JP7270863B1 - Method for cleaning mounting table in plasma processing apparatus and plasma processing apparatus - Google Patents

Abstract

An object of the present invention is to remove deposits deposited on the outer periphery of a mounting table while suppressing damage to the mounting table.
A cleaning method is a method for cleaning a mounting table in a plasma processing apparatus, and has a separating step and a removing step. In the separating step, the mounting table and the substrate are separated using an elevating mechanism. In the removing step, after the step of isolating, plasma is generated by supplying high-frequency power from a high-frequency power supply to the mounting table to remove the deposit deposited on the mounting table. In the separation step, the separation distance between the mounting table and the substrate is set so that the combined impedance formed around the periphery of the mounting table is lower than the combined impedance formed directly above the central portion of the mounting table. be done.
[Selection drawing] Fig. 2

Description

The disclosed embodiments relate to a method for cleaning a mounting table in a plasma processing apparatus and a plasma processing apparatus.

2. Description of the Related Art Conventionally, in a plasma processing apparatus, there is known a technique of using plasma to remove deposits deposited on a mounting table on which a substrate such as a semiconductor wafer is mounted.

JP 2011-054825 A JP-A-7-78802

The present disclosure provides a technique capable of removing deposits deposited on the outer periphery of the mounting table while suppressing damage to the mounting table.

A cleaning method according to an aspect of the present disclosure is a mounting table in a plasma processing apparatus including a mounting table on which a substrate is mounted, an elevating mechanism that moves the substrate up and down with respect to the mounting table, and a high-frequency power source connected to the mounting table. cleaning method. A cleaning method according to one aspect of the present disclosure includes separating and removing. In the separating step, the mounting table and the substrate are separated using an elevating mechanism. In the removing step, after the step of isolating, plasma is generated by supplying high-frequency power from a high-frequency power supply to the mounting table to remove the deposit deposited on the mounting table. In the separation step, the separation distance between the mounting table and the substrate is set so that the combined impedance formed around the periphery of the mounting table is lower than the combined impedance formed directly above the central portion of the mounting table. be done.

According to the present disclosure, it is possible to remove deposits accumulated on the outer peripheral portion of the mounting table while suppressing damage to the mounting table.

FIG. 1 is a schematic cross-sectional view showing the configuration of a plasma processing apparatus according to one embodiment. FIG. 2 is a flowchart showing an example of cleaning processing. FIG. 3 is a diagram showing an example of distribution of plasma generated when high-frequency power is supplied while the wafer is mounted on the mounting table. FIG. 4 is a diagram showing an example of distribution of plasma generated when high-frequency power is supplied while the wafer is separated from the mounting table. FIG. 5 is a graph showing the relationship between the separation distance between the wafer and the mounting surface and the etching rate of the resist film at each position on the upper surface of the wafer. FIG. 6 is a graph showing the relationship between the distance between the wafer and the mounting surface and the etching rate of the resist film at each position on the lower surface of the wafer. FIG. 7 is a graph showing the relationship between the distance between the wafer and the mounting surface and the etching rate of the resist film at each position on the focus ring.

Hereinafter, embodiments of a method for cleaning a mounting table in a plasma processing apparatus and a plasma processing apparatus disclosed in the present application will be described with reference to the drawings. Note that the present disclosure is not limited by the present embodiment. Each embodiment can be appropriately combined as long as the processing contents are not inconsistent.

2. Description of the Related Art Conventionally, a plasma processing apparatus is known that performs plasma processing on a substrate such as a semiconductor wafer. Such a plasma processing apparatus has, for example, a mounting table for mounting a substrate in a processing container capable of forming a vacuum space. Lifter pins are housed inside the mounting table, and the plasma processing apparatus uses the lifter pins to transfer the substrate.

In the plasma processing apparatus, deposits made of reaction products such as CF-based polymers are deposited on the mounting surface of the mounting table by performing plasma processing. Accumulation of deposits on the mounting surface may cause an abnormality such as poor adsorption of the substrate. Therefore, in the plasma processing apparatus, dry cleaning is performed to remove deposits deposited on the mounting surface by plasma processing.

Here, for example, when the diameter of the mounting surface is smaller than the diameter of the wafer, the reaction product of the processing gas used for plasma processing enters between the outer peripheral portion of the mounting table and the back surface of the wafer, causing the mounting table to be deformed. Deposits may accumulate locally on the outer periphery. A structure such as a focus ring is arranged around the outer periphery of the mounting table. Therefore, the peripheral portion of the mounting table is less likely to come into contact with the plasma than the central portion. Therefore, deposits tend to remain on the outer periphery of the mounting table after dry cleaning.

Thus, deposits tend to accumulate more easily on the peripheral portion of the mounting table than on the central portion of the mounting table.

In order to remove deposits deposited on the outer periphery of the mounting table, for example, it is conceivable to lengthen the dry cleaning time. However, if the dry cleaning time is lengthened, the mounting table will be damaged more, and there is a possibility that the life of the mounting table will be shortened.

Therefore, it is expected to remove deposits accumulated on the mounting table while suppressing damage to the mounting table.

[Configuration of plasma processing apparatus]
FIG. 1 is a schematic cross-sectional view showing the configuration of a plasma processing apparatus 10 according to one embodiment. The plasma processing apparatus 10 has a processing container 1 that is airtight and electrically grounded. The processing container 1 is cylindrical and made of, for example, aluminum. The processing vessel 1 defines a processing space in which plasma is generated. In the processing chamber 1, a mounting table 2 is provided for horizontally supporting a semiconductor wafer (hereinafter simply referred to as "wafer") W, which is a substrate (work-piece). The mounting table 2 includes a substrate (base) 2 a and an electrostatic chuck (ESC: Electrostatic chuck) 6 . The base material 2a is made of a conductive metal such as aluminum, and functions as a lower electrode. The electrostatic chuck 6 has a function of electrostatically attracting the wafer W. As shown in FIG. The electrostatic chuck 6 is arranged on the upper surface of the base material 2a. The mounting table 2 is supported by the support table 4 . The support base 4 is supported by a support member 3 made of, for example, quartz.

A focus ring 5 made of, for example, single-crystal silicon is provided on the outer periphery of the mounting table 2 . Specifically, the focus ring 5 is formed in an annular shape, and is arranged on the upper surface of the base material 2a so as to surround the outer periphery of the mounting surface (upper surface of the electrostatic chuck 6) of the mounting table 2. As shown in FIG. Furthermore, a cylindrical inner wall member 3a made of quartz or the like is provided in the processing container 1 so as to surround the mounting table 2 and the support table 4 .

A first RF power supply 10a is connected to the substrate 2a through a first matching box 11a, and a second RF power supply 10b is connected through a second matching box 11b. The first RF power supply 10a is for plasma generation, and is configured to supply high-frequency power of a predetermined frequency to the substrate 2a of the mounting table 2 from the first RF power supply 10a. The second RF power supply 10b is for attracting ions (bias), and from this second RF power supply 10b, high-frequency power with a predetermined frequency lower than that of the first RF power supply 10a is applied to the base of the mounting table 2. It is configured to be supplied to the material 2a. Thus, the mounting table 2 is configured to be able to apply voltage. On the other hand, a shower head 16 functioning as an upper electrode is provided above the mounting table 2 so as to face the mounting table 2 in parallel. The shower head 16 and the mounting table 2 function as a pair of electrodes (upper electrode and lower electrode).

The electrostatic chuck 6 has a disk shape with a flat upper surface, and the upper surface serves as a mounting surface 6e on which the wafer W is mounted. The electrostatic chuck 6 is constructed by interposing an electrode 6a between the insulators 6b, and a DC power source 12 is connected to the electrode 6a. When a DC voltage is applied to the electrode 6a from the DC power source 12, the wafer W is attracted by Coulomb force.

In this embodiment, the diameter of the mounting surface 6e is slightly smaller than the diameter of the wafer W as an example.

A temperature control medium channel 2d is formed inside the mounting table 2, and an inlet pipe 2b and an outlet pipe 2c are connected to the temperature control medium channel 2d. By circulating an appropriate temperature control medium such as cooling water in the temperature control medium flow path 2d, the mounting table 2 can be controlled at a predetermined temperature. Further, a gas supply pipe 30 for supplying cold heat transfer gas (backside gas) such as helium gas is provided to the rear surface of the wafer W so as to pass through the mounting table 2 and the like. , is connected to a gas supply source (not shown). With these configurations, the wafer W attracted and held on the upper surface of the mounting table 2 by the electrostatic chuck 6 is controlled to a predetermined temperature.

The mounting table 2 is provided with a plurality of, for example, three pin through holes 200 (only one is shown in FIG. 1). are arranged. The lifter pins 61 are connected to the lifting mechanism 62 . The elevating mechanism 62 elevates the lifter pins 61 so that the lifter pins 61 can freely appear and retract with respect to the mounting surface 6 e of the mounting table 2 . When the lifter pins 61 are lifted, the tips of the lifter pins 61 protrude from the mounting surface 6e of the mounting table 2, and the wafer W is held above the mounting surface 6e of the mounting table 2. FIG. On the other hand, when the lifter pins 61 are lowered, the tips of the lifter pins 61 are accommodated in the pin through holes 200 and the wafer W is mounted on the mounting surface 6 e of the mounting table 2 . In this way, the lifting mechanism 62 lifts and lowers the wafer W with respect to the mounting surface 6 e of the mounting table 2 with the lifter pins 61 . Further, the lifting mechanism 62 holds the wafer W above the mounting surface 6 e of the mounting table 2 with the lifter pins 61 in a state where the lifter pins 61 are raised.

The shower head 16 described above is provided on the top wall portion of the processing vessel 1 . The shower head 16 includes a main body 16 a and an upper top plate 16 b that serves as an electrode plate, and is supported above the processing vessel 1 via an insulating member 95 . The body portion 16a is made of a conductive material such as aluminum whose surface is anodized, and is configured to detachably support the upper top plate 16b on the lower portion thereof.

A gas diffusion chamber 16c is provided inside the body portion 16a. Further, the main body portion 16a has a large number of gas communication holes 16d formed in the bottom thereof so as to be positioned below the gas diffusion chamber 16c. Further, the upper top plate 16b is provided with a gas introduction hole 16e that penetrates the upper top plate 16b in the thickness direction so as to overlap the above-described gas flow hole 16d. With such a configuration, the processing gas supplied to the gas diffusion chamber 16c is dispersed and supplied into the processing chamber 1 through the gas communication hole 16d and the gas introduction hole 16e in the form of a shower.

A gas introduction port 16g for introducing a processing gas into the gas diffusion chamber 16c is formed in the body portion 16a. One end of the gas supply pipe 15a is connected to the gas introduction port 16g. A gas supply source (gas supply unit) 15 for supplying a processing gas is connected to the other end of the gas supply pipe 15a. The gas supply pipe 15a is provided with a mass flow controller (MFC) 15b and an on-off valve V2 in order from the upstream side. A processing gas for plasma etching is supplied from the gas supply source 15 to the gas diffusion chamber 16c through the gas supply pipe 15a. A processing gas is supplied from the gas diffusion chamber 16c into the processing container 1 in a shower-like manner through the gas communication hole 16d and the gas introduction hole 16e.

A variable DC power supply 72 is electrically connected to the shower head 16 as the upper electrode described above via a low-pass filter (LPF) 71 . The variable DC power supply 72 is configured so that power supply can be turned on/off by an on/off switch 73 . The current/voltage of the variable DC power supply 72 and the on/off of the on/off switch 73 are controlled by the controller 100, which will be described later. As will be described later, when high-frequency waves are applied to the mounting table 2 from the first RF power supply 10a and the second RF power supply 10b and plasma is generated in the processing space, the control unit 100 turns on the power supply as necessary. - The off switch 73 is turned on. Thereby, a predetermined DC voltage is applied to the shower head 16 as the upper electrode.

A cylindrical ground conductor 1a is provided to extend from the side wall of the processing container 1 above the height position of the shower head 16 . The cylindrical ground conductor 1a has a top wall on its top.

An exhaust port 81 is formed at the bottom of the processing container 1 . A first exhaust device 83 is connected to the exhaust port 81 via an exhaust pipe 82 . The first evacuation device 83 has a vacuum pump, and is configured to be able to reduce the pressure inside the processing container 1 to a predetermined degree of vacuum by operating the vacuum pump. On the other hand, a loading/unloading port 84 for the wafer W is provided on the side wall inside the processing container 1 , and the loading/unloading port 84 is provided with a gate valve 85 for opening and closing the loading/unloading port 84 .

A deposit shield 86 is provided along the inner wall surface inside the side portion of the processing container 1 . The deposit shield 86 prevents etching by-products (depot) from adhering to the processing chamber 1 . A conductive member (GND block) 89 connected to the ground so as to control the potential is provided at a position of the deposition shield 86 substantially at the same height as the wafer W, thereby preventing abnormal discharge. A deposit shield 87 extending along the inner wall member 3 a is provided at the lower end of the deposit shield 86 . The deposit shields 86 and 87 are detachable.

The operation of the plasma processing apparatus 10 configured as described above is centrally controlled by the control unit 100 . The control unit 100 includes a process controller 101 having a CPU and controlling each unit of the plasma processing apparatus 10 , a user interface 102 , and a storage unit 103 .

The user interface 102 includes a keyboard for inputting commands for the process manager to manage the plasma processing apparatus 10, a display for visualizing and displaying the operating status of the plasma processing apparatus 10, and the like.

The storage unit 103 stores a control program (software) for realizing various processes executed in the plasma processing apparatus 10 under the control of the process controller 101, a recipe storing process condition data, and the like. Then, if necessary, an arbitrary recipe is called from the storage unit 103 by an instruction from the user interface 102 or the like, and is executed by the process controller 101 . is processed. Recipes such as control programs and processing condition data can be stored in computer-readable computer storage media (for example, hard disks, CDs, flexible disks, semiconductor memories, etc.). be. Also, recipes such as control programs and processing condition data can be transmitted from another device, for example, via a dedicated line, and used online.

[Cleaning process]
Next, details of the cleaning process performed by the plasma processing apparatus 10 according to the embodiment will be described with reference to FIG. FIG. 2 is a flowchart showing an example of cleaning processing. The cleaning process illustrated in FIG. 2 is realized by the plasma processing apparatus 10 operating mainly under the control of the controller 100 .

The wafer W used in the cleaning process may be a product wafer or a dummy wafer.

First, a wafer W is loaded into the processing container 1 (S100). In step S100, the gate valve 85 is opened, and the wafer W is loaded into the processing container 1 by a transfer arm (not shown) and placed on the mounting surface 6e of the mounting table 2. FIG. Specifically, in step S100, the lifter pins 61 are in an elevated state, and the wafer W is transferred to the lifter pins 61 from the transfer arm. After that, the lifter pins 61 descend to transfer the wafer W from the lifter pins 61 to the mounting surface 6e. After that, the gate valve 85 is closed.

Next, the lifter pins 61 are raised (pinned up) to separate the wafer W from the mounting surface 6e (S101). Information on the separation distance between wafer W and mounting surface 6 e is pre-stored, for example, in storage unit 103 , and control unit 100 raises lifter pins 61 according to the information stored in storage unit 103 .

Here, an example is shown in which the wafer W is once mounted on the mounting surface 6e in step S101, and then the wafer W is raised to the set separation distance in step S101. Not limited to this example, for example, after receiving the wafer W using the lifter pins 61 in step S101, by lowering the lifter pins 61, the separation distance between the wafer W and the mounting surface 6e is the preset distance. The wafer W may be arranged at a height position where . The separation distance between the wafer W and the mounting surface 6e in step S101 is at least smaller than the distance between the mounting surface 6e and the lifter pins 61 at the height position where the wafer W is received in step S100.

Next, after the inside of the processing container 1 is depressurized to a predetermined degree of vacuum by the first exhaust device 83, the reaction gas is supplied from the gas supply source 15 into the processing container 1 through the gas supply pipe 15a (S102). . In this embodiment, when the deposit to be cleaned is a CF-based polymer, the reaction gas supplied from the gas supply source 15 is O ₂ gas. Also, the reactive gas is not limited to _O2 gas, and may be other oxygen-containing gases such as CO gas, _CO2 gas, _O3 gas, and the like. Further, when the deposit contains silicon or metal in addition to the CF-based polymer, a halogen-containing gas, for example, may be added to the reaction gas O ₂ gas. The halogen-containing gas is, for example, a fluorine-based gas such as _CF4 gas, _NF3 gas. The halogen-containing gas may also be a chlorine-based gas such as _Cl2 gas or a bromine-based gas such as HBr gas. Thus, in the cleaning process, an oxygen-containing gas is used as the reaction gas.

Next, high-frequency power is supplied to the mounting table 2, which is the lower electrode (S103). In step S<b>103 , the control unit 100 controls the first RF power supply 10 a and the second RF power supply 10 b to generate high-frequency power, thereby supplying the high-frequency power to the substrate 2 a of the mounting table 2 . Also, the controller 100 applies the DC power supplied from the variable DC power supply 72 to the shower head 16 by turning on the on/off switch 73 . Thereby, plasma of the oxygen-containing gas is generated in the processing container 1 . The frequency of the high-frequency power generated by the first RF power supply 10a and the second RF power supply 10b is not particularly limited. Also, here, an example in which the plasma processing apparatus 10 includes the first RF power supply 10a and the second RF power supply 10b is shown, but the plasma processing apparatus 10 does not necessarily include the second RF power supply 10b. don't need it.

Next, the control unit 100 determines whether or not a preset processing time has elapsed since the supply of high-frequency power was started in step S103 (S104). If the set processing time has not elapsed (S104: No), the processing of step S104 is executed again.

On the other hand, when the set processing time has passed (S104: Yes), the supply of high-frequency power to the mounting table 2 is stopped (S105). Also, the supply of the reaction gas into the processing container 1 is stopped (S106).

After the reaction gas in the processing container 1 is exhausted, the gate valve 85 is opened, and the wafer W is unloaded from the processing container 1 by a transfer arm (not shown) (S107). Specifically, the control unit 100 raises the lifter pins 61 to place the wafer W at the transfer position, and transfers the wafer W supported by the lifter pins 61 to the transfer arm. This completes the cleaning method shown in this flow chart.

[Regarding Plasma Generated in Cleaning Process]
FIG. 3 is a diagram showing an example of the distribution of plasma generated when high-frequency power is supplied while the wafer W is mounted on the mounting table 2. As shown in FIG. FIG. 4 is a diagram showing an example of distribution of plasma generated when high-frequency power is supplied while the wafer W is separated from the mounting table 2. As shown in FIG.

As shown in FIG. 3, when high-frequency power is supplied to the mounting table 2 from the first RF power supply 10a while the wafer W is mounted on the mounting table 2, the plasma P is generated under reduced pressure between the wafer W and the shower head 16. It is evenly distributed in the in-plane direction of the wafer W in the space.

In contrast, the inventor of the present application separates the wafer W from the mounting surface 6e and appropriately sets the separation distance so that the plasma P is formed in the outer peripheral portion of the mounting table 2 as shown in FIG. It was found that it can be unevenly distributed in the periphery.

This mechanism can be explained, for example, as follows. That is, when the wafer W and the mounting surface 6e are separated from each other, a vacuum space is also formed between the wafer W and the mounting surface 6e. This depressurized space can be regarded as a capacitor provided on the high-frequency power path from the first RF power source 10 a to the ground connected to the shower head 16 via the mounting table 2 . This capacitor forms part of the combined impedance on the high frequency power path from the first RF power supply 10a to ground.

Here, the path of the high-frequency power from the mounting table 2 to the shower head 16 is divided into a path immediately above the central portion of the mounting table 2 and a path above the outer peripheral portion of the mounting table 2 (hereinafter referred to as "central path"). described as "outer path"). As shown in FIG. 3, when the wafer W is mounted on the mounting table 2, the combined impedance per unit area on the mounting surface 6e is substantially the same between the central path and the outer peripheral path. On the other hand, as shown in FIG. 4, when the wafer W and the mounting surface 6e are separated from each other, the route in the outer peripheral portion is divided into a route through the wafer W and a route outside the wafer W not through the wafer W. It becomes a parallel route. The path through the wafer W is a path through a capacitor formed in the reduced pressure space between the wafer W and the mounting surface 6e, and the path not through the wafer W is a path not through the capacitor. be.

Therefore, the combined impedance per unit area formed by the two parallel high-frequency power paths around the outer periphery of the mounting surface 6e is higher than the combined impedance per unit area formed directly above the central portion of the mounting surface 6e. also lower.

The high-frequency power flows intensively around the periphery of the mounting surface 6e where the composite impedance is relatively low. As a result, the density of the plasma P around the outer periphery of the mounting surface 6e becomes higher than the density of the plasma P at the center of the mounting surface 6e, and a ring-shaped plasma P is formed around the outer periphery of the mounting surface 6e. is formed.

In the cleaning process according to the embodiment, by using the plasma P unevenly distributed around the outer periphery of the mounting table 2, deposits deposited on the outer periphery of the mounting table 2 can be efficiently removed. That is, according to the cleaning process according to the embodiment, the plasma P concentrates around the outer periphery of the mounting table 2, so that the ability to remove deposits deposited on the outer periphery of the mounting table 2 can be enhanced. Therefore, deposits deposited on the outer peripheral portion of the mounting table 2 can be reliably removed in a short period of time. In addition, since the density of the plasma P is relatively low in the portion other than the outer peripheral portion, it is possible to suppress the plasma P from damaging the portion of the mounting table 2 other than the outer peripheral portion.

As described above, according to the cleaning process according to the embodiment, it is possible to remove deposits accumulated on the outer peripheral portion of the mounting table 2 while suppressing damage to the mounting table 2 .

Further, according to the cleaning process according to the embodiment, deposits accumulated on the outer peripheral portion of the mounting table 2 can be removed without preparing an electrode having a special structure that generates local plasma in the outer peripheral portion of the mounting table. It can be removed efficiently.

Of the deposits deposited on the outer peripheral portion of the mounting table 2, the deposits of the CF-based polymer can be removed by plasma of an oxygen-containing gas such as _O2 gas. Also, Si-based or metal-based deposits can be removed by plasma of a halogen-containing gas such as _CF4 gas, _NF3 gas, _Cl2 gas, HBr gas. Moreover, mixed deposits of CF-based polymer and at least one of Si-based and metal-based materials can be removed by plasma of a mixed gas of an oxygen-containing gas and a halogen-containing gas. The CF-based polymer deposits can also be removed with a hydrogen-containing gas such as _H2 gas or a nitrogen-containing gas such as _N2 . Also, a rare gas such as argon gas or helium gas may be added.

The inventors of the present application have found that when a wafer W coated with a resist film, which is an organic film similar to the CF-based polymer deposit, is treated with O ₂ gas plasma as a substitute for the CF-based polymer deposit, the upper surface of the wafer W is An experiment was conducted to examine the etching rate of the resist film at each position. The results of this experiment are shown in FIG. FIG. 5 is a graph showing the relationship between the separation distance between the wafer W and the mounting surface 6e and the etching rate of the resist film at each position on the upper surface of the wafer W. As shown in FIG.

Further, the inventor of the present application conducted the same experiment as described above with the surface of the wafer W coated with the resist film facing the mounting surface 6e. That is, an experiment was conducted to examine the etching rate of the resist film at each position on the lower surface of the wafer W (the surface coated with the resist film) when the wafer W was processed by O ₂ gas plasma. The results of this experiment are shown in FIG. FIG. 6 is a graph showing the relationship between the separation distance between the wafer W and the mounting surface 6e and the etching rate of the resist film at each position on the lower surface of the wafer W. As shown in FIG.

The processing conditions for the experimental results shown in FIGS. 5 and 6 are as follows.
Pressure in processing container 1: 100 to 800 mT
RF power: ~1000W
Gas type and flow rate: O ₂ gas Diameter of wafer W: 300 mm
Processing time: 30 sec

5 and 6 indicate the measurement position of the etching rate by the distance from the center of the wafer W. FIG. For example, the center of wafer W is 0 mm.

As shown in FIG. 5, when the separation distance is less than 2.3 mm, 0 mm which is the center of the wafer W (indicated by square plots in the figure) and 100 mm relatively close to the center (indicated by circle plots in the figure). (indicated by ) increases the etching rate. From this result, it can be seen that the plasma spreads near the center of the upper surface of the wafer W when the separation distance is smaller than 2.3 mm.

Also, as shown in FIG. 6, when the separation distance is smaller than 2.3 mm, 148 mm which is the outer peripheral portion of the wafer W (represented by rhombic plots in the figure) and 145 mm which is relatively close to the outer peripheral portion (represented by the reversed indicated by triangular plots) are hardly etched. The mounting surface 6e of the mounting table 2 has substantially the same diameter as the wafer W (slightly smaller). Therefore, from this result, it can be seen that plasma is hardly generated between the wafer W and the mounting surface 6e when the separation distance is smaller than 2.3 mm.

On the other hand, as shown in FIG. 6, when the separation distance is greater than 5 mm, the etching rate increases at 0 mm and 100 mm near the center of the wafer W. From this result, it can be seen that when the separation distance is larger than 5 mm, the plasma spreads near the center of the lower surface of the wafer W, in other words, near the center of the mounting surface 6e.

From the above results, it is preferable that the separation distance between the wafer W and the mounting surface 6e is 2.3 mm or more and 5 mm or less. By setting the separation distance within such a range, the plasma can be appropriately unevenly distributed around the outer peripheral portion of the mounting table 2 . That is, a ring-shaped plasma can be generated around the outer peripheral portion of the mounting table 2 while protecting the central portion of the mounting table 2 from the plasma.

Further, as shown in FIG. 6, the etching rate at 148 mm and 145 mm near the outer periphery of the wafer W becomes maximum when the separation distance is 3 mm. From this result, the separation distance between the wafer W and the mounting surface 6e is preferably 2.3 mm or more and 3.5 mm or less, more preferably 2.3 mm or more and 3 mm or less. By setting the separation distance within such a range, the deposits accumulated on the outer peripheral portion of the mounting table 2 can be reliably removed in a short time.

As described above, the separation distance between the wafer W and the mounting surface 6e set in this embodiment is small. At least, the separation distance between the wafer W and the mounting surface 6e is smaller than the thickness of the plasma sheath generated between the wafer W and the showerhead 16 in the cleaning process.

In order to examine the state of the plasma outside the wafer W, the inventor of the present application attached a chip-shaped wafer W coated with a resist film onto the focus ring 5, and measured each position on the top surface of the chip-shaped wafer W. An experiment was conducted to examine the etching rate of the resist film. The results of this experiment are shown in FIG. FIG. 7 is a graph showing the relationship between the distance between the wafer W and the mounting surface 6e and the etching rate of the resist film at each position on the focus ring 5. As shown in FIG. The processing conditions for the experimental results shown in FIG. 7 are the same as those for the experimental results shown in FIGS.

In the graph shown in FIG. 7, the horizontal axis indicates the focus ring position. The focus ring position is the position where the etching rate is measured on the focus ring 5 and is indicated by the distance from the inner edge of the upper surface of the focus ring 5 . For example, the inner edge of the top surface of the focus ring 5 closest to the mounting surface 6e of the mounting table 2 is 0 mm. In the graph shown in FIG. 7, the horizontal axis indicates the distance from the mounting surface 6e, and plots up to 15 mm in FIG.

In the graph shown in FIG. 7, the vertical axis indicates the etching rate of the resist film on the focus ring 5. In FIG. Specifically, the etching rate of a predetermined material placed on the upper surface of the focus ring 5 is shown as the etching rate of the focus ring.

As shown in FIG. 7, when the separation distance between the wafer W and the mounting surface 6e is less than 2.3 mm (indicated by triangular plots in the figure) and 1 mm (indicated by square plots in the figure), , the etching rate of the resist film on the focus ring 5 is low. On the other hand, when the separation distance is 2.5 mm, which is 2.3 mm or more (indicated by plotted circles in the drawing), the etching rate of the resist film on the focus ring 5 increases compared to 0 mm and 1 mm. , and a high value was shown in the inner peripheral portion near the mounting table 2 .

From this result, by setting the separation distance between the wafer W and the mounting surface 6e to 2.3 mm or more, the peripheral portion of the mounting surface 6e, specifically, the outer peripheral portion of the mounting surface 6e and the focus ring 5 can be separated. It can be seen that plasma with a high plasma density is generated in the region including the inner periphery of the upper surface.

Also, the etching rate of the resist film on the focus ring 5 when the separation distance is 2.5 mm is highest at the inner peripheral portion of the focus ring 5 near the mounting table 2 and decreases with increasing distance from the mounting table 2 .

From this result, it can be seen that the density of plasma generated in the cleaning process is higher in the inner peripheral portion of the focus ring 5 than in the outer peripheral portion. That is, by setting the separation distance to 2.3 mm or more, the focus ring 5 can be placed around the outer periphery of the mounting surface 6e, specifically, including the outer periphery of the mounting surface 6e and the inner periphery of the upper surface of the focus ring 5. Plasma can be generated in a localized area that does not include the outer periphery of the top surface of the .

[Modification]
In the cleaning process described above, the plasma processing apparatus 10 may clean structures other than the mounting table 2 including the inner wall of the processing chamber 1 .

For example, the plasma processing apparatus 10 generates plasma in the processing container 1 with the wafer W placed on the mounting surface 6e, and deposits on the inner wall of the processing container 1 using the generated plasma. A treatment to remove deposits may be performed.

This process may be performed, for example, after the wafer W is loaded into the processing container 1 and mounted on the mounting surface 6e in step S100, and before the lifter pins 61 are raised in step S101. In this case, before lifting the lifter pins 61 in step S101, it is preferable to stop the supply of the high-frequency power and the reaction gas to extinguish the plasma. This is because if the lifter pins 61 are lifted while plasma is generated, there is a risk that the ring-shaped plasma will not be properly formed around the outer periphery of the mounting table 2 .

Also, this process may be performed, for example, after the processing time set in step S104 has elapsed. In this case, after the processing time set in step S104 has elapsed, the lifter pins 61 are lowered to mount the wafer W on the mounting surface 6e, and the plasma processing can be continued in this state.

By performing the cleaning process while the wafer W is mounted on the mounting table 2 in this way, it is possible to protect the mounting surface 6e with the wafer W and remove deposits accumulated on the inner wall of the processing vessel 1 and the like. can be done.

Further, the plasma processing apparatus 10 removes deposits accumulated in the processing container 1 using the generated plasma by generating plasma in the processing container 1 in a state in which no wafer W is accommodated in the processing container 1 . You may perform processing to do.

This process may be performed, for example, before the wafer W is loaded into the processing container 1 in step S100. Also in this case, it is preferable to stop the supply of the high-frequency power and the reactive gas to extinguish the plasma before the wafer W is loaded into the processing container 1 in step S100. Also, this process may be performed after the wafer W is unloaded from the processing container 1 in step S107.

In this way, by performing the cleaning process in a state in which no wafer W is housed in the processing container 1, the deposits accumulated on the outer peripheral portion of the mounting surface 6e are mainly removed while the mounting surface 6e is cleaned. Deposits deposited at locations other than the perimeter can also be removed. That is, the entire mounting surface 6e can be cleaned.

As described above, the cleaning method according to the present embodiment includes a mounting table (for example, mounting table 2) on which a substrate (for example, wafer W) is mounted, and an elevating mechanism for moving the substrate up and down with respect to the mounting table. A method of cleaning a mounting table in a plasma processing apparatus (plasma processing apparatus 10 as an example) including (elevating mechanism 62 as an example) and a high frequency power supply (first RF power supply 10a as an example) connected to the mounting table is. The cleaning method according to this embodiment includes a separating step and a removing step. In the separating step, the mounting table and the substrate are separated using an elevating mechanism. In the removing step, after the step of isolating, plasma is generated by supplying high-frequency power from a high-frequency power supply to the mounting table to remove the deposit deposited on the mounting table. In the separation step, the separation distance between the mounting table and the substrate is set so that the combined impedance formed around the periphery of the mounting table is lower than the combined impedance formed directly above the central portion of the mounting table. be done.

According to the cleaning method according to the present embodiment, the plasma can be unevenly distributed around the outer periphery of the mounting table, so that the deposits accumulated on the outer periphery of the mounting table can be removed while suppressing damage to the mounting table. be able to.

The separation distance between the mounting table and the substrate is smaller than the thickness of the sheath of plasma generated in the removing process (for example, plasma generated between wafer W and showerhead 16). That is, in the cleaning method according to this embodiment, the separation distance between the mounting table and the substrate is small.

Specifically, the separation distance between the mounting table and the substrate is 2.3 mm or more and 5 mm or less. By setting the separation distance within such a range, the plasma can be appropriately unevenly distributed around the outer periphery of the mounting table. That is, it is possible to generate a ring-shaped plasma around the outer peripheral portion of the mounting table while protecting the central portion of the mounting table from the plasma.

The distance between the mounting table and the substrate is preferably 2.3 mm or more and 3.5 mm or less, more preferably 2.3 mm or more and 3 mm or less. By setting the separation distance within such a range, the deposits accumulated on the outer peripheral portion of the mounting table 2 can be reliably removed in a short time.

The density of plasma generated in the removing step is higher around the periphery of the substrate than at the center of the substrate. Therefore, it is possible to remove deposits deposited on the outer peripheral portion of the mounting table while suppressing damage to the mounting table.

The plasma processing apparatus includes a ring member (for example, focus ring 5) surrounding the outer circumference of the mounting surface of the mounting table. Further, the density of plasma generated in the removing step is higher in the inner peripheral portion of the ring member than in the outer peripheral portion of the ring member. That is, according to the cleaning method according to the present embodiment, the peripheral portion of the mounting table, specifically, the outer peripheral portion of the mounting table and the inner peripheral portion of the ring member are included, but the outer peripheral portion of the ring member is not included. A ring-shaped plasma can be formed in a localized area.

The removing step generates plasma of an oxygen-containing gas (for example, O ₂ gas or a reaction gas obtained by adding halogen gas to O ₂ gas). As a result, carbon-based deposits deposited on the outer peripheral portion of the mounting table can be preferably removed.

A plasma processing apparatus includes a processing container (processing container 1 as an example) that accommodates a mounting table. Further, in the cleaning method according to the embodiment, the substrate is mounted on the mounting table before the separating step (before step S101 as an example) or after the removing step (after step S104 as an example). and removing deposits deposited on the processing vessel using plasma. As a result, it is possible to remove deposits adhering to the inner wall of the processing chamber and the like while protecting the mounting table with the substrate.

A plasma processing apparatus includes a processing container (processing container 1 as an example) that accommodates a mounting table. Further, in the cleaning method according to the embodiment, the substrate is accommodated in the processing container before the separating step (before step S100 as an example) or after the removing step (after step S107 as an example). removing deposits deposited in the processing container using plasma in the absence of the plasma; As a result, the entire mounting surface of the mounting table can be cleaned.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. Indeed, the above-described embodiments may be embodied in many different forms. Also, the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

Further, the following additional remarks are disclosed regarding the above embodiments.

(Appendix 1)
A cleaning method in a plasma processing apparatus, comprising:
The plasma processing apparatus is
a processing vessel;
a substrate mounting table provided in the processing container;
a substrate lifting mechanism including lifter pins that support the substrate;
The cleaning method is
(a) Plasma is generated in the processing container after the substrate is plasma-processed in the processing container and the substrate and the dummy substrate are not accommodated in the processing container, and the plasma is deposited in the processing container. removing deposits;
(b) controlling the substrate lifting mechanism to position the tips of the lifter pins at a first position, and receiving the dummy substrate loaded into the processing container at the first position;
(c) controlling the substrate lifting mechanism to position the tips of the lifter pins at a second position above the substrate mounting table and lower than the first position;
(d) after the step (c), generating plasma in the processing container to remove deposits deposited on the outer peripheral portion of the substrate mounting table;
A cleaning method.
(Appendix 2)
The cleaning method according to Appendix 1, wherein the step (b) is performed after the step (a).
(Appendix 3)
3. The cleaning method according to appendix 1 or 2, wherein the step (a) is performed after the step (b), the step (c) and the step (d).
(Appendix 4)
(e) after the step (b), lowering the lifter pins to mount the dummy substrate on the substrate mounting table;
4. The cleaning method according to any one of Appendices 1 to 3, wherein in the step (c), after the step (e), the lifter pins are raised to position the dummy substrate at the second position.
(Appendix 5)
(f) after the step (e) and before the step (c), plasma is generated in the processing container while the dummy substrate is mounted on the mounting surface of the substrate mounting table; 5. The cleaning method according to appendix 4, comprising the step of cleaning the processing container with a
(Appendix 6)
(g) after the step (d), cleaning the processing container by generating plasma in the processing container with the dummy substrate mounted on the mounting surface of the substrate mounting table; , the cleaning method according to any one of Appendices 1 to 5.
(Appendix 7)
7. The cleaning method according to any one of Appendices 1 to 6, wherein in the step (d), a ring-shaped plasma is generated around the outer periphery of the substrate mounting table.
(Appendix 8)
8. The separation distance between the mounting surface of the substrate mounting table and the surface of the dummy substrate facing the mounting surface is smaller than the thickness of the sheath of the plasma generated in the step (d). A cleaning method according to any one of the above.
(Appendix 9)
9. The cleaning method according to any one of appendices 1 to 8, wherein a separation distance between the mounting surface of the substrate mounting table and the surface of the dummy substrate facing the mounting surface is 2.3 mm or more and 5 mm or less. .
(Appendix 10)
The cleaning method according to appendix 9, wherein a separation distance between the mounting surface of the substrate mounting table and the surface of the dummy substrate facing the mounting surface is 2.3 mm or more and 3.5 mm or less.
(Appendix 11)
The cleaning method according to appendix 9, wherein a separation distance between the mounting surface of the substrate mounting table and the surface of the dummy substrate facing the mounting surface is 2.3 mm or more and 3 mm or less.
(Appendix 12)
12. The cleaning method according to any one of Appendices 1 to 11, wherein the density of plasma generated in the step (d) is higher around the periphery of the dummy substrate than at the center of the dummy substrate.
(Appendix 13)
The plasma processing apparatus includes a ring member surrounding the outer circumference of the mounting surface of the substrate mounting table,
13. The cleaning method according to claim 12, wherein the density of the plasma generated in the step (d) is higher at the inner peripheral portion of the ring member than at the outer peripheral portion of the ring member.
(Appendix 14)
14. The cleaning method according to any one of appendices 1 to 13, wherein plasma of an oxygen-containing gas is generated in the step (d).
(Appendix 15)
15. The cleaning method according to any one of Appendices 1 to 14, wherein in the step (d), high-frequency power for generating plasma is supplied to the substrate mounting table.
(Appendix 16)
16. The cleaning method according to any one of Appendices 1 to 15, wherein in the step (d), bias power is supplied to the substrate mounting table.
(Appendix 17)
A cleaning method in a plasma processing apparatus, comprising:
The plasma processing apparatus is
a processing vessel;
a substrate mounting table provided in the processing container;
a substrate lifting mechanism,
The cleaning method is
a first step of generating plasma in the processing container after the plasma processing of the substrate and cleaning the inside of the processing container in a state in which the substrate and the dummy substrate are not accommodated in the processing container;
a second step of cleaning the inside of the processing container by generating plasma in the processing container with the dummy substrate mounted on the substrate mounting table;
a third step of positioning the dummy substrate above the substrate mounting table by the substrate elevating mechanism, generating plasma in the processing container, and cleaning the inside of the processing container;
A cleaning method.
(Appendix 18)
18. The cleaning method according to Appendix 17, wherein the first step, the second step, and the third step are performed in this order.
(Appendix 19)
19. The cleaning method according to appendix 17 or 18, wherein the first step is performed after the second step and the third step.
(Appendix 20)
20. The cleaning method according to any one of appendices 17 to 19, wherein in the first step, the second step, and the third step, high-frequency power for generating plasma is supplied to the substrate mounting table.
(Appendix 21)
21. The cleaning method according to any one of appendices 17 to 20, wherein in the third step, bias power is supplied to the substrate mounting table.
(Appendix 22)
a processing vessel;
a substrate mounting table provided in the processing container;
a substrate lifting mechanism including lifter pins for supporting the substrate;
a control unit;
with
The control unit
(a) Plasma is generated in the processing container after the substrate is plasma-processed in the processing container and the substrate and the dummy substrate are not accommodated in the processing container, and the plasma is deposited in the processing container. a process to remove deposits;
(b) a process of controlling the substrate lifting mechanism to position the tips of the lifter pins at a first position and receiving the dummy substrate carried into the processing container at the first position;
(c) a process of controlling the substrate lifting mechanism to position the tips of the lifter pins at a second position above the substrate mounting table and lower than the first position;
(d) after the process (c), plasma is generated in the processing container to remove deposits deposited on the outer periphery of the substrate mounting table;
A plasma processing apparatus configured to perform
(Appendix 23)
The control unit
23. The plasma processing apparatus of Claim 22, configured to perform said process (b) after said process (a).
(Appendix 24)
The control unit
24. The plasma processing apparatus of clause 22 or 23, wherein the plasma processing apparatus is configured to perform said process (a) after said process (b), said process (c) and said process (d).
(Appendix 25)
The control unit
(e) a process of lowering the lifter pins to mount the dummy substrate on the substrate mounting table after the process (b), and performing the process after the process (e). 25. The plasma processing apparatus according to any one of appendices 22 to 24, wherein in (c), the lifter pins are raised to position the dummy substrate at the second position.
(Appendix 26)
The control unit
(f) after the process (e) and before the process (c), plasma is generated in the processing container while the dummy substrate is mounted on the mounting surface of the substrate mounting table; 26. The plasma processing apparatus of Clause 25, wherein the plasma processing apparatus is configured to:
(Appendix 27)
The control unit
(g) performing a process of generating plasma in the processing container to clean the processing container with the dummy substrate mounted on the mounting surface of the substrate mounting table after the processing (d); 27. The plasma processing apparatus according to any one of appendices 22-26, wherein the plasma processing apparatus is configured to:
(Appendix 28)
28. The plasma processing apparatus according to any one of appendices 22 to 27, wherein in the process (d), a ring-shaped plasma is generated around the outer periphery of the substrate mounting table.
(Appendix 29)
29. The plasma processing according to any one of Appendices 22 to 28, wherein a separation distance between the mounting surface of the substrate mounting table and the surface of the dummy substrate facing the mounting surface is 2.3 mm or more and 5 mm or less. Device.
(Appendix 30)
29. The plasma processing apparatus according to any one of appendices 22 to 29, wherein the density of plasma generated in the process (d) is higher around the periphery of the dummy substrate than at the center of the dummy substrate.
(Appendix 31)
A ring member surrounding the outer periphery of the mounting surface of the substrate mounting table,
31. The plasma processing apparatus according to appendix 30, wherein the density of plasma generated in the process (d) is higher in the inner peripheral portion of the ring member than in the outer peripheral portion of the ring member.
(Appendix 32)
The control unit
32. The plasma processing apparatus according to any one of appendices 22 to 31, wherein in the treatment (d), the plasma is configured to generate plasma of an oxygen-containing gas.
(Appendix 33)
The control unit
33. The plasma processing apparatus according to any one of appendices 22 to 32, wherein in the process (d), bias power is supplied to the substrate mounting table.
(Appendix 34)
a processing vessel;
a substrate mounting table provided in the processing container;
a substrate lifting mechanism;
a control unit;
with
The control unit
a first process of generating plasma in the processing container and cleaning the inside of the processing container after the plasma processing of the substrate, in a state in which the substrate and the dummy substrate are not accommodated in the processing container;
a second process of cleaning the inside of the processing container by generating plasma in the processing container with the dummy substrate mounted on the substrate mounting table;
a third process of positioning a dummy substrate above the substrate mounting table by the substrate elevating mechanism, generating plasma in the processing container, and cleaning the inside of the processing container;
A plasma processing apparatus configured to perform
(Appendix 35)
The control unit
35. The plasma processing apparatus according to appendix 34, configured to perform the first process, the second process, and the third process in this order.
(Appendix 36)
The control unit
36. The plasma processing apparatus of clause 34 or 35, configured to perform the first process after the second process and the third process.
(Appendix 37)
The control unit
37. The method according to any one of appendices 34 to 36, wherein in the first treatment, the second treatment, and the third treatment, high-frequency power for generating plasma is supplied to the substrate mounting table. Plasma processing equipment.
(Appendix 38)
The control unit
38. The plasma processing apparatus according to any one of appendices 34 to 37, wherein in the third process, bias power is supplied to the substrate mounting table.

P Plasma W Wafer 1 Processing container 2 Mounting table 6 Electrostatic chuck 6a Electrode 10 Plasma processing apparatus 10a First RF power supply 16 Shower head 61 Lifter pin 62 Lifting mechanism 100 Control unit

Claims (36)

A cleaning method in a plasma processing apparatus, comprising:
The plasma processing apparatus is
a processing vessel;
a substrate mounting table provided in the processing container;
a substrate lifting mechanism including lifter pins that support the substrate;
The cleaning method is
(a ) controlling the substrate lifting mechanism to raise the lifter pins to receive the dummy substrate loaded into the processing container;
( b ) controlling the substrate lifting mechanism to position the tips of the lifter pins above the substrate mounting table and lower than the position at which the dummy substrate is received ;
( c ) after the step ( b ) , using plasma to clean the inside of the processing container ;
(d) controlling the substrate elevating mechanism to raise the lifter pins to unload the dummy substrate out of the processing container;
A cleaning method. 2. The cleaning method according to claim 1, wherein the step (b) is performed after the step (a). 3. The cleaning method according to claim 1, wherein the step (d) is performed after the step (c). 4. The process according to any one of claims 1 to 3, wherein after the step (d), a step of cleaning the inside of the processing container using plasma is performed in a state in which the substrate and the dummy substrate are not accommodated in the processing container. cleaning method described in . (e) after ( a ), lowering the lifter pins to mount the dummy substrate on the substrate mounting table;
The step ( b ) according to any one of claims 1 to 4 , wherein after the step (e), the lifter pins are lifted to position the dummy substrate lower than the position where the dummy substrate was received. cleaning method. (f) after the step (e) and before the step ( b ), in a state in which the dummy substrate is mounted on the mounting surface of the substrate mounting table , plasma is applied to the inside of the processing container; 6. The cleaning method according to claim 5 , comprising the step of cleaning the . (g) after the step (c) and before the step (d), the step of lowering the lifter pins to mount the dummy substrate on the substrate mounting table; or one of the cleaning methods. (h) after the step (g) and before the step (d), in a state where the dummy substrate is mounted on the mounting surface of the substrate mounting table, plasma is used to move the inside of the processing container; 8. The cleaning method according to claim 7, comprising the step of cleaning. 9. The cleaning method according to any one of claims 1 to 8 , wherein in said step ( c ), a ring-shaped plasma is generated around the outer periphery of said substrate mounting table. 10. The separation distance between the mounting surface of the substrate mounting table and the surface of the dummy substrate facing the mounting surface is smaller than the thickness of the plasma sheath generated in the step ( c ). The cleaning method according to any one of. The cleaning according to any one of claims 1 to 10 , wherein a separation distance between the mounting surface of the substrate mounting table and the surface of the dummy substrate facing the mounting surface is 2.3 mm or more and 5 mm or less. Method. 12. The cleaning method according to claim 11 , wherein the separation distance between the mounting surface of said substrate mounting table and the surface of said dummy substrate facing said mounting surface is 2.3 mm or more and 3.5 mm or less. 12. The cleaning method according to claim 11 , wherein the separation distance between the mounting surface of said substrate mounting table and the surface of said dummy substrate facing said mounting surface is 2.3 mm or more and 3 mm or less. 14. The cleaning method according to any one of claims 1 to 13 , wherein the density of plasma generated in said step ( c ) is higher around the periphery of said dummy substrate than at the center of said dummy substrate. The plasma processing apparatus includes a ring member surrounding the outer circumference of the mounting surface of the substrate mounting table,
15. The cleaning method according to claim 14 , wherein the density of plasma generated in step ( c ) is higher at the inner peripheral portion of the ring member than at the outer peripheral portion of the ring member. 16. The cleaning method according to any one of claims 1 to 15 , wherein plasma of oxygen-containing gas is generated in said step ( c ). 17. The cleaning method according to any one of claims 1 to 16 , wherein in said step ( c ), high-frequency power for generating plasma is supplied to said substrate mounting table. 18. The cleaning method according to any one of claims 1 to 17 , wherein bias power is supplied to said substrate mounting table in said step ( c ). a processing vessel;
a substrate mounting table provided in the processing container;
a substrate lifting mechanism including lifter pins for supporting the substrate;
a control unit;
with
The control unit
(a ) a process of controlling the substrate elevating mechanism to raise the lifter pins to receive the dummy substrate loaded into the processing container;
( b ) a process of controlling the substrate lifting mechanism to position the tips of the lifter pins above the substrate mounting table and lower than the position at which the dummy substrate is received ;
( c ) after the treatment ( b ) , using plasma to clean the inside of the processing container ;
(d) a process of controlling the substrate lifting mechanism to lift the lifter pins and unloading the dummy substrate out of the processing container;
A plasma processing apparatus configured to perform The control unit
20. The plasma processing apparatus of claim 19 , configured to perform said process (b) after said process (a). The control unit
21. A plasma processing apparatus according to claim 19 or 20, configured to perform said process (d) after said process (c). The control unit
Claims 19 to 19, wherein after the process (d), a process of cleaning the inside of the processing container using plasma is performed in a state in which the substrate and the dummy substrate are not accommodated in the processing container. 22. The plasma processing apparatus according to any one of 21. The control unit
(e) a process of lowering the lifter pins to mount the dummy substrate on the substrate mounting table after the process ( a ), and performing the process after the process (e). 23. The plasma processing apparatus according to any one of claims 19 to 22, wherein in ( b ), the lifter pins are raised to position the dummy substrate lower than the position at which the dummy substrate was received . The control unit
(f) after the process (e) and before the process ( b ), in a state in which the dummy substrate is mounted on the mounting surface of the substrate mounting table , plasma is generated in the processing container; 24. The plasma processing apparatus of claim 23 , configured to perform a process of cleaning the . The control unit
(g) after the process (c) and before the process (d), the lifter pins are lowered to mount the dummy substrate on the substrate mounting table; Item 25. The plasma processing apparatus according to any one of items 19 to 24. The control unit
(h) after the process (g) and before the process (d), in a state where the dummy substrate is mounted on the mounting surface of the substrate mounting table, plasma is used to move the inside of the processing container; 26. The plasma processing apparatus of claim 25, configured to perform a process of cleaning. 27. The plasma processing apparatus according to any one of claims 19 to 26 , wherein in said processing ( c ), a ring-shaped plasma is generated around the outer periphery of said substrate mounting table. Claims 19 to 27, wherein the separation distance between the mounting surface of the substrate mounting table and the surface of the dummy substrate facing the mounting surface is smaller than the thickness of the plasma sheath generated in the process (c). The plasma processing apparatus according to any one of . The plasma according to any one of claims 19 to 28 , wherein a separation distance between the mounting surface of the substrate mounting table and the surface of the dummy substrate facing the mounting surface is 2.3 mm or more and 5 mm or less. processing equipment. 30. The plasma processing apparatus according to claim 29, wherein a separation distance between the mounting surface of said substrate mounting table and the surface of said dummy substrate facing said mounting surface is 2.3 mm or more and 3.5 mm or less. 30. The plasma processing apparatus according to claim 29, wherein a separation distance between the mounting surface of said substrate mounting table and the surface of said dummy substrate facing said mounting surface is 2.3 mm or more and 3 mm or less. 32. The plasma processing apparatus according to any one of claims 19 to 31 , wherein the density of plasma generated in said process ( c ) is higher around the periphery of said substrate than at the center of said dummy substrate. A ring member surrounding the outer periphery of the mounting surface of the substrate mounting table,
33. The plasma processing apparatus according to claim 32 , wherein the plasma generated in the process ( c ) has a higher density at the inner peripheral portion of the ring member than at the outer peripheral portion of the ring member. The control unit
34. A plasma processing apparatus according to any one of claims 19 to 33 , configured to generate a plasma of an oxygen-containing gas in said processing ( c ). 35. The plasma processing apparatus according to any one of claims 19 to 34, wherein in said processing (c), high-frequency power for generating plasma is supplied to said substrate mounting table. The control unit
36. The plasma processing apparatus according to any one of claims 19 to 35 , configured to supply bias power to said substrate mounting table in said processing ( c ).

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