dimensions or number of each part may be exaggerated or simplified as necessary.

Expressions that indicate relative or absolute positional relationships (e.g., "in one direction", "along one direction", "parallel", "perpendicular", "center", "concentric", "coaxial", etc.) Unless otherwise specified, not only expresses the positional relationship strictly, but also expresses the state of being displaced in terms of relative angle or distance within the range of tolerance or equivalent function. In addition, unless otherwise specified, expressions indicating equality (e.g., “identical”, “equal”, “homogeneous”, etc.) not only express quantitatively exact equality, but also It shall also represent the state in which there is a difference in which the degree of function is obtained. In addition, expressions indicating shapes (e.g., “circular”, “square”, “cylindrical”, etc.), unless otherwise specified, not only express the shape strictly geometrically, but also The shape represents a range in which an effect can be obtained, and may have, for example, unevenness or chamfering. In addition, each expression such as "comprising", "comprising", "having", "including", or "having" a component is not an exclusive expression excluding the existence of other components. In addition, the expression "at least one of A, B and C" includes "only A", "only B", "only C", "any two of A, B and C", " All of A, B and C" are included.

<1. Overall Configuration of Substrate Processing System>
A configuration of the substrate processing system 100 will be described with reference to FIG. FIG. 1 is a plan view schematically showing the configuration of a substrate processing system 100. FIG.

The substrate processing system 100 is a processing system that performs predetermined processing on a substrate W to be processed, and includes an interface section 110 , an indexer section 120 , a main body section 130 and a control section 140 . A substrate W to be processed in the substrate processing system 100 is, for example, a semiconductor substrate. The shape of the substrate W to be processed is, for example, a disc shape, and its size (diameter) is, for example, about 300 (mm).

The interface unit 110 is an interface for connecting the carrier C, which is a substrate container that accommodates a plurality of substrates W, to the substrate processing system 100. Specifically, for example, a load port on which the carrier C is placed. 111 are arranged in a row in the horizontal direction (three in the example shown). The carrier C may be of a type that accommodates the substrates W in an enclosed space (for example, a FOUP (Front Opening Unified Pod), a SMIF (Standard Mechanical Interface) pod, etc.), or may expose the substrates W to the outside air. type (for example, OC (Open Cassette), etc.).

The indexer section 120 is a section arranged between the interface section 110 and the main body section 130 and includes an indexer robot 121 .

The indexer robot 121 is a transport robot that transports the substrate W between the carrier C placed on each load port 111 and a main transport robot 131 (described later). It is composed of a connected arm 121b, a drive unit for extending and retracting, rotating, and raising and lowering the arm 121b. The indexer robot 121 accesses the carrier C placed on each load port 111, performs an unloading operation (that is, an operation of taking out the unprocessed substrates W stored in the carrier C with the hand 121a) and a loading operation. An operation (that is, an operation of loading the processed substrate W held by the hand 121a into the carrier C) is performed. The indexer robot 121 also accesses the transfer position T with the main transport robot 131 and transfers the substrate W with the main transport robot 131 .

The body section 130 includes a main transport robot 131 and a plurality of (for example, 12) processing units 132 . Here, for example, a plurality of (for example, three) processing units 132 stacked in the vertical direction constitute one tower, and the tower surrounds the main transfer robot 131 so that a plurality of processing units 132 (eg, four) are provided.

The main transport robot 131 is a transport robot that transports the substrate W between the indexer robot 121 and each processing unit 132. It includes a drive unit for turning and raising and lowering, and the like. The main transport robot 131 accesses each processing unit 132 to perform a loading operation (that is, an operation of loading the substrate W to be processed held by the hand 131a into the processing unit 132) and an unloading operation (that is, processing (operation of taking out the processed substrate W stored in the unit 132 with the hand 131a). Further, the main transport robot 131 accesses the transfer position T with the indexer robot 121 and transfers the substrate W with the indexer robot 121 .

The processing unit 132 is a device that performs a predetermined processing on the substrate W. As shown in FIG. A specific configuration of the processing unit 132 will be described later.

The control unit 140 is an element that controls the operation of each unit included in the substrate processing system 100, and is configured by, for example, a general computer having an electric circuit. Specifically, for example, as shown in FIG. 2, the control unit 140 includes a CPU (Central Processor Unit) 141 as a central processing unit responsible for data processing, and a ROM (Read Only Memory) 142 in which basic programs and the like are stored. , a RAM (random access memory) 143 used as a work area when the CPU 141 performs predetermined processing (data processing), a storage device 144 configured by a non-volatile storage device such as a flash memory, a hard disk device, etc. and a bus line 145 connected to the . The storage device 144 stores a program P that defines the processing to be executed by the control unit 140. When the CPU 141 executes the program P, the control unit 140 executes the processing defined by the program P. can be done. However, part or all of the processing executed by control unit 140 may be executed by hardware such as a dedicated logic circuit.

The control unit 140 may be configured such that a main control unit that controls the overall operation of the substrate processing system 100 and a plurality of local control units are communicably connected. In this case, each of the plurality of processing units 132 is associated with at least one local control section, and the local control section controls the operation of the corresponding processing unit 132 based on instructions from the main control section. It may be controlled. Further, when such a configuration is adopted, each of the main control section and each of the local control sections may individually include part or all of the above sections 141-145.

<2. Processing unit>
Next, the configuration of the processing unit 132 will be described with reference to FIG. FIG. 3 is a side view schematically showing the configuration of the processing unit 132. As shown in FIG. As described above, the main body 130 is provided with a plurality of processing units 132. If at least one of the plurality of processing units 132 has the configuration described below, good. That is, the plurality of processing units 132 may include those having a configuration different from the configuration described below.

The processing unit 132 is, for example, a processing apparatus that performs a process of stripping (removing) a resist provided on the substrate W, and corresponds to a substrate processing apparatus. The processing unit 132 is a so-called single wafer processing apparatus that processes substrates W to be processed one by one.

The processing unit 132 includes a holding section 1 , a liquid supply section 2 , a film thickness measurement section 3 , a plasma generation section 4 , a cutoff section 5 , a gas supply section 6 and a guard section 7 . In addition, the processing unit 132 includes at least some of the elements provided in these parts 1 to 7 (for example, the base part 11, the nozzles 21 and 22, the film thickness sensor 31, the plasma reactor 41, the blocking plate 51, the gas nozzle 61, the guard 71, etc.). A clean air downflow is also preferably formed in the interior space of the chamber 8 by a fan filter unit 81 or the like.

(Holding portion 1)
The holding unit 1 is an element that holds the substrate W to be processed, and includes, for example, a base unit 11 , a plurality of chuck pins 12 , and a rotation mechanism 13 .

The base portion 11 is a disc-shaped member having a diameter slightly larger than that of the substrate W, and is arranged in such a posture that the thickness direction thereof extends along the vertical direction. A plurality of chuck pins 12 are provided on the upper surface of the base portion 11 and arranged at intervals along the periphery of the upper surface. Each chuck pin 12 is configured to be displaced between a chuck position in contact with the peripheral edge of the substrate W and a released position away from the peripheral edge of the substrate W according to an instruction from the control unit 140. By arranging the pins 12 at the chuck position, the substrate W is held above the base portion 11 in a horizontal posture (a posture in which the thickness direction of the substrate W is along the vertical direction).

The rotation mechanism 13 is a mechanism for rotating the base portion 11 . Specifically, the rotation mechanism 13 includes, for example, a shaft 13a connected at its upper end to the lower surface of the base portion 11, and a motor 13b connected to the lower end of the shaft 13a. Here, for example, an axis perpendicular to the main surface of the substrate W held on the base portion 11 and passing through the center of the main surface is defined as the rotation axis Q, and the shaft 13a rotates along this axis. It is provided coaxially with the axis Q. Then, the motor 13b rotates the shaft 13a around the rotation axis Q at the number of revolutions instructed by the control unit 140 in accordance with the instruction from the control unit 140 . As the shaft 13a is rotated by being driven by the motor 13b, the base portion 11 and, by extension, the substrate W held on the base portion 11 rotates around the rotation axis Q. As shown in FIG. Thus, the holding unit 1 including the rotation mechanism 13 (that is, the holding unit 1 capable of holding and rotating the substrate W) is also called a spin chuck or the like. Also, the base portion 11 in the spin chuck is also called a spin base.

(Liquid supply unit 2)
The liquid supply unit 2 is an element that supplies liquid to the substrate W held by the holding unit 1, and includes, for example, a processing liquid nozzle 21, a rinse liquid nozzle 22, and a nozzle moving mechanism .

The processing liquid nozzle 21 is a nozzle that supplies the processing liquid to the substrate W held by the holding unit 1, and is, for example, a straight nozzle having an ejection port 21a formed on one end face. The processing liquid nozzle 21 is connected via a processing liquid supply pipe 211 to a processing liquid supply source 212 that stores a predetermined processing liquid (here, sulfuric acid). A valve 213 and a flow control unit 214 are interposed in the processing liquid supply pipe 211 . The valve 213 is a valve that switches between supplying and stopping the processing liquid through the processing liquid supply pipe 211 and is controlled by the control unit 140 . The flow rate adjusting section 214 is configured by, for example, a mass flow controller, and adjusts the flow rate of the processing liquid flowing through the processing liquid supply pipe 211 under the control of the control section 140 . In such a configuration, when the valve 213 is opened, the processing liquid at a predetermined flow rate adjusted by the flow rate adjusting unit 214 is supplied from the processing liquid supply source 212 to the processing liquid nozzle 21 through the processing liquid supply pipe 211 and discharged. It is discharged from the outlet 21a.

In a state where the processing liquid nozzle 21 is arranged at a nozzle processing position described later, the processing liquid is discharged from the discharge port 21a, whereby the processing liquid is supplied to the substrate W held by the holding unit 1, and the substrate W is discharged. A liquid film of the processing liquid is formed on the surface (FIG. 8). That is, the processing liquid is supplied to the substrate W held in the holding unit 1 by the processing liquid nozzle 21 and the processing liquid supply pipe 211 connected thereto to form a liquid film of the processing liquid on the substrate W. A feed section is configured.

The rinse liquid nozzle 22 is a nozzle that supplies the rinse liquid to the substrate W held by the holding unit 1, and is, for example, a straight nozzle having a discharge port 22a formed on one end face. The rinse liquid nozzle 22 stores a predetermined rinse liquid (eg, deionized water (DIW, H-DIW), pure water, ozone water, carbonated water, isopropyl alcohol, etc.) through a rinse liquid supply pipe 221. It is connected to a rinse liquid supply source 222 . A valve 223 and a flow rate adjusting unit 224 are interposed in the rinse liquid supply pipe 221 . The valve 223 is a valve that switches between supplying and stopping the rinse liquid through the rinse liquid supply pipe 221 and is controlled by the controller 140 . The flow rate adjusting section 224 is configured by, for example, a mass flow controller, and adjusts the flow rate of the rinse liquid flowing through the rinse liquid supply pipe 221 under the control of the control section 140 . In such a configuration, when the valve 223 is opened, the rinse liquid at a predetermined flow rate adjusted by the flow rate adjusting section 224 is supplied from the rinse liquid supply source 222 to the rinse liquid nozzle 22 through the rinse liquid supply pipe 221, and discharged. It is discharged from the outlet 22a.

In a state where the rinse liquid nozzle 22 is arranged at a nozzle processing position described later, the rinse liquid is discharged from the discharge port 22a, thereby supplying the rinse liquid to the substrate W held by the holding unit 1 (see FIG. 11). ). That is, here, the rinse liquid supply section that supplies the rinse liquid to the substrate W held in the holding section 1 is constituted by the rinse liquid nozzle 22 and the rinse liquid supply pipe 221 connected thereto.

The nozzle moving mechanism 23 is a mechanism that moves the processing liquid nozzle 21 and the rinsing liquid nozzle 22 between the nozzle processing position and the nozzle standby position. Here, the "nozzle processing position" means that the liquid discharged from the discharge ports 21a and 22a of the nozzles 21 and 22 is supplied to the upper main surface (upper surface) of the substrate W held by the holding unit 1. More specifically, for example, it is above the main surface and faces the center of the main surface in the vertical direction (FIGS. 8 and 11). On the other hand, the “nozzle standby position” means that the nozzles 21 and 22 are placed in a position where other members (the plasma reactor 41 at the plasma processing position, the hand 131a of the main transfer robot 131 that transfers the substrate W to/from the base portion 11, etc.) ), specifically, for example, the position outside (outward in the radial direction) the peripheral edge of the substrate W held by the holding unit 1 when viewed from above (for example, the position shown in FIG. 6).

Here, the processing liquid nozzle 21 and the rinsing liquid nozzle 22 constitute a nozzle unit U by being connected via a connecting member or the like. Specifically, the nozzle moving mechanism 23 includes, for example, an arm that is connected to the nozzle unit U at the tip and extends substantially horizontally, a support that supports the base end of the arm, and a support that rotates the support around its axis. and a motor that rotates at The motor rotates the column about its axis at the rotation angle instructed by the control unit 140 in accordance with the instruction from the control unit 140 . When the support is rotated by being driven by the motor, the arm rotates, and the nozzle unit U connected to the tip of the arm moves along an arc-shaped locus. The position of the support and the length of the arm are defined so that the nozzle processing position and the nozzle standby position are arranged. In other words, the nozzles 21 and 22 move between their respective nozzle processing positions and nozzle standby positions by moving the nozzle unit U along the arc-shaped trajectory.

(Thickness measurement unit 3)
The film thickness measurement unit 3 is an element that measures the thickness (film thickness) of the liquid film of the processing liquid formed on the substrate W held in the holding unit 1. For example, the film thickness sensor 31 and the sensor A moving mechanism 32 is provided.

The film thickness sensor 31 is a sensor (so-called film thickness meter) that measures the film thickness. Specifically, the film thickness sensor 31 is, for example, a reflection spectroscopic film thickness meter using light interference, and includes a light emitter, a spectrometer, a light receiver, a calculator, and the like. When the film thickness sensor 31 measures the film thickness, first, the light emitter irradiates the main surface of the substrate W on which the liquid film of the processing liquid is formed with light for measurement. Then, part of the irradiated light is reflected by the liquid surface of the liquid film, and the remaining part is reflected by the main surface of the substrate W. As shown in FIG. The interference light resulting from the mutual interference of these two reflected lights is incident on the spectroscope, where it is separated. The light receiver receives the split light and measures the intensity of the light for each wavelength. Then, the calculator calculates the measured value of the film thickness based on the obtained measured value. The calculated measured value is output to the control section 140 .

The sensor moving mechanism 32 is a mechanism for moving the film thickness sensor 31 between the film thickness measurement position and the sensor standby position. Here, the "film thickness measurement position" is a position where the film thickness sensor 31 measures the thickness of the liquid film formed on the upper main surface of the substrate W held by the holding unit 1. Specifically, Specifically, it is a position above the main surface and vertically opposed to a position to be measured which is defined in advance in the plane of the main surface (FIG. 9). On the other hand, the "sensor standby position" means that the film thickness sensor 31 is located in the position where the film thickness sensor 31 is located in another member (the plasma reactor 41 at the plasma processing position, the hand 131a of the main transfer robot 131 that transfers the substrate W to and from the base portion 11, etc.). ), specifically, for example, the position outside (outward in the radial direction) the peripheral edge of the substrate W held by the holding unit 1 when viewed from above (for example, the position shown in FIG. 6).

Here, the nozzle moving mechanism 23 that moves the treatment liquid nozzle 21 and the rinse liquid nozzle 22 functions as a sensor moving mechanism 32 that moves the film thickness sensor 31 . That is, the film thickness sensor 31 is connected to the nozzles 21 and 22 via a connecting member or the like to form a nozzle unit U together with the nozzles 21 and 22, and the nozzle moving mechanism 23 (that is, the sensor moving mechanism 32) The nozzle moving mechanism 23) moves the nozzle unit U along an arc-shaped trajectory, so that the film thickness sensor 31 moves between the film thickness measurement position and the sensor standby position defined on the trajectory. Moving.

(Plasma generator 4)
The plasma generation unit 4 is an element that generates plasma and irradiates the substrate W held by the holding unit 1 with the generated plasma. A mechanism 43 is provided. The plasma generator 4 is capable of generating plasma under atmospheric pressure. However, the "atmospheric pressure" referred to here is, for example, 80(%) or more of the standard atmospheric pressure and 120(%) or less of the standard atmospheric pressure.

The plasma reactor 41 is an irradiating section (plasma irradiating section) that irradiates an object (here, the substrate W held by the holding section 1) with plasma. Specifically, the plasma reactor 41 has, for example, a flat shape, and is positioned above the substrate W held by the holding unit 1 in such a posture that the thickness direction (the Z direction described later) is along the vertical direction. and arranged at a position facing the main surface of the substrate W in the vertical direction. The plasma reactor 41 has, for example, a circular shape in plan view, and has a size comparable to (or larger than) the substrate W to be processed.

The configuration of the plasma reactor 41 will be described more specifically with reference to FIG. 4 in addition to FIG. FIG. 4 is a plan view schematically showing the configuration of the plasma reactor 41. As shown in FIG.

The plasma reactor 41 includes a pair of electrode portions (first electrode portion 411 and second electrode portion 412). The pair of electrode portions 411 and 412 are laminated in the thickness direction with a partition plate 413 formed of a dielectric material (for example, quartz, ceramics, etc.) interposed therebetween. Specifically, the first electrode portion 411 is provided on one side in the thickness direction of the disc-shaped partition plate 413 , and the second electrode portion 412 is provided on the other side. Hereinafter, for convenience of explanation, the direction in which the first electrode portion 411, the partition plate 413, and the second electrode portion 412 are stacked is referred to as the "Z direction." Also, in a plane perpendicular to the Z direction, the chord direction of an arc that defines collective electrodes 411b and 412b, which will be described later, is defined as the "Y direction", and the direction perpendicular to the Z direction and the Y direction is defined as the "X direction".

The first electrode portion 411 includes a plurality of linear electrodes (first linear electrodes) 411a made of an appropriate conductive material (eg, tungsten), and a collective electrode made of an appropriate conductive material (eg, aluminum). It is connected via (first collective electrode) 411b, and has a comb shape as a whole. Each of the first linear electrodes 411a is a rod-shaped electrode arranged in such a manner that the longitudinal direction thereof extends along the X direction. It is arranged while being provided. On the other hand, the first collective electrode 411b is an arcuate plate-shaped electrode in plan view, and ends of the first linear electrodes 411a are connected to the inner peripheral edge side thereof.

As with the first electrode portion 411, the second electrode portion 412 includes a plurality of linear electrodes (second linear electrodes) 412a formed of an appropriate conductive material (eg, tungsten). The electrodes are connected via a collective electrode (second collective electrode) 412b made of aluminum), and have a comb shape as a whole. Each of the second linear electrodes 412a is a rod-shaped electrode that is arranged with the long direction along the X direction. It is arranged while being provided. On the other hand, the second collective electrode 412b is an arcuate plate-shaped electrode in plan view, and the end of each of the second linear electrodes 412a is connected to the inner peripheral edge side thereof.

In both electrode portions 411 and 412, the ends of the collective electrodes 411b and 412b face each other when viewed from the Z direction, the swelling direction of the first collective electrode 411b faces the -X direction, and the swelling direction of the second collective electrode 412b faces the -X direction. They are arranged in a positional relationship facing the +X direction. In this state, the second linear electrodes 412a are arranged between the adjacent first linear electrodes 411a when viewed from the Z direction. That is, when viewed from the Z direction, the first linear electrodes 411a and the second linear electrodes 412a are alternately arranged along the Y direction within a substantially circular region surrounded by both collective electrodes 411b and 412b. .

At least each first linear electrode 411 a and each second linear electrode 412 a are covered with a dielectric tube 414 . The dielectric tube 414 is made of a dielectric material (for example, quartz, ceramics, etc.), and is covered with the dielectric tube 414 to protect the linear electrodes 411a and 412a from the plasma.

The power supply 42 is a plasma power supply for generating plasma and is connected to the plasma reactor 41 . Specifically, one of the pair of wires extending from the power supply 42 is connected to the first electrode portion 411 (specifically, the first collective electrode 411b), and the other is connected to the second electrode portion 412 (specifically, the , to the second collective electrode 412b).

Specifically, the power supply 42 is configured by, for example, a high frequency power supply, and is controlled by the control section 140 . The power supply 42 applies a predetermined voltage (for example, a high frequency voltage of about ten (kV) and several tens (kHz)) between the first electrode portion 411 and the second electrode portion 412 in accordance with an instruction from the control portion 140. ) is applied, an electric field is generated between the first linear electrode 411a and the second linear electrode 412a, and the gas around the first linear electrode 411a and the second linear electrode 412a becomes plasma. (So-called dielectric barrier discharge). That is, plasma is generated (lighted).

Further, the power supply 42 is provided with a switching power supply circuit such as an inverter circuit and a pulse generator. A high frequency voltage is applied. In this case, plasma is generated mainly during the ON period.

The plasma reactor moving mechanism 43 is a mechanism for moving (lifting) the plasma reactor 41 between the plasma processing position and the plasma standby position. Here, the “plasma processing position” is a position where the plasma reactor 41 performs plasma processing on the substrate W held by the holding unit 1 (FIGS. 7 and 10). The plasma processing position will be specifically described later. On the other hand, the "plasma standby position" is a position where the plasma reactor 41 does not perform plasma processing on the substrate W held by the holding unit 1, and at least plasma generated by the plasma reactor 41 is applied to the substrate. This is the position where the distance between the two is large enough to not act on W (eg, FIG. 6).

Specifically, the plasma reactor moving mechanism 43 includes, for example, an elevating plate that is connected to the plasma reactor 41 at its tip and extends substantially horizontally, and a motor. A cam is provided between the motor and the lift plate to convert the rotational motion of the motor into the lift motion of the lift plate. Therefore, when the motor rotates by the rotation angle instructed by the control unit 140 in accordance with the instruction from the control unit 140, the elevator plate (and the plasma reactor 41 connected thereto) rotates according to the rotation angle. Ascend (or descend) by distance. However, the configuration of the plasma reactor moving mechanism 43 is not limited to this, and can be realized by various driving mechanisms that achieve vertical movement. For example, the plasma reactor moving mechanism 43 may include a ball screw mechanism and a motor for applying a driving force thereto, or may include an air cylinder.

(Blocking unit 5)
The shielding part 5 is an element that shields the plasma reactor 41 from its upper space, and includes, for example, a shielding plate 51 .

The blocking plate 51 is a plate-like member, and is positioned such that its thickness direction extends along the vertical direction, and is positioned above the plasma reactor 41 so as to face the upper surface of the plasma reactor 41 in the vertical direction. placed in The blocking plate 51 has, for example, the same shape (here, circular shape) as the plasma reactor 41 in a plan view, and is approximately the same size as the plasma reactor 41 (or slightly larger than the plasma reactor 41). ing.

Here, the blocking plate 51 is connected to the plasma reactor 41 via a connecting member or the like. Therefore, when the plasma reactor moving mechanism 43 raises and lowers the plasma reactor 41 , the blocking plate 51 is raised and lowered integrally with the plasma reactor 41 while maintaining a predetermined positional relationship with the plasma reactor 41 .

(Gas supply unit 6)
The gas supply unit 6 is an element that supplies gas between the substrate W held by the holding unit 1 and the plasma reactor 41, and includes a gas nozzle 61, for example.

The gas nozzle 61 is a nozzle that discharges gas between the substrate W held by the holding unit 1 and the plasma reactor 41. Specifically, for example, the nozzle main body 61a and the nozzle main body 61a are provided with and a discharge port 61b. The nozzle main body 61a is a ring-shaped member that hangs downward from the peripheral edge of the plasma reactor 41 and is provided so as to surround the plasma reactor 41 from the sides. A plurality of discharge ports 61b are provided at equal intervals in the circumferential direction, for example, in a region on the lower end side extending downward from the plasma reactor 41 on the inner peripheral surface of the nozzle body portion 61a.

A gas flow path is provided inside the nozzle main body 61a, and each discharge port 61b communicates with this gas flow path. Also, this gas flow path is connected via a gas supply pipe 611 to a gas supply source 612 that stores a predetermined gas. A valve 613 and a flow control unit 614 are interposed in the gas supply pipe 611 . The valve 613 is a valve that switches between supplying and stopping the gas through the gas supply pipe 611 and is controlled by the controller 140 . The flow rate adjusting section 614 is composed of, for example, a mass flow controller, and adjusts the flow rate of the gas flowing through the gas supply pipe 611 under the control of the control section 140 .

In such a configuration, when the valve 613 is opened, a predetermined flow rate of gas adjusted by the flow rate adjustment section 614 is supplied from the gas supply source 612 through the gas supply pipe 611 to the gas provided inside the nozzle main body section 61a. It is supplied to the flow path and discharged from each discharge port 61b. That is, the gas is discharged toward the space below the lower surface from the discharge port 61b provided slightly below the lower surface of the plasma reactor 41 and outside the peripheral edge of the lower surface. At this time, the gas discharge direction is the radial direction of the lower surface when viewed from above (that is, the direction from the peripheral edge side of the lower surface to the opposite peripheral edge side through the center), and when viewed from the side. The direction is parallel to the bottom surface. As a result, the gas is supplied to the space below the lower surface of the plasma reactor 41 (the space between the lower surface and the substrate W held by the holding unit 1).

Here, the gas nozzle 61 is provided in connection with the plasma reactor 41 . Therefore, when the plasma reactor moving mechanism 43 raises and lowers the plasma reactor 41 , the gas nozzle 61 is raised and lowered integrally with the plasma reactor 41 while being arranged at a predetermined relative position with respect to the plasma reactor 41 .

(Guard part 7)
The guard section 7 is an element that receives the processing liquid that scatters from the substrate W held by the holding section 1, and includes, for example, one or more (here, two) guards 71 and a guard moving mechanism 72. .

The guard 71 includes a tubular portion 71a, an inclined portion 71b, and an extending portion 71c. The tubular portion 71 a is a cylindrical portion and is provided so as to surround the holding portion 1 . The inclined portion 71b is provided so as to continue from the upper edge of the cylindrical portion 71a, and is inclined inward as it goes vertically upward. The extending portion 71c is a plate ring-shaped portion, and is provided so as to extend inward in a substantially horizontal plane from the upper end edge of the inclined portion 71b. Even when a plurality of guards 71 are provided, each guard 71 basically has the same configuration. However, in this case, the sizes of the guards 71 are different from each other, and the guards 71 are arranged in a nested manner. That is, the tubular portion 71a is arranged concentrically, and the inclined portion 71b and the extending portion 71c are arranged in a nested manner so that they are vertically stacked.

The guard moving mechanism 72 is a mechanism that moves (lifts) the guard 71 between the guard processing position and the guard standby position. However, when a plurality of guards 71 are provided, the guard moving mechanism 72 moves each guard 71 independently. Here, the “guard processing position” is a position where the guard 71 receives the processing liquid and the like that scatter from the substrate W held by the holding section 1. Specifically, for example, the extending portion 71c The position is such that it is positioned above the substrate W (eg FIG. 8). On the other hand, the "guard standby position" is a position where the guard 71 does not interfere with other members (such as the hand 131a of the main transport robot 131 that transfers the substrate W to and from the base portion 11). Specifically, for example, the extending portion 71c is positioned below the substrate W held by the holding portion 1 (eg, FIG. 6).

The guard moving mechanism 72 can be realized by various drive mechanisms that realize vertical movement. Specifically, for example, the guard moving mechanism 72 may include a ball screw mechanism, a motor for applying a driving force to the ball screw mechanism, or the like, or may include an air cylinder or the like. As described above, when a plurality of guards 71 are provided, each of the plurality of guards 71 is provided with these drive mechanisms so as to move each guard 71 independently.

Below the guard 71 , a liquid draining portion 73 is provided for draining the processing liquid and the like received on the inner peripheral surface of the guard 71 . Specifically, the drain part 73 includes, for example, a cup 731 provided below the guard 71, a drain pipe 732 connected to the cup 731, and the like. The processing liquid received by the inner peripheral surface and flowing down along the inner peripheral surface is received by the cup 731 and is drained from the drain pipe 732 . Although not shown, when a plurality of guards 71 are provided, individual cups are provided below each guard 71 .

An exhaust portion 74 for exhausting gas, mist, etc. flowing along the inner peripheral surface of the guard 71 is provided on the outer side of the guard 71 . The exhaust part 74 specifically includes, for example, a peripheral wall part 741 provided to surround the guard 71 from the outside, an exhaust pipe 742 connected to the peripheral wall part 741, and the like, and is arranged at the guard processing position. Gas, mist, etc., which is received by the inner peripheral surface of the guard 71 and flows down along the inner peripheral surface, is received by the peripheral wall portion 741 and is exhausted from the exhaust pipe 742 .

<3. Process Flow>
Next, the flow of processing performed by the processing unit 132 will be described with reference to FIGS. 5 and 6 to 11 in addition to FIG. FIG. 5 is a diagram showing the flow of the processing. Each of FIGS. 6 to 11 is a diagram for explaining each processing step, and schematically shows the state of each part in the processing step.

In the following description, the substrate W to be processed is, for example, a substrate W after etching or ion implantation has been performed by providing a resist as a mask on at least one of its principal surfaces. , a series of processes are performed to remove the resist that is no longer needed. A series of processes described below are performed by the control section 140 controlling each section provided in the processing unit 132 .

Step S<b>1 : Holding Step First, the substrate W to be processed is held by the holding section 1 . That is, when the main transfer robot 131 inserts the hand 131a holding the substrate W to be processed into the chamber 8 and loads the substrate W into the processing unit 132, the holding unit 1 moves the loaded substrate W through the resist. is held in a horizontal position so that the main surface on which is provided faces upward (FIG. 6). The nozzles 21 and 22, the film thickness sensor 31, the plasma reactor 41, and the guard 71 are placed at their standby positions so as not to interfere with the hand 131a during this process.

Step S2: First Plasma Processing Step Subsequently, the substrate W held by the holding unit 1 is irradiated with plasma. That is, the substrate W before the liquid film F of the processing liquid is formed (the substrate W with the resist exposed) is irradiated with plasma to perform plasma processing (first plasma processing). This processing step will be specifically described with reference to FIG.

In this processing step, a predetermined voltage (voltage for plasma generation) is applied to the plasma reactor 41 from the power supply 42 . As a result, the gas around the plasma reactor 41 is turned into plasma to generate plasma. This plasma contains various active species (when the gas surrounding the plasma is air, for example, active species such as oxygen radicals, hydroxyl radicals, and ozone gas). It changes depending on the type of gas existing around the reactor 41 and the like.

Also, in this processing step, the valve 613 provided in the gas supply pipe 611 is opened. Then, a predetermined gas stored in the gas supply source 612 is supplied to the gas nozzle 61 through the gas supply pipe 611 at a predetermined flow rate adjusted by the flow rate adjusting section 614, and is discharged from each discharge port 61b. That is, the gas is discharged from outside the peripheral edge of the lower surface of the plasma reactor 41 along a direction that is radial to the lower surface when viewed from above and parallel to the lower surface when viewed from the side. As a result, the gas is supplied to the space below the lower surface of the plasma reactor 41 (the space between the lower surface and the substrate W held by the holding unit 1).

The predetermined gas supplied to the vicinity of the plasma reactor 41 (that is, the predetermined gas discharged from the gas nozzle 61) is a gas that promotes plasma generation. It is a mixed gas of a system gas and a rare gas. Here, the "oxygen-based gas" is a gas containing oxygen atoms, and specifically includes, for example, oxygen gas, ozone gas, carbon dioxide gas, mixed gas containing at least two of these, and the like. . Supplying the oxygen-based gas to the vicinity of the plasma reactor 41 promotes generation of plasma (in particular, generation of oxygen-based active species such as oxygen radicals). As the rare gas, for example, helium gas, argon gas, mixed gas containing at least two of them, or the like can be used. Supplying the rare gas to the vicinity of the plasma reactor 41 promotes generation of plasma (so-called assist gas).

It should be noted that the predetermined gas supplied to the vicinity of the plasma reactor 41 preferably does not contain nitrogen gas. Nitrogen can be a generation source of NOx gas having a reducing action (that is, an action of deactivating oxygen-based active species). The concentration of nitrogen in the vicinity of the plasma reactor 41 is lowered, suppressing the production of NOx gas. As a result, oxygen-based active species are less likely to be deactivated.

Here, as the flow rate of the gas discharged from the gas nozzle 61 increases, the generation of plasma is promoted and the amount of active species in the plasma increases. In order to generate a sufficient amount of active species in plasma, the flow rate of the gas discharged from the gas nozzle 61 is preferably 3 (L/min) or more, for example. However, if the flow rate of the gas discharged from the gas nozzle 61 is too high, active species in the plasma may be swept away by the gas, and a sufficient amount of active species may not reach the substrate W. FIG. In order to suppress the occurrence of such a situation, it is preferable that the flow rate of the gas discharged from the gas nozzle 61 is, for example, 10 (L/min) or less. That is, the flow rate of the gas discharged from the gas nozzle 61 is preferably 3 (L/min) or more and 10 (L/min) or less.

By the way, active species in the plasma generated around the plasma reactor 41 are deactivated in a relatively short time. Therefore, even if a sufficient amount of active species exist at a position close to the plasma reactor 41, most of the active species are deactivated at a position distant from the plasma reactor 41. FIG. Therefore, in order to cause a sufficient amount of active species to act on the substrate W, the plasma reactor 41 is placed on the substrate W so that the distance between the plasma reactor 41 and the substrate W held by the holding unit 1 is sufficiently small. should be close enough to

Therefore, in this processing step, the plasma reactor moving mechanism 43 moves (lowers) the plasma reactor 41 from the plasma standby position to the plasma processing position (first plasma processing position). The descent of the plasma reactor 41 is started, for example, after the voltage application to the plasma reactor 41 is started and the discharge of gas from the gas nozzle 61 is started. However, the timing at which the lowering of the plasma reactor 41 is started is not limited to this. good.

Here, the "first plasma processing position" is a position where the distance between the plasma reactor 41 and the substrate W held by the holding part 1 is the first distance d1. As described above, the smaller the distance between the plasma reactor 41 and the substrate W, the greater the amount of active species acting on the substrate W. In order to allow a sufficient amount of active species to act on the substrate W, the first separation distance d1 is preferably 5 (mm) or less, for example. On the other hand, if the distance between the plasma reactor 41 and the substrate W is too small, a discharge may occur between them. In order to avoid the occurrence of discharge, it is preferable that the first separation distance d1 is, for example, 3 (mm) or more. That is, the first separation distance d1 is preferably 3 (mm) or more and 5 (mm) or less.

The plasma reactor 41 to which the voltage is applied is arranged to face the main surface of the substrate W held by the holder 1 in a state where the plasma reactor 41 is arranged at the first plasma processing position. Plasma is irradiated from the substrate W, and the plasma processing (first plasma processing) for the substrate W progresses. In the first plasma processing, the plasma generated around the plasma reactor 41 directly acts on the resist provided on the main surface of the substrate W. As shown in FIG. Specifically, active species in the plasma react with the resist to oxidize the resist. As a result, decomposition (reduction of molecular weight) of the polymer contained in the resist progresses, and the resist changes into a film that is easily peeled off. If the reaction between the active species and the resist progresses further, the resist may delaminate in addition to the deterioration of the resist. The processing conditions (for example, processing time) are set. That is, the first plasma treatment is positioned as a pretreatment for the second plasma treatment, and the first plasma treatment is limited to altering the resist, while the second plasma treatment, which will be described later, is the main part of stripping the resist. proceed. As a result, damage to the substrate W can be sufficiently reduced.

Further, in this processing step, the rotating mechanism 13 rotates the holding part 1 (and thus the substrate W held therein) about the rotation axis Q orthogonal to the main surface of the substrate W at least while the first plasma treatment is being performed. Rotate around at a predetermined number of revolutions. Even if the distribution of the active species in the plasma generated below the plasma reactor 41 is non-uniform, the rotation of the substrate W allows the active species to be evenly distributed over the entire main surface of the substrate W. Seeds can work. That is, the uniformity of processing within the surface of the substrate W can be improved. In order to sufficiently secure this uniformity, the rotation speed at this time is preferably 5 (rpm) or more, for example. On the other hand, if the number of rotations is too high, it will cause turbulence in the airflow between the plasma reactor 41 and the substrate W, causing an imbalance in the distribution of active species in the plasma (that is, the surface of the substrate W). There is a risk that the uniformity of the processing inside will rather deteriorate). In order to avoid the occurrence of such a situation, it is preferable that the rotation speed is, for example, 20 (rpm) or less. That is, the rotation speed at this time is preferably, for example, 5 (rpm) or more and 20 (rpm) or less.

Furthermore, in this processing step, the guard moving mechanism 72 places the guard 71 (both of the two guards 71 here) at the guard processing position at least while the first plasma processing is being performed. Therefore, when the gas or the like existing between the plasma reactor 41 and the substrate W diffuses to the outside of the substrate W, it is received by the inner peripheral surface of the guard (inside guard) 71, and the inner peripheral surface It flows down along the surface, is received by the peripheral wall portion 741 , and is exhausted from the exhaust pipe 742 .

When a predetermined time has passed since the first plasma processing was started, the valve 613 provided in the gas supply pipe 611 is closed, and the gas discharge from the gas nozzle 61 is stopped. Also, the plasma reactor moving mechanism 43 moves (raises) the plasma reactor 41 from the first plasma processing position to the plasma standby position. Since plasma processing (second plasma processing) is performed again on the substrate W later, voltage application to the plasma reactor 41 is continued here.

Step S<b>3 : Liquid Film Forming Step Subsequently, a liquid film of the processing liquid (here, sulfuric acid) is formed on the substrate W held by the holding section 1 . This step will be specifically described with reference to FIG.

First, the nozzle moving mechanism 23 moves the processing liquid nozzle 21 from the nozzle waiting position to the nozzle processing position. When the processing liquid nozzle 21 is arranged at the nozzle processing position, the valve 213 provided in the processing liquid supply pipe 211 is opened. Then, a predetermined processing liquid (here, sulfuric acid) stored in the processing liquid supply source 212 is supplied to the processing liquid nozzle 21 through the processing liquid supply pipe 211 at a predetermined flow rate adjusted by the flow rate adjusting unit 214 . is discharged from the discharge port 21a. That is, the processing liquid is discharged toward the upper main surface of the substrate W held by the holding unit 1, and the processing liquid is supplied to the substrate W. As shown in FIG.

The rotation mechanism 13 rotates the holding part 1 (and thus the substrate W held here) at a predetermined number of rotations at least while the treatment liquid is being discharged onto the substrate W. As shown in FIG. Therefore, the processing liquid that has landed on a predetermined position (for example, the center of the main surface) on the upper main surface of the substrate W quickly spreads toward the peripheral edge of the substrate W due to the centrifugal force, and spreads over substantially the entire main surface. is formed. The rotation speed at this time is preferably, for example, about 20 (rpm) to 70 (rpm).

Further, at least while the holding part 1 is being rotated, the guard moving mechanism 72 arranges the guards 71 (both of the two guards 71 here) at the guard processing position. Therefore, the processing liquid or the like that scatters from the peripheral edge of the substrate W is received by the inner peripheral surface of the guard (inside guard) 71, flows down along the inner peripheral surface, is further received by the cup 731, and is discharged. Liquid tube 732 is drained. The discharged treatment liquid and the like may be recovered and reused.

After a predetermined period of time has passed since the ejection of the treatment liquid was started, the valve 213 is closed and the ejection of the treatment liquid from the ejection port 21a is stopped. Further, the rotation mechanism 13 reduces the number of rotations of the holder 1 (and thus the substrate W held therein) to a sufficiently low number of rotations, or stops the rotation. The liquid film F is stabilized on the substrate W by rotating the substrate W with the liquid film F formed thereon at a sufficiently low number of revolutions for a predetermined time (or maintaining the state where the rotation is stopped). and held (so-called paddle processing).

Step S4: Film thickness measurement step Subsequently, the thickness (film thickness) of the liquid film F of the treatment liquid formed on the main surface of the substrate W in the liquid film formation step is measured. The thickness of the liquid film F basically depends on the processing conditions of the liquid film forming process (specifically, the flow rate of the processing liquid discharged from the discharge port 21a, the discharge time, the rotation speed of the holding unit 1, etc.). The processing conditions are defined according to the thickness (target film thickness) of the liquid film F to be formed (the target film thickness is, for example, 200 (μm) or more and 500 ( μm) or less). However, even if the processing conditions are set to be the same, the thickness of the actually formed liquid film F may vary slightly among the substrates W. FIG. Especially here, since the film quality of the resist formed on the main surface of the substrate W is changed by the first plasma treatment, it is considered that the thickness of the liquid film F is particularly likely to vary. Therefore, in this step, the thickness of the liquid film F actually formed on the substrate W is measured. This step will be specifically described with reference to FIG.

First, the nozzle moving mechanism 23 (that is, the nozzle moving mechanism 23 as the sensor moving mechanism 32) moves the film thickness sensor 31 to the film thickness measuring position. As described above, the film thickness measurement position is a position that vertically faces the position to be measured, which is defined in advance within the plane of the upper main surface of the substrate W held by the holding unit 1 . When the film thickness sensor 31 is placed at the film thickness measurement position, the film thickness sensor 31 measures the film thickness at the position to be measured, and outputs the acquired film thickness measurement value to the control unit 140 .

In addition, a plurality of positions within the main surface of the substrate W may be set as the measurement target positions. That is, a plurality of film thickness measurement positions may be set corresponding to a plurality of measurement target positions. In this case, the nozzle moving mechanism 23 moves the film thickness sensor 31 along a path connecting a plurality of film thickness measurement positions, and the film thickness sensor 31 is positioned at each film thickness measurement position. Measure the film thickness at the target position. When the measured values of the film thickness at each of the plurality of measurement target positions are acquired, the film thickness sensor 31 calculates, for example, the average value of the plurality of measured values and outputs it to the control section 140 . Arithmetic processing such as calculation of the average value may be performed on the control unit 140 side.

By the way, in the second plasma treatment, which will be described later, the plasma acts from the upper surface side of the liquid film F of the processing liquid. The probability of occurrence near the upper surface of the liquid film F is high. Therefore, the smaller the film thickness of the liquid film F, the easier it is for the substance to reach the substrate W (more specifically, the resist provided on the substrate W), and the more the process (that is, the removal of the resist) proceeds. Cheap. That is, the advancing speed of the second plasma processing increases (that is, becomes faster) as the thickness of the liquid film F of the processing liquid formed on the substrate W becomes smaller (that is, thinner). Therefore, if the second plasma processing is performed under the same processing conditions for the substrates W having different thicknesses of the liquid films F, there is a possibility that the processing may vary among the substrates W.

Therefore, the control unit 140 adjusts the processing conditions of the second plasma processing step based on the measured value of the film thickness obtained from the film thickness sensor 31, so that the processing variations among the substrates W in the second plasma processing are reduced. prevent it from occurring. Specifically, the control unit 140 adjusts at least one of the processing conditions of the second plasma processing step so that the progress speed of the second plasma processing becomes smaller (slower) as the measured value of the film thickness becomes smaller. do. Conversely, the control unit 140 adjusts at least one of the processing conditions of the second plasma processing step so that the progress speed of the second plasma processing increases (increases) as the measured value of the film thickness increases.

One of the processing conditions of the second plasma processing is the position of the plasma reactor 41 (second plasma processing position) in the processing. The separation distance between the plasma reactor 41 and the substrate W held by the holding unit 1 is defined by the second plasma processing position. The larger the amount, the faster the progress of the second plasma treatment.

Therefore, the control unit 140 adjusts the second plasma processing position such that, for example, the smaller the measured value of the film thickness, the larger the separation distance. Conversely, the controller 140 adjusts the second plasma processing position such that the greater the film thickness measurement value, the smaller the separation distance. Specific adjustments may be made in any manner. For example, when the measured value of the film thickness is smaller than the reference value, the second plasma processing position is corrected above the specified position, and when the measured value of the film thickness is larger than the reference value, the second plasma processing The position should be corrected downward from the prescribed position. Needless to say, it is preferable to increase the amount of correction from the prescribed position as the amount of deviation of the measured value of the film thickness from the reference value increases.

One of the processing conditions for the second plasma processing is the plasma output value of the plasma reactor 41 in the processing. Here, the "plasma output value" is a value that indicates the ability to generate plasma. used as an indicator of As the plasma output value increases, the amount of generated plasma increases, and the progress speed of the second plasma processing increases. The plasma output value is determined by the control parameters of the voltage applied to the plasma reactor 41 (specifically, the frequency of the applied voltage, the ratio of the ON period in the pulse signal used for switching voltage application (ON duty ratio), the applied voltage , etc.), and basically, the greater the value of each of these control parameters, the greater the plasma output value.

Therefore, the controller 140 adjusts at least one of the control parameters so that the plasma output value of the plasma reactor 41 decreases as the film thickness measurement value decreases. Conversely, the controller 140 adjusts the value of at least one of the control parameters so that the plasma output value of the plasma reactor 41 increases as the film thickness measurement value increases. Also in this case, the specific adjustment may be made by any method. For example, when the measured value of the film thickness is smaller than the reference value, the value of at least one of these control parameters is corrected to be smaller than the predetermined value, and the measured value of the film thickness is the reference value. The value of at least one of each of these control parameters may be modified to be greater than the default value if greater than the value. Also in this case, it is preferable to increase the amount of correction from the specified value as the amount of deviation of the measured value of the film thickness from the reference value increases.

Step S5: Second Plasma Processing Step Subsequently, the substrate W held in the holding unit 1 is irradiated with plasma to perform plasma processing (second plasma processing). In the first plasma treatment, the substrate W before the liquid film F of the treatment liquid is formed (the substrate W with the resist exposed) is irradiated with plasma. The substrate W on which the liquid film F of the liquid has been formed (the substrate W in which the resist is covered with the liquid film F of the processing liquid) is irradiated with plasma. This processing step will be specifically described with reference to FIG.

As described above, a predetermined voltage is continuously applied to the plasma reactor 41 from the power source 42 even after the first plasma processing step, and the gas (here, air) around the plasma reactor 41 is turned into plasma. As a result, plasma containing various active species (for example, active species such as oxygen radicals, hydroxyl radicals, and ozone gas) is generated. In order to cause this plasma to act on the substrate W held by the holding unit 1 (specifically, the liquid film F of the processing liquid formed on the main surface of the substrate W), the plasma reactor moving mechanism 43 includes: The plasma reactor 41 is moved (lowered) from the plasma standby position to the plasma processing position (second plasma processing position).

Here, the "second plasma processing position" is a position where the separation distance between the plasma reactor 41 and the substrate W held by the holding section 1 is the second separation distance d2. As described above, the smaller the distance between the plasma reactor 41 and the substrate W, the greater the amount of active species acting on the substrate W (here, the liquid film F of the processing liquid formed on the substrate W). In order to allow a sufficient amount of active species to act on the liquid film F, the second separation distance d2 is preferably 3.5 (mm) or less, for example. On the other hand, if the distance between the plasma reactor 41 and the substrate W is too small, a discharge may occur between them. In order to avoid the occurrence of discharge, it is preferable that the second separation distance d2 is, for example, 2 (mm) or more. That is, the second distance d2 is preferably 2 (mm) or more and 3.5 (mm) or less.

Here, discharge is less likely to occur when the liquid film F is formed on the substrate W than when the liquid film F is not formed. In other words, the minimum separation distance that must be ensured to avoid the occurrence of discharge is greater when the liquid film F is formed on the substrate W than when the liquid film F is not formed. small. Therefore, here, the second separation distance d2 is set to a value smaller than the first separation distance d1, that is, the second plasma processing position is set at a position lower than the first plasma processing position. Thereby, in each of the first and second plasma processing steps, it is possible to sufficiently promote the plasma processing while suppressing the occurrence of electrical discharge.

Needless to say, when the second plasma processing position has been adjusted based on the film thickness measurement value obtained in the film thickness measurement step, the plasma reactor 41 is arranged at the adjusted second plasma processing position. be. Further, when the control parameter of the voltage applied to the plasma reactor 41 is adjusted based on the measured value of the film thickness, the voltage applied to the plasma reactor 41 is performed with the adjusted value.

The plasma reactor 41 to which the voltage is applied is arranged to face the main surface of the substrate W held by the holder 1 in a state where the plasma reactor 41 is arranged at the second plasma processing position. Plasma is irradiated from the substrate W, and the plasma processing (second plasma processing) for the substrate W progresses. In the second plasma processing, the plasma generated around the plasma reactor 41 acts on the liquid film F of the processing liquid (here, sulfuric acid) formed on the main surface of the substrate W, whereby the processing liquid Processing performance is improved. Specifically, active species in the plasma react with sulfuric acid to generate caro's acid (peroxomonosulfuric acid: H ₂ SO ₅ ) with high processing performance (here, oxidizing power). Caro's acid acts on the resist provided on the main surface of the substrate W, thereby oxidizing and stripping (removing) the resist. As described above, here, the first plasma treatment is performed prior to the second plasma treatment, and the first plasma treatment changes the resist provided on the main surface of the substrate W into a film that is easily stripped. It is Therefore, even in cases where the resist is relatively difficult to peel off, the resist can be peeled off without difficulty in the second plasma treatment.

Note that gas is not discharged from the gas nozzle 61 in this processing step. That is, the second plasma processing is performed while the supply of the gas that promotes generation of plasma is stopped.

Further, in this processing step, the rotating mechanism 13 rotates the holding unit 1 (and thus the substrate W held therein) about the rotation axis Q perpendicular to the main surface of the substrate W, at least while the second plasma processing is being performed. Rotate around at a predetermined number of revolutions. As described above, even if the distribution of the active species in the plasma generated below the plasma reactor 41 is non-uniform, the substrate W is rotated to form on the main surface of the substrate W. The active species can act evenly over the entire area of the liquid film F. That is, the uniformity of processing within the surface of the substrate W can be improved. In addition, if there is uneven heat in the plane of the plasma reactor 41, the substrate W may be deformed into a concave shape due to the influence thereof, and the liquid film F may be unevenly distributed near the center of the substrate W (which may result in non-uniform processing). However, since the substrate W is rotated, such a situation is less likely to occur. On the other hand, if the rotational speed is too high, the processing liquid may spill from the main surface of the substrate W, or the liquid film F may be unevenly distributed due to centrifugal force. In order to avoid the occurrence of such a situation, the rotation speed is preferably, for example, 30 (rpm) or less, and particularly preferably 20 (rpm) or less.

Also in this processing step, the guard moving mechanism 72 places the guards 71 (both of the two guards 71 here) at the guard processing position at least while the plasma processing is being performed. Therefore, if the gas or mist existing between the plasma reactor 41 and the substrate W (for example, the mist of the processing liquid volatilized by the heat of the plasma reactor 41) diffuses to the outside of the substrate W, this It is received by the inner peripheral surface of the guard (inside guard) 71 , flows down along the inner peripheral surface, is further received by the peripheral wall portion 741 , and is exhausted from the exhaust pipe 742 .

When a predetermined time elapses after the start of the second plasma processing, the voltage application to the plasma reactor 41 is stopped, and the plasma reactor moving mechanism 43 moves the plasma reactor 41 from the second plasma processing position to the plasma standby position ( rise).

Step S6: Rinsing Process Subsequently, the liquid film F of the processing liquid (here, sulfuric acid) is washed away from the substrate W held in the holding section 1 (rinsing process). This step will be specifically described with reference to FIG.

First, the nozzle moving mechanism 23 moves the rinse liquid nozzle 22 from the nozzle waiting position to the nozzle processing position. When the rinse liquid nozzle 22 is arranged at the nozzle processing position, the valve 223 provided in the rinse liquid supply pipe 221 is opened. Then, the predetermined rinse liquid stored in the rinse liquid supply source 222 is supplied to the rinse liquid nozzle 22 through the rinse liquid supply pipe 221 at a predetermined flow rate adjusted by the flow rate adjusting section 224, and is discharged from the discharge port 22a. Dispensed. That is, the rinse liquid is discharged toward the upper main surface of the substrate W held by the holding unit 1, and the substrate W is supplied with the rinse liquid.

At least while the rinse liquid is being discharged onto the substrate W, the rotating mechanism 13 rotates the holding part 1 (and thus the substrate W held here) at a predetermined number of rotations. Therefore, the rinsing liquid that has landed at a predetermined position (for example, the center of the main surface) on the upper main surface of the substrate W quickly spreads toward the peripheral edge of the substrate W due to the centrifugal force, and spreads over substantially the entire main surface. The liquid film F of the processing liquid covering the is replaced with the rinsing liquid. That is, the liquid film F of the processing liquid is washed away.

After a predetermined period of time has elapsed since the start of the rinse liquid discharge, the valve 223 is closed to stop the rinse liquid discharge from the discharge port 22a. On the other hand, the rotation mechanism 13 increases the rotation speed of the holding part 1 to a sufficiently high rotation speed. As a result, the substrate W held by the holding unit 1 is rotated at high speed to dry the substrate W (so-called spin drying).

Here, the guard moving mechanism 72 arranges the outer guard 71 at the guard processing position and the inner guard 71 at the guard waiting position at least while the holding part 1 is rotated. Therefore, the processing liquid, the rinse liquid, and the like scattered from the peripheral edge of the substrate W are received by the inner peripheral surface of the guard 71 on the outside and flow down along the inner peripheral surface. The liquid is received by a cup (not shown) and drained from a drain pipe (not shown) connected thereto.

When the holding part 1 is rotated at a sufficiently high number of revolutions for a predetermined time, the rotation mechanism 13 stops the rotation of the holding part 1 . After the nozzles 21 and 22, the film thickness sensor 31, the plasma reactor 41, and the guard 71 are arranged at their standby positions, the main transfer robot 131 moves the substrate W held by the holding unit 1. Carry out.

After that, another new substrate W is loaded into the processing unit 132, and the new substrate W is subjected to the above-described series of processing (steps S1 to S6).

<4. Effect>
The substrate processing method according to the above embodiment includes a holding step (step S1) of holding the substrate W provided with the resist in the holding unit 1, and irradiating the substrate W held in the holding unit 1 with plasma. a first plasma processing step (step S2); and a liquid film forming step (step S3) of forming a liquid film F of the processing liquid on the substrate W held in the holding unit 1 after the first plasma processing step is performed. Then, after the liquid film forming step is performed, a second plasma processing step (step S5) of irradiating the substrate W held in the holding unit 1 with plasma, and after the second plasma processing step is performed, holding a rinsing step (step S6) of washing away the liquid film F from the substrate W held in the unit 1;

According to this configuration, the substrate W is irradiated with plasma before and after the liquid film F of the processing liquid is formed. When the substrate W is irradiated with plasma before the liquid film F of the processing liquid is formed (first plasma processing step), the plasma directly acts on the resist to decompose the polymer contained in the resist (low molecular weight ) progresses, and the resist is changed into a film that is easy to peel off. On the other hand, in the irradiation of the plasma onto the substrate W after the liquid film F of the processing liquid has been formed (the second plasma processing step), the plasma acts on the processing liquid, thereby enhancing the processing capability of the processing liquid. Detachment of the resist due to progresses. Specifically, active species contained in the plasma react with sulfuric acid to generate caro's acid with high processing performance, and the caro's acid reacts with the resist, thereby progressing stripping of the resist. In other words, in this configuration, the resist film quality is changed into a state that is easy to peel off by the plasma irradiation in the first plasma processing step, and then the processing liquid whose processing ability is enhanced by the plasma irradiation in the second plasma processing step Stripping of the resist is performed. Therefore, even if the resist is relatively difficult to peel off, it can be peeled off without difficulty. That is, the ability to remove the resist can be improved.

Cases in which the resist is relatively difficult to peel off include, for example, when the film thickness of the resist is relatively large (for example, about several micrometers), and when the ion implantation dose is relatively large (for example, the dose is 1E16 (ion/cm ² ) above), and the case where the resist contains a polymer that is difficult to peel off (for example, a polymer that is not compatible with the processing solution used). In these cases, if the resist is stripped only by the second plasma treatment, the treatment time will be long, the amount of the treatment solution used will be large, and the plasma output value will have to be increased considerably, resulting in high power consumption. However, by performing the first plasma treatment before the second plasma treatment, such inconvenience can be avoided. That is, it is possible to shorten the processing time required for the second plasma processing, reduce the amount of processing liquid used, and reduce power consumption (power saving). Further, even in cases where the resist is particularly difficult to strip and the resist cannot be sufficiently stripped only by the second plasma treatment, the resist can be stripped by performing the first plasma treatment before the second plasma treatment. there is a possibility.

Further, in the substrate processing method according to the above embodiment, the processing conditions (for example, the processing time) are set so that the first plasma processing ends before the resist provided on the substrate W is peeled off. be done. That is, here, the first plasma treatment is positioned as a pretreatment for the second plasma treatment, and the resist stripping proceeds mainly in the second plasma treatment. As a result, damage to the substrate W can be sufficiently reduced.

Further, the substrate processing method according to the above embodiment includes a film thickness measuring step (step S4) of measuring the thickness of the liquid film F formed in the liquid film forming step. In the liquid film forming process, the thickness of the actually formed liquid film F may vary slightly among the substrates W even if the processing conditions are set to be the same. Further, when the substrate W is irradiated with plasma before the liquid film F is formed and the film quality of the resist is degraded, it is considered that this variation is particularly likely to occur. If there is variation in the thickness of the liquid film F among the substrates W, the progress speed of the plasma processing in the second plasma processing step will vary, and the uniformity of the processing among the substrates W may not be ensured. By measuring the thickness of F, it is possible to perceive a situation in which such variations may occur.

Further, in the substrate processing method according to the above embodiment, the processing conditions of the second plasma processing step are adjusted based on the measured value obtained in the film thickness measuring step. Therefore, even if there is a variation in the thickness of the liquid film F among the substrates W, it is possible to adjust the processing conditions of the second plasma processing step so as to offset this variation (specifically, for example, by measuring the thickness of the film). At least one of the processing conditions of the second plasma processing is adjusted in the direction of decreasing (slowing) the advancing speed of the second plasma processing as the value is smaller, and the second plasma processing is adjusted as the measured value of the film thickness is larger. By adjusting at least one of the processing conditions of the second plasma processing in the direction of increasing (increasing) the advancing speed of the wafer W, it is possible to avoid the occurrence of variations in processing between substrates W.

Further, in the substrate processing method according to the above embodiment, the gas that promotes generation of plasma is supplied in the first plasma processing step. According to this configuration, the first plasma treatment can be effectively advanced. In particular, the amount of gas supplied in the first plasma treatment step is 3 (L/min) or more and 10 (L/min) or less, thereby sufficiently promoting plasma generation, It is possible to suppress the occurrence of a situation in which the active species in the plasma are swept away by the gas flow and cannot reach the substrate W.

Further, in the substrate processing method according to the above embodiment, the second plasma processing step is performed while the supply of the gas that promotes generation of plasma is stopped. According to this configuration, the liquid film F formed on the substrate W is not shaken or washed away by the gas flow. Therefore, uniformity of processing within the surface of the substrate W is sufficiently ensured.

Further, in the substrate processing method according to the above-described embodiment, in the first plasma processing step, the plasma irradiation unit (plasma reactor) 41 disposed facing the main surface of the substrate W held by the holding unit 1 emits plasma to the substrate W. While irradiating the substrate W with plasma, the substrate W is rotated at a predetermined number of revolutions around a rotation axis Q orthogonal to the main surface, the predetermined number of revolutions being 5 (rpm) or more, and 20 (rpm) or less. Even if the distribution of the active species in the plasma is non-uniform, by rotating the substrate W, the active species can act on the entire main surface of the substrate W evenly. The uniformity of processing within the plane of W can be improved. On the other hand, if the number of rotations of the substrate W is too high, it causes turbulence in the airflow and causes an imbalance in the distribution of the active species in the plasma (that is, the uniformity of the processing in the plane of the substrate W). However, by setting the rotational speed to 20 (rpm) or less, such a situation can be avoided.

Further, in the substrate processing method according to the above embodiment, in the second plasma processing step, the substrate W is irradiated with plasma from the plasma reactor 41 arranged opposite to the main surface of the substrate W held by the holding unit 1. At the same time, the substrate W is rotated at a predetermined number of revolutions around a rotation axis Q perpendicular to the main surface, and the predetermined number of revolutions is 30 (rpm) or less. According to this configuration, even if the distribution of the active species in the plasma is non-uniform, the substrate W is rotated so that the active species can act evenly over the entire area of the liquid film F. Therefore, the uniformity of processing within the surface of the substrate W can be improved. On the other hand, if the number of rotations of the substrate W is too high, the liquid film F formed on the substrate W may shake or become uneven, and the uniformity of processing within the surface of the substrate W may deteriorate. However, in this configuration, the occurrence of such a situation is sufficiently avoided.

Further, in the substrate processing method according to the above-described embodiment, in the first plasma processing step, the plasma reactor is arranged to face the main surface of the substrate W held by the holding unit 1 while providing the first separation distance d1. From 41, plasma is irradiated to the substrate W, and in the second plasma treatment step, a second separation distance d2 smaller than the first separation distance d1 is formed between the main surface of the substrate W held by the holding unit 1 and the main surface of the substrate W. , the substrate W is irradiated with plasma from the plasma reactor 41 arranged oppositely. That is, here, the distance between the substrate W and the plasma reactor 41 is different between the first plasma processing step and the second plasma processing step. The smaller the separation distance, the more the plasma processing is promoted. Here, when the liquid film F is formed on the substrate W, discharge is less likely to occur than when the liquid film F is not formed. That is, the minimum separation distance that must be ensured to avoid discharge is smaller when the liquid film F is formed on the substrate W than when the liquid film F is not formed. In the above configuration, the separation distance d2 between the substrate W and the plasma reactor 41 in the second plasma processing step is smaller than the separation distance d1 between the substrate W and the plasma reactor 41 in the first plasma processing step. In each of the first and second plasma processing steps, it is possible to sufficiently promote the plasma processing while suppressing the occurrence of electrical discharge.

Further, the substrate processing apparatus (processing unit) 132 according to the above embodiment includes a holding section 1 that holds the substrate W, a plasma reactor 41 that irradiates the substrate W held by the holding section 1 with plasma, the holding section 1 a processing liquid supply unit for supplying the processing liquid to the substrate W held in the substrate W to form a liquid film F of the processing liquid on the substrate W; a control unit 140 for irradiating the substrate W before the liquid film F is formed thereon, and the control unit 140 irradiates the substrate W after the liquid film F is formed thereon. Irradiate with plasma.

According to this configuration, the substrate W before the liquid film F of the processing liquid is formed is irradiated with the plasma, and the substrate W after the liquid film F is formed is also irradiated with the plasma. By the former plasma irradiation, the film quality of the resist is changed into a state that is easy to peel off, and then the resist is stripped by the processing liquid whose processing ability has been enhanced by the latter plasma irradiation, so that the resist is relatively stripped. Even in difficult cases, it can be peeled off without difficulty. That is, the ability to remove the resist can be improved. Further, here, since the former and the latter plasma irradiation are performed by the same device, for example, the substrate W before the liquid film F of the processing liquid is formed is irradiated with the plasma by the first device. Compared to the configuration in which the substrate W is transferred from the first apparatus to the second apparatus and the substrate W on which the liquid film F is formed is irradiated with plasma in the second apparatus, the processing is It saves a lot of time.

Moreover, the plasma reactor 41 provided in the substrate processing apparatus according to the above-described embodiment is a plate-like member, and is capable of planarly generating plasma over the entire main surface thereof. The planar action of the plasma on the main surface of the substrate W held by the holding unit 1 improves the uniformity of processing within the main surface.

<5. Variation>
<5-1. First modification>
In the above-described embodiment, in the second plasma processing step, the supply of the gas that promotes the generation of plasma (that is, the discharge of the predetermined gas from the gas nozzle 61) is not performed, but this may be performed. That is, in the second plasma processing step, the valve 613 provided in the gas supply pipe 611 may be opened to discharge a predetermined gas from the gas nozzle 61 . The timing of starting gas discharge and the timing of starting lowering of the plasma reactor 41 may be in any order. For example, the discharge of gas from the gas nozzle 61 may be started before the plasma reactor 41 starts to descend.

Also in this case, as the gas to be supplied (that is, the gas discharged from the gas nozzle 61), an oxygen-based gas or a mixed gas of an oxygen-based gas and a rare gas can be used. As described above, the supply of the oxygen-based gas to the vicinity of the plasma reactor 41 promotes generation of plasma (in particular, generation of oxygen-based active species such as oxygen radicals). In addition, the supply of the rare gas to the vicinity of the plasma reactor 41 promotes the generation of plasma. It is also preferable that the gas to be supplied does not contain nitrogen gas.

According to this modification, in the second plasma processing step, the second plasma processing can be effectively advanced by supplying a gas that promotes generation of plasma.

Further, here, the gas nozzle 61 extends along the radial direction of the lower surface when viewed from above and parallel to the lower surface when viewed from the side, from outside the peripheral edge of the lower surface of the plasma reactor 41. Exhale gas. That is, the gas is discharged in a direction parallel to the main surface of the substrate W held by the holding unit 1 (and thus the upper surface of the liquid film F formed here). Therefore, it is possible to suppress the occurrence of a situation in which the liquid film F is shaken or swept away by the gas flow (as a result, the uniformity of the processing within the surface of the substrate W is reduced in the second plasma processing). can be done.

<5-2. Second modification>
In the second plasma processing, when gas is discharged from the gas nozzle 61, the flow rate of the discharged gas is also one of the processing conditions of the second plasma processing. That is, the greater the flow rate of the discharged gas, the greater the amount of active species generated in the plasma, and the faster the progress of the second plasma processing.

Therefore, the flow rate of the gas discharged from the gas nozzle 61 can be used as the processing condition of the second plasma processing step to be adjusted based on the film thickness measurement value obtained in the film thickness measuring step (step S4). . In this case, for example, the controller 140 adjusts the flow rate of the discharged gas to be smaller as the measured value of the film thickness is smaller. Conversely, the controller 140 adjusts the flow rate so that the larger the measured value of the film thickness, the larger the flow rate. Specific adjustments may be made in any manner. For example, if the measured value of the film thickness is smaller than the standard value, the gas discharge flow rate is corrected to be smaller than the default value, and if the measured value of the film thickness is greater than the standard value, the gas discharge flow rate is corrected. should be modified to be larger than the default value. Here, too, it is preferable to increase the amount of correction from the specified value as the amount of deviation of the measured value of the film thickness from the reference value increases.

<5-3. Third modification>
In the second plasma processing step, when gas is discharged from the gas nozzle 61, depending on the height of the plasma reactor 41 (that is, the distance between the substrate W held by the holding unit 1 and the plasma reactor 41), The flow rate of the gas discharged from the gas nozzle 61 may be switched. The flow of processing in this case will be described with reference to FIG. FIG. 12 is a diagram for explaining a manner in which the discharge flow rate of the gas is switched according to the height of the plasma reactor 41. As shown in FIG.

For example, as shown in the upper part of FIG. 12, the plasma reactor 41 is moved from the plasma standby position (the position indicated by the dashed line) to a predetermined midway position (for example, a predetermined distance d20 such that the separation distance d20 is 10 (mm) or more). position), the flow rate adjusting unit 614 sets the flow rate of the gas discharged from the gas nozzle 61 to the first flow rate, and the gas is discharged from the gas nozzle 61 at the first flow rate. After reaching the halfway position, the plasma reactor 41 may be stopped at the halfway position for a predetermined period of time, and the gas may continue to be discharged at the first flow rate while the plasma reactor 41 is stopped.

After that, as shown in the lower part of FIG. 12, the plasma reactor 41 is lowered from the midway position (the position indicated by the dashed line) to the second plasma processing position. At the start of this descent (or prior to the start of descent, during the descent, or at the end of the descent), the flow rate adjusting unit 614 adjusts the amount of gas discharged from the gas nozzle 61. is switched from a first flow rate to a second smaller flow rate. After such switching, the gas is discharged from the gas nozzle 61 at a second flow rate that is smaller than the first flow rate. The discharge of gas at the second flow rate is continued, for example, until the second plasma processing ends.

When the plasma reactor 41 is at a relatively high position (that is, when the distance between the substrate W and the plasma reactor 41 is relatively large), the liquid film F formed on the substrate W is affected by the gas flow. Hateful. In addition, since the pressure loss when supplying gas between the two is relatively small, the gas flows easily. Therefore, in such a state, by supplying gas from the gas nozzle 61 at a relatively large flow rate, it is possible to prevent the liquid film F from being shaken or washed away by the gas flow. and the plasma reactor 41 can be rapidly replaced.

On the other hand, when the plasma reactor 41 is at a relatively low position (that is, when the distance between the substrate W and the plasma reactor 41 is relatively small), the liquid film F formed on the substrate W is affected by the gas flow. It is easy to be shaken or swept away by receiving Further, in such a state, turbulence of the airflow between the plasma reactor 41 and the substrate W is likely to occur due to the supplied gas. Therefore, in such a state, by supplying gas from the gas nozzle 61 at a relatively small flow rate, it is possible to sufficiently suppress the occurrence of a situation in which the liquid film F is shaken or swept away by the gas flow. can. In addition, it is possible to suppress the occurrence of airflow turbulence (and thus the occurrence of imbalance in the distribution of active species).

The mode of switching the flow rate of the gas discharged from the gas nozzle 61 according to the height of the plasma reactor 41 is not limited to the above example. For example, when the plasma reactor 41 reaches a predetermined intermediate position, discharge of the gas at the first flow rate is started, and the state in which the gas is discharged at the first flow rate while the plasma reactor 41 is arranged at the intermediate position is set to a predetermined state. After maintaining for a period of time, the descent of the plasma reactor 41 is resumed, and at the same time, the flow rate adjusting unit 614 may switch the discharge flow rate of the gas from the first flow rate to a second, smaller flow rate. Alternatively, for example, the gas may be discharged at a predetermined flow rate until the plasma reactor 41 reaches a predetermined intermediate position, and the flow rate of the gas may be switched to zero when the plasma reactor 41 reaches the intermediate position. (That is, gas discharge may be stopped.).

Note that this modification may be applied when a predetermined gas is discharged from the gas nozzle 61 in the first plasma processing step. That is, in the first plasma processing step, when the gas is discharged from the gas nozzle 61 , the flow rate of the discharged gas may be switched according to the height of the plasma reactor 41 .

<5-4. Other Modified Examples of Processing Flow>
The flow of processing performed by the processing unit 132, the content of the processing, and the like are not limited to those illustrated in the above embodiments.

For example, in the above embodiment, the holder 1 (and thus the substrate W held therein) is rotated while the second plasma treatment is being performed. The part 1 (and thus the substrate W held here) need not be rotated. That is, while the second plasma processing is being performed, the rotating mechanism 13 may stop the holder 1 without rotating it. With this configuration, it is possible to suppress the liquid film F formed on the substrate W from shaking or becoming biased. Therefore, uniformity of processing within the surface of the substrate W is sufficiently ensured.

Further, in the above embodiment, the holder 1 (and thus the substrate W held therein) is rotated while the first plasma treatment is being performed. The part 1 (and thus the substrate W held here) need not be rotated. That is, while the first plasma processing is being performed, the rotating mechanism 13 may stop the holder 1 without rotating it. However, in the first plasma treatment, the plasma directly acts on the resist provided on the substrate W. Therefore, if the rotation is not performed, the nonuniformity of the distribution of the active species in the plasma affects the surface of the substrate W. It appears directly as non-uniformity of processing inside. Therefore, when the distribution of active species is not sufficiently uniform, it is preferable to rotate the substrate W while performing the first plasma treatment.

Further, in the above embodiment, the voltage application to the plasma reactor 41 is continued even after the first plasma processing is completed. The voltage value of the applied voltage, the frequency of the applied voltage, the ratio of the ON period in the pulse signal used for controlling the voltage application (on-duty ratio), etc.) may be switched. For example, the value of at least one parameter may be switched to a relatively small value between the end of the first plasma treatment process and the start of the second plasma treatment process. In addition, the voltage application does not necessarily have to be continued. For example, when the first plasma treatment process is completed, the voltage application is stopped, and when the second plasma treatment process is started, the voltage application is stopped. You can restart.

In addition, in each of the first plasma processing step and the second plasma processing step, the timing of applying the voltage to the plasma reactor 41 may be before, during or after the plasma reactor 41 is lowered. . However, a certain amount of time is required from the start of voltage application to the plasma reactor 41 until the plasma stabilizes. By starting the application of the voltage halfway), sufficiently stable plasma can be caused to act on the substrate W (or the liquid film F of the processing liquid provided on the main surface thereof). That is, it is possible to avoid a situation in which unstable plasma (for example, plasma that is not sufficiently uniform) acts on the substrate W to make the processing non-uniform.

Further, in the first plasma processing step, the timing of starting gas discharge from the gas nozzle 61 may be before, during or after the plasma reactor 41 is lowered. Further, the timing of starting gas ejection from the gas nozzle 61 may be before, at the same time as, or after the voltage application to the plasma reactor 41 is started. The same applies when discharging gas from the gas nozzle 61 in the second plasma processing step.

In the above embodiment, the predetermined gas supplied to the vicinity of the plasma reactor 41 in the first plasma processing step is, for example, an oxygen-based gas or a mixed gas of an oxygen-based gas and a rare gas. , the type of gas to be supplied is not limited to this. For example, only noble gases may be supplied. Further, gas may not be supplied in the first plasma processing step.

Similarly, when a predetermined gas is supplied to the vicinity of the plasma reactor 41 in the second plasma processing step, the predetermined gas is limited to an oxygen-based gas or a mixed gas of an oxygen-based gas and a rare gas. isn't it. For example, only noble gases may be supplied. Also, the gas supplied in the second plasma processing step may be the same type as the gas supplied in the first plasma processing step, or may be of a different type.

Moreover, in the above embodiment, the processing conditions of the second plasma processing are adjusted according to the measured value of the film thickness, but the specific adjustment may be made by any method. For example, data describing the correspondence relationship between the film thickness measurement value and the adjustment value (for example, data described in an appropriate method such as a lookup table method, a function method, etc.) is stored in the storage device 144, The control unit 140 may specify the adjustment value from the film thickness measurement value by referring to the data.

Moreover, in the above embodiment, the processing conditions of the second plasma processing step are adjusted based on the measured value obtained in the film thickness measuring step, but such adjustment may not be performed. For example, instead of (or prior to) such adjustment, determining whether the resulting measurement is within a predetermined tolerance range; If there is not, a process (for example, ringing an alarm, lighting a warning lamp, etc.) may be performed to notify the operator of the fact. Also, the film thickness measurement process is not essential and may be omitted.

Further, in the above-described embodiment, the thickness of the liquid film F is measured on the assumption that the thickness of the liquid film F may vary even if the processing conditions in the liquid film forming step are set to be the same. The processing conditions of the second plasma processing step were adjusted based on the obtained measured values. However, needless to say, it is effective to measure the thickness of the liquid film F even when the processing conditions of the liquid film forming process are changed in order to respond to changes in the target film thickness. It is also effective to adjust the processing conditions of the second plasma processing step based on the measured values.

Further, in the above embodiment, the plasma generating section 4 generates plasma under atmospheric pressure, but it may generate plasma under low pressure. That is, a pump is provided for depressurizing the inner space of the chamber 8, and in a state in which the inner space of the chamber 8 is depressurized to a predetermined pressure by the pump, a voltage is applied to the plasma reactor 41 to generate plasma. good too.

Further, in the above embodiment, the processing unit 132 performs the processing of removing the resist formed on the substrate W, but the processing performed in the processing unit 132 is not limited to this. For example, the processing unit 132 may perform processing for removing organic substances (eg, organic particles, organic layers, organic films) existing on the substrate W. FIG.

Further, in the above embodiment, sulfuric acid is used as the processing liquid, but the processing liquid is not limited to this. For example, a chemical liquid containing at least one of sulfuric acid, sulfate, peroxosulfate, and peroxosulfate may be used as the treatment liquid. Also, a chemical solution containing hydrogen peroxide may be used as the treatment liquid, for example, a mixture of sulfuric acid and hydrogen peroxide solution may be used as the treatment liquid. Furthermore, depending on the purpose of the plasma treatment, the type of object to be removed, etc., chemical solutions such as SC1 (mixed solution of hydrogen peroxide solution and ammonia), SC2 (mixed solution of hydrogen peroxide solution and hydrochloric acid) (so-called A cleaning chemical) may be used as the processing liquid, or a chemical such as hydrofluoric acid, hydrochloric acid, or phosphoric acid (so-called etching chemical) may be used as the processing liquid.

Further, in the above-described embodiment, the series of processes (steps S2 to S6) from the first plasma processing step to the rinsing step were performed once for one substrate W. The series of processes may be repeated multiple times on the substrate W of . For example, as shown in FIG. 13, after the rinsing process (step S6) is completed, the number of times (the number of executions) of a series of processes (steps S2 to S6) from the first plasma treatment process to the rinsing process has been performed. determines whether or not a predetermined number of repetitions has been reached (step S7), and if the number of executions has not reached the number of repetitions (number of executions<number of repetitions), the steps from the first plasma treatment step to the rinsing step are repeated again. A series of processes may be repeated (repeated process). In this case, the number of repetitions may be appropriately defined according to the resist type, film thickness, ion implantation dose, and the like.

<5-5. Modification of Configuration of Processing Unit 132>
The configuration of the processing unit 132 is not limited to those illustrated in the above embodiments.

For example, in the above-described embodiment, the treatment liquid nozzle 21 that ejects the treatment liquid and the rinse liquid nozzle 22 that ejects the rinse liquid are separately provided. may alternatively be ejected. In this case, the processing liquid supply pipe 211 and the rinse liquid supply pipe 221 may be connected to the single nozzle.

In the above embodiment, the nozzle moving mechanism 23 moves the processing liquid nozzle 21 and the rinsing liquid nozzle 22 integrally. The nozzles 21, 22 may be moved independently. Needless to say, in this case, the two nozzles 21 and 22 need not be connected. Alternatively, at least one of the two nozzles 21 and 22 may be fixed. That is, the nozzle moving mechanism may be omitted for at least one nozzle.

In the above embodiment, the nozzles 21 and 22 and the film thickness sensor 31 are integrally moved (that is, the nozzle moving mechanism 23 for moving the nozzles 21 and 22 moves the film thickness sensor 31). ), the nozzle moving mechanism 23 and the sensor moving mechanism 32 are provided separately and independently, and the nozzles 21 and 22 and the film thickness sensor 31 are moved separately and independently. You may let Needless to say, in this case, it is not necessary to connect the film thickness sensor 31 to the nozzles 21 and 22 .

In the above-described embodiment, the holding unit 1 holds the substrate W in a horizontal posture by gripping the peripheral edge of the substrate W with the chuck pins 12, but the method for holding the substrate W is limited to this. It does not have to be something that can be used, but it can be anything. For example, the holding section may hold the substrate W in a horizontal posture by sucking the rear surface of the substrate W with a suction mechanism provided on the upper surface of the base section 11 .

Further, in the above embodiment, the gas nozzle 61 has a configuration in which a plurality of discharge ports 61b are provided in a ring-shaped nozzle main body 61a that surrounds the plasma reactor 41 from the side. The configuration is not limited to this. For example, the gas nozzle may have a shape in which a compact nozzle having one outlet hangs downward from the outer side of the periphery of the plasma reactor 41 . Also, such compact nozzles may be provided at a plurality of locations on the periphery of the plasma reactor 41 .

Also, in the above embodiment, the gas nozzle 61 is provided in the plasma reactor 41 , but the gas nozzle 61 does not necessarily have to be provided in the plasma reactor 41 . For example, the gas nozzles may be provided on the blocking plate 51 . Further, for example, the gas nozzle may be provided separately from both the plasma reactor 41 and the blocking plate 51 . In the latter case, it is also preferable to provide a mechanism for raising and lowering the gas nozzle (gas nozzle moving mechanism) in order to dispose the gas nozzle at a predetermined relative position with respect to the plasma reactor 41 .

Also, the plasma reactor moving mechanism 43 for moving the plasma reactor 41 is not essential, and the plasma reactor 41 may be fixedly provided. In this case, for example, a mechanism for raising and lowering the base section 11 is provided, and by raising and lowering the base section 11, the separation distance between the substrate W held on the base section 11 and the plasma reactor 41 may be changed.

Also, the guard moving mechanism 72 for moving the guard 71 is not essential, and the guard 71 may be fixedly provided. Also in this case, for example, a mechanism for raising and lowering the base portion 11 may be provided to raise and lower the base portion 11, thereby changing the positional relationship between the substrate W held on the base portion 11 and the guard 71.

<5-6. Modification of Configuration of Substrate Processing System 100>
The configuration of the substrate processing system 100 is not limited to those illustrated in the above embodiments.

For example, the number of processing units 132 provided in the substrate processing system 100 need not be twelve. Further, for example, the number of load ports 111 provided in the substrate processing system 100 may not be three.

Moreover, the program P may be stored in a recording medium, and the program P may be installed in the control unit 140 using this recording medium.

Further, the substrate W to be processed in the substrate processing system 100 may not necessarily be a semiconductor substrate. For example, substrates W to be processed include photomask glass substrates, liquid crystal display glass substrates, plasma display glass substrates, FED (Field Emission Display) substrates, optical disk substrates, magnetic disk substrates, and magneto-optical disk substrates. substrate, etc. Also, the shape and size of the substrate W to be processed are not limited to those illustrated above. For example, the shape of the substrate W to be processed may be a rectangular plate shape.

Although the substrate processing method and the substrate processing apparatus have been described in detail as above, the above description is illustrative in all aspects, and the substrate processing method and the substrate processing apparatus are not limited to this. It is understood that numerous variations not illustrated can be envisioned without departing from the scope of this disclosure. Each configuration described in each of the above embodiments and each of the above modifications can be appropriately combined or omitted as long as they do not contradict each other.

1 holding part 2 liquid supply part 21 treatment liquid nozzle 22 rinse liquid nozzle 3 film thickness measurement part 31 film thickness sensor 4 plasma generation part 41 plasma reactor 42 power supply 43 plasma reactor moving mechanism 6 gas supply part 61 gas nozzle 132 substrate processing apparatus (processing unit)
100 substrate processing system

Claims (10)

a holding step of holding a substrate provided with a resist on a holding portion;
a first plasma processing step of irradiating the substrate held by the holding part with plasma;
a liquid film forming step of forming a liquid film of the processing liquid on the substrate held by the holding unit after the first plasma processing step is performed;
a second plasma processing step of irradiating the substrate held by the holding part with plasma after the liquid film forming step;
a rinsing step of washing away the liquid film from the substrate held by the holding unit after the second plasma processing step is performed;
A substrate processing method comprising: The substrate processing method according to claim 1,
a film thickness measuring step of measuring the thickness of the liquid film formed in the liquid film forming step;
A substrate processing method comprising: The substrate processing method according to claim 2,
Adjusting the processing conditions of the second plasma processing step based on the measured value obtained in the film thickness measurement step;
Substrate processing method. The substrate processing method according to any one of claims 1 to 3,
In the first plasma processing step, supplying a gas that promotes generation of plasma;
Substrate processing method. The substrate processing method according to any one of claims 1 to 4,
The second plasma treatment step is performed with the supply of the gas that promotes plasma generation stopped.
Substrate processing method. The substrate processing method according to any one of claims 1 to 4,
In the second plasma treatment step, supplying a gas that promotes generation of plasma;
Substrate processing method. The substrate processing method according to any one of claims 1 to 6,
In the first plasma processing step, while irradiating the substrate with plasma from a plasma irradiator arranged opposite to the main surface of the substrate held by the holding unit, the substrate is rotated along a rotation axis perpendicular to the main surface. It rotates at a predetermined number of revolutions around
The predetermined rotation speed is 5 (rpm) or more and 20 (rpm) or less,
Substrate processing method. The substrate processing method according to any one of claims 1 to 7,
In the second plasma processing step, while irradiating the substrate with plasma from a plasma irradiator arranged opposite to the main surface of the substrate held by the holding unit, the substrate is rotated along a rotation axis perpendicular to the main surface. Do not rotate around, or rotate at a speed of 30 (rpm) or less,
Substrate processing method. The substrate processing method according to any one of claims 1 to 8,
In the first plasma treatment step, the substrate is irradiated with plasma from a plasma irradiating unit arranged opposite to the main surface of the substrate held by the holding unit while providing a first separation distance from the main surface of the substrate,
In the second plasma treatment step, from the plasma irradiating unit arranged opposite to the main surface of the substrate held by the holding unit while providing a second separation distance smaller than the first separation distance, irradiating the substrate with plasma;
Substrate processing method. a holding part that holds the substrate;
a plasma irradiation unit that irradiates the substrate held by the holding unit with plasma;
a processing liquid supply unit that supplies a processing liquid to the substrate held by the holding unit to form a liquid film of the processing liquid on the substrate;
a control unit that irradiates the substrate held by the holding unit with plasma from the plasma irradiation unit;
with
The control unit causes the substrate before the liquid film is formed to be irradiated with plasma, and further causes the substrate after the liquid film is formed to be irradiated with plasma.
Substrate processing equipment.

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