JP4333866B2 - Substrate processing method and substrate processing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention dries various substrates typified by semiconductor wafers, glass substrates for liquid crystal display devices, glass substrates for plasma displays, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, photomask substrates and the like. The present invention relates to a substrate processing method and a substrate processing apparatus applied for the purpose.
[0002]
[Prior art]
For example, in a semiconductor device manufacturing process, a process of cleaning a semiconductor wafer (hereinafter simply referred to as “wafer”) is one of important processes.
An apparatus for performing a cleaning process includes a spin chuck that horizontally holds and rotates a wafer, and a blocking plate that is disposed opposite to the upper surface of the wafer held by the spin chuck. After cleaning the upper surface of the wafer with pure water, the shielding plate is brought close to the upper surface of the cleaned wafer, and nitrogen gas is supplied to the space between the wafer and the shielding plate to fill the nitrogen gas. In some cases, pure water adhering to the wafer is spun off and dried by rotating the wafer at high speed with a spin chuck (see, for example, Patent Document 1). Filling the space between the wafer and the shielding plate with nitrogen gas prevents the atmosphere containing pure water or oxygen from entering the space and prevents the generation of watermarks due to the reaction of pure water, oxygen, and silicon. It is for suppressing.
[0003]
However, the apparatus having such a configuration has a problem that a drop of pure water that has entered between the fine patterns formed on the wafer remains without being shaken, and a watermark is generated due to poor drying.
Therefore, it has been proposed to supply IPA (isopropyl alcohol) vapor in the space between the wafer and the shielding plate instead of nitrogen gas (see, for example, Patent Document 1). IPA vapor is supplied to the space between the wafer and the shielding plate, and the space between the wafer and the shielding plate is filled with the IPA vapor to prevent the atmosphere containing pure water or oxygen from entering the space. In addition, the pure water droplets remaining on the wafer upper surface without being shaken off can be removed by the volatility of the IPA vapor.
[0004]
In addition, pure water and IPA vapor are simultaneously supplied to the upper surface of the rotating wafer, and the supply position of the pure water and IPA vapor is gradually moved from the vicinity of the center of the wafer toward the peripheral edge, thereby providing an upper surface of the wafer. A method has also been proposed in which pure water used for the washing is quickly removed by the volatility of the IPA vapor while washing with pure water (see, for example, Patent Document 2).
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-41261
[Patent Document 2]
Japanese Patent Laid-Open No. 11-233481 (FIG. 1 on pages 6-7)
[0006]
[Problems to be solved by the invention]
However, in the method of supplying IPA vapor to the space between the wafer and the shielding plate, an atmosphere containing a cleaning solution or oxygen exists in the space between the wafer and the shielding plate before the supply of IPA vapor. Until this atmosphere is replaced with the IPA vapor atmosphere, a watermark due to the reaction of pure water, oxygen and silicon may occur on the upper surface of the wafer.
[0007]
On the other hand, in the method of supplying pure water and IPA vapor to the upper surface of the wafer at the same time, the supply position of pure water and IPA vapor must be moved, and a blocking plate cannot be used, so the pure water on the upper surface of the wafer is removed. There is a possibility that mist of pure water adheres to the part, and the wafer surface is recontaminated or a watermark is generated. In particular, when the spin chuck has a structure in which the wafer W can be rotated with a plurality of chuck pins, the pure water supplied to the peripheral edge of the wafer hits the chuck pins and rebounds, and the splash of pure water is splashed on the wafer. It will adhere to the dry part of the center.
[0008]
Accordingly, an object of the present invention is to provide a substrate processing method and a substrate processing apparatus that can dry the upper surface of a substrate satisfactorily without generating a watermark.
[0009]
[Means for Solving the Problems and Effects of the Invention]
  In order to achieve the above object, the present invention as claimed in claim 1 includes a substrate holding step for holding the substrate (W) substantially horizontally by the substrate holding means (1), and the substrate holding means after the substrate holding step. On top of the held substratePure waterSupplyWhile rotating the substrate at a rotation speed at which the rotation of the substrate is stopped or the liquid film formed on the upper surface of the substrate is not crushed,All over the top surface of the substratePure waterPour over to form a liquid film, thenPure waterA liquid film forming step of stopping the supply ofPrior to the liquid film forming step, a cleaning step of cleaning the upper surface of the substrate held by the substrate holding unit while supplying a cleaning solution, and the substrate holding unit held the cleaning step for a period of time. A substrate rotation process for rotating the substrate in a substantially horizontal plane;the aboveCleaning processAfterBefore the liquid film forming process startsAfter the covering step of bringing the substrate facing member (2) close to the upper surface of the substrate held by the substrate holding means and covering at least the central portion of the upper surface of the substrate with the substrate facing member, and after the liquid film forming step During the period in which the covering step is performed, the (first) drying gas is supplied toward the center of the upper surface of the substrate held by the substrate holding means.Then, the pure water forming the liquid film is driven toward the peripheral edge of the substrate.Dry gas supply processThe second dry gas is supplied to a region surrounding the supply position of the dry gas on the upper surface of the substrate during the period in which the liquid film forming step, the covering step, and the dry gas supply step are performed. Dry gas supply processIncludingThus, the drying gas is a gas containing drying acceleration steam that promotes drying of the substrate, and the second drying gas is an inert gas.This is a substrate processing method.
[0010]
The predetermined liquid may be pure water or functional water such as carbonated water, ionic water, reduced water (hydrogen water), or magnetic water.
In addition, the alphanumeric characters in parentheses represent corresponding components in the embodiments described later. The same applies hereinafter.
According to the above method, the dry gas is supplied toward the central portion of the upper surface of the substrate in a state where at least the central portion of the upper surface of the substrate on which the liquid film is formed is covered by the substrate facing member.
[0011]
When the drying gas is supplied to the upper surface of the substrate, the liquid forming the liquid film on the upper surface of the substrate is sequentially driven away from the central portion of the substrate to the peripheral portion of the substrate by the drying gas. Eliminated from the flow. Thereby, the upper surface of the substrate is dried from the central portion (dry gas supply position) toward the periphery. In other words, a substantially annular boundary line (hereinafter referred to as a drying boundary) between a portion where the liquid is excluded (center portion of the substrate) and a portion where the liquid is not excluded (substrate peripheral portion) is referred to as a drying boundary. It moves so that it may spread in order from the center part of a board | substrate to the peripheral part of a board | substrate.
[0012]
In this process, since the dry gas is supplied to the portion from which the liquid film has been removed, there is no risk of contact with an atmosphere containing oxygen or the like that causes the generation of the watermark. On the other hand, the portion where the liquid film has not been removed is also protected by the liquid film, so that there is no risk of contact with an atmosphere containing oxygen or the like. In addition, since the central portion of the upper surface of the substrate is covered with the substrate facing member, splashes of liquid flowing down from the peripheral edge of the substrate may adhere to the portion of the upper surface of the substrate where the liquid film is excluded. Absent. Therefore, the upper surface of the substrate can be satisfactorily dried without generating a watermark.
[0014]
  AlsoSince the drying of the substrate is promoted with respect to the liquid film on the upper surface of the substrate, the liquid forming the liquid film can be quickly evaporated. Thereby, it is possible to prevent the occurrence of watermarks due to poor drying.
  In addition, when the drying promotion vapor | steam of the said dry gas is a volatile substance which is hydrophilic and can be melt | dissolved in the said predetermined liquid (soluble), the volatilization rate of the liquid will melt | dissolve in the liquid. And poor drying of the substrate can be prevented. On the other hand, when the drying accelerating vapor of the drying gas is lipophilic (hydrophobic) and insoluble in the predetermined liquid, the predetermined liquid can be easily pushed out of the substrate. It is possible to prevent poor drying of the substrate. Therefore, even if the drying accelerating vapor is either soluble or insoluble in the liquid, the substrate can be dried more rapidly while maintaining the above-mentioned drying boundary well.
In addition, since the liquid flows from the central part to the peripheral part of the substrate due to the centrifugal force accompanying the rotation of the substrate, the liquid film can be uniformly spread in the liquid film forming step, and in the dry gas supplying step Can quickly widen the drying boundary, and can dry the upper surface of the substrate more quickly.
Furthermore, during the period in which the liquid film forming step, the covering step, and the dry gas supply step are performed, a second dry gas stream is formed around the dry gas, so that the liquid film on the substrate is eliminated. It is possible to more reliably prevent the portion from being exposed to an atmosphere containing oxygen or the like that causes the generation of a watermark.
In addition, in the space between the substrate and the substrate-facing member, an air flow of drying accelerating steam and an inert gas surrounding it is formed. Accordingly, it is possible to perform good drying with the drying accelerating steam while preventing the atmosphere containing the oxygen outside from being satisfactorily blocked by the air flow of the inert gas, and it is possible to prevent the generation of the watermark.
[0015]
  Claims2As described, the dry gas supply step preferably includes a step of gradually increasing the supply flow rate of the dry gas.
  In this case, in the initial stage of the dry gas supply process, the area of the portion where the liquid film at the center of the substrate is removed is small, so that the dry gas supply flow rate is preferably relatively small. This is because if too much drying gas is supplied, the liquid film on the upper surface of the substrate is divided, and the above-mentioned drying boundary is disturbed, resulting in poor drying. On the other hand, as the dry gas supply process proceeds, the area of the portion where the liquid film at the center of the substrate is removed gradually increases (the peripheral length of the drying boundary increases). It is preferable to gradually increase the supply flow rate of the drying gas in order to spread it well without disturbing. Thereby, the above-mentioned drying boundary can be expanded well, and generation of a watermark due to poor drying can be more reliably prevented. And this claim2In the case where the drying gas contains drying accelerating steam, the effect can be further improved. In addition, the supply flow rate of the dry gas may be gradually increased gradually or may be gradually increased stepwise.
[0017]
  Claim3The described invention is characterized in that the substrate rotation step includes a step of gradually increasing the rotation speed of the substrate during the period in which the dry gas supply step is performed.1 or 2It is a substrate processing method of description.
  In this case, since the area of the portion where the liquid film at the center of the substrate is removed is small at the initial stage of the substrate rotation process, it is preferable that the rotation speed of the substrate is relatively low. This is because if the rotational speed of the substrate is increased too quickly from the beginning, the liquid film on the upper surface of the substrate is divided and the above-mentioned drying boundary is disturbed, resulting in poor drying. Furthermore, if the rotation speed of the substrate is increased too much from the beginning, the drying speed is slower in the center of the substrate due to the centrifugal force acting on the liquid film on the substrate, and droplets are generated in the center of the substrate. It may remain. On the other hand, if the substrate rotation process proceeds and the portion of the substrate where the liquid is excluded sufficiently spreads, the above-mentioned problems of the drying boundary disturbance and droplet remaining will be solved. Accordingly, it is preferable to gradually increase the rotation speed of the substrate in order to speed up the drying process. Thereby, the above-mentioned drying boundary can be expanded well, and generation of a watermark due to poor drying can be more reliably prevented. This claim3In the case where the drying gas contains drying accelerating steam, the effect can be further improved. Note that the rotation speed of the substrate may be gradually increased gradually or may be gradually increased step by step.
[0020]
  Claim4The described invention holds the substrate (W) almost horizontally.Then rotateOn the upper surface of the substrate held by the substrate holding means (1)Pure waterTo the entire upper surface of the substrate.Pure waterThe liquid film forming means (4, 41, 252, 252a) for forming a liquid film by piling up the liquid and the substrate are disposed opposite to each other at a position close to the upper surface of the substrate held by the substrate holding means. A substrate facing member (2) for covering at least the central part of the upper surface of the substrate;Elevating drive means (23) for elevating the substrate facing member relative to the substrate held by the substrate holding means;A dry gas supply means (3, 31, 32, 251, 251a) for supplying a dry gas toward the center of the upper surface of the substrate held by the substrate holding means;Second dry gas supply means (5, 26, 26a, 51) for supplying a second dry gas to an area surrounding the supply position of the dry gas on the upper surface of the substrate, the substrate holding means,The liquid film forming meansThe elevating drive means, the dry gas supply means and the second dry gas supply meansControlPure water is supplied to the upper surface of the substrate held by the substrate holding means, and the rotation of the substrate is stopped or the substrate is rotated at a rotation speed at which the liquid film formed on the upper surface of the substrate is not crushed. A liquid film forming step of forming pure liquid over the entire upper surface to form a liquid film, and then stopping the supply of pure water; and before the liquid film forming step, the substrate held by the substrate holding means A cleaning process for cleaning the upper surface while supplying a cleaning liquid, a substrate rotating process for rotating the substrate held by the substrate holding means in a substantially horizontal plane during the cleaning process, and the cleaning process. A covering step of bringing the substrate facing member close to the upper surface of the substrate held by the substrate holding means and covering at least the central portion of the upper surface of the substrate with the substrate facing member after the liquid film forming step is started after And after the liquid film forming step During the period in which the coating process is performed, the drying gas is supplied toward the center of the upper surface of the substrate held by the substrate holding means, and the pure water forming the liquid film is supplied to the peripheral portion of the substrate. A region surrounding the dry gas supply position on the upper surface of the substrate during a period in which the dry gas supply step, the liquid film forming step, the coating step, and the dry gas supply step are performed; A second drying gas supply step for supplying a drying gas;Including control means (6)Thus, the drying gas is a gas containing drying acceleration steam that promotes drying of the substrate, and the second drying gas is an inert gas.This is a substrate processing apparatus.
[0021]
According to this configuration, an effect similar to the effect described in relation to claim 1 can be achieved.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a diagram schematically showing the configuration of a substrate processing apparatus according to an embodiment of the present invention. This substrate processing apparatus is an apparatus that performs processing of cleaning wafers W as an example of a substrate one by one and drying the cleaned wafers W. The spin chuck 1 that rotates while holding the wafers W almost horizontally. And a disc-shaped blocking plate 2 provided substantially horizontally above the spin chuck 1.
[0023]
The spin chuck 1 includes, for example, a spin shaft 11 extending in a substantially vertical direction, a spin base 12 attached to an upper end of the spin shaft 11, and a plurality of chuck pins disposed on a peripheral portion of the spin base 12. 13, and the wafer W is held in a horizontal state by sandwiching the end face of the wafer W in cooperation with a plurality of chuck pins 13. Further, the spin shaft 11 is coupled with a rotation drive mechanism 14 including a drive source such as a motor, and the rotational force from the rotation drive mechanism 14 to the spin shaft 11 while the wafer W is held horizontally by the chuck pins 13. Is input, the wafer W can be rotated in a substantially horizontal plane.
[0024]
The blocking plate 2 is formed to have a diameter that is substantially the same as or slightly larger than that of the wafer W, and is a cylindrical support that is disposed on an axis common to the spin axis 11 (rotation axis of the wafer W). It is connected to the lower end of the shaft 21. An arm 22 is provided above the blocking plate 2, and the support shaft 21 is supported in a state where it is suspended from the tip of the arm 22. The arm 22 is coupled to a lift drive mechanism 23, and the arm 22 is lifted and lowered by the lift drive mechanism 23, so that the blocking plate 2 is brought into contact with the upper surface of the wafer W held by the spin chuck 1. It can be separated.
[0025]
An opening 24 is formed at the center of the blocking plate 2, and the hollow portion of the support shaft 21 communicates with the opening 24. A pipe member 25 having a first dry gas flow passage 251 and a liquid flow passage 252 is inserted into the hollow portion of the support shaft 21 in a non-contact state with the support shaft 21. The distal end (lower end) of the pipe member 25 reaches the opening 24, and the distal ends of the first dry gas flow passage 251 and the liquid flow passage 252 open at the distal end surface of the pipe member 25, respectively. A supply port 251a and a liquid supply port 252a are formed.
[0026]
The first dry gas supply pipe 3 is connected to the first dry gas flow passage 251. The first dry gas supply pipe 3 is connected to a nitrogen gas (N₂) Or nitrogen gas containing IPA vapor (IPA + N₂) Is selectively supplied as the first drying gas. The nitrogen gas supplied to the first dry gas supply pipe 3 or the nitrogen gas containing IPA vapor passes through the first dry gas flow passage 251 and passes through the first dry gas flow passage 251 at the first dry gas supply port 251a. Are discharged toward the center of the upper surface of the wafer W held by the spin chuck 1.
[0027]
A liquid supply pipe 4 is connected to the liquid flow passage 252, and either cleaning liquid or pure water (DIW) is selectively supplied to the liquid supply pipe 4 via valves 41 and 42. It has come to be. The cleaning liquid or pure water supplied to the liquid supply pipe 4 passes through the liquid flow path 252, and from the liquid supply port 252 a at the tip of the liquid flow path 252, the center portion of the upper surface of the wafer W held by the spin chuck 1. It is discharged toward. Although not shown, a liquid supply port that discharges cleaning liquid and pure water toward the center of the “lower surface” of the wafer W, a liquid flow passage, a liquid supply pipe, a valve, and the like associated therewith are provided on the wafer. It is provided in the same manner as the above configuration on the W upper surface side.
[0028]
Further, a space 26 having a ring-shaped cross section is formed between the inner peripheral surface of the support shaft 21 and the pipe member 25, and the second dry gas is supplied from the second dry gas supply pipe 5 to the space 26. Nitrogen gas (N₂) Is supplied. The nitrogen gas supplied to the space 26 is discharged toward the upper surface of the wafer W held by the spin chuck 1 from the second dry gas supply port 26a having a ring-shaped cross section between the peripheral edge of the opening 24 and the tube member 25. Is done. That is, the space 26 between the inner peripheral surface of the support shaft 21 and the pipe member 25 is a second dry gas flow passage through which nitrogen gas as the second dry gas flows, and this second dry gas flow passage. The nitrogen gas flowing through the nozzle 26 is discharged from the second drying gas supply port 26a and supplied to a ring-shaped region surrounding the first drying gas supply position and the liquid supply position on the upper surface of the wafer W. A valve 51 for controlling the supply of nitrogen gas to the second dry gas flow passage 26 is interposed in the middle of the second dry gas supply pipe 5.
[0029]
FIG. 2 is a block diagram showing an electrical configuration of the substrate processing apparatus. The substrate processing apparatus further includes a control device 6 including a microcomputer, for example. The control device 6 controls the operations of the rotary drive mechanism 14 and the lift drive mechanism 23 according to a predetermined program for processing the wafer W, and opens and closes the valves 31, 32, 41, 42, 51. Control.
FIG. 3 is a view for explaining the processing of the wafer W in this substrate processing apparatus. When the wafer W to be processed is delivered to the spin chuck 1, first, a process for cleaning the wafer W is performed. In this cleaning step, for example, the rotation drive mechanism 14 is controlled to open the valve 42 while the wafer W is rotated at a predetermined rotation speed, and the cleaning liquid is supplied to the upper surface of the rotating wafer W. The cleaning liquid supplied to the upper surface of the wafer W receives centrifugal force due to the rotation of the wafer W and flows from the supply position toward the periphery of the wafer W. As a result, the cleaning liquid spreads over the entire upper surface of the wafer W, and the upper surface of the wafer W is cleaned by the cleaning liquid.
[0030]
Examples of cleaning liquids include chemical liquids such as hydrofluoric acid, hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, acetic acid, ammonia and aqueous hydrogen peroxide solutions thereof, pure water, carbonated water, ionic water, reduced water (hydrogen water), or magnetic Functional water such as water can be exemplified.
The cleaning liquid is supplied to the upper surface of the wafer W from the liquid supply port 252 a of the liquid flow path 252. After the cleaning with the cleaning liquid, pure water is supplied to the upper surface of the wafer W, and a rinsing process is performed to wash away the cleaning liquid adhering to the surface of the wafer W after the chemical liquid cleaning. The pure water for the rinsing process is supplied to the upper surface of the wafer W from the liquid supply port 252a.
[0031]
In addition, when pure water is used as the cleaning liquid, it is not necessary to provide the valve 42 and the cleaning liquid supply source connected to the valve 42 in FIG. 1, and the valve 41 and the pure water supply source connected thereto may be used. Good.
When the cleaning process is completed, the rotation driving mechanism 14 is controlled to stop the rotation of the wafer W. Further, the lifting drive mechanism 23 is controlled so that the blocking plate 2 is disposed at a position close to the upper surface of the wafer W held by the spin chuck 1. Then, the valve 41 is controlled (opened), and pure water is supplied to the upper surface of the wafer W from the liquid supply port 252a. The pure water supplied to the upper surface of the wafer W spreads on the upper surface of the wafer W and is stored as a liquid film on the wafer W by its surface tension (liquid accumulation).
[0032]
Further, while the pure water is being deposited, the valves 31 and 51 are controlled so that the first drying gas supply port 251a and the second drying gas supply port 26a are respectively supplied to the upper surface of the wafer W from the first drying. Nitrogen gas as the gas and nitrogen gas as the second drying gas are supplied. The supply flow rate of nitrogen gas is set to such a flow rate that the liquid film of pure water formed on the wafer W is not crushed. For example, 5 liters of nitrogen gas per minute is supplied from the first dry gas supply port 251a. Then, 50 liters of nitrogen gas is supplied from the second dry gas supply port 26a. Thus, the atmosphere in the space between the pure water liquid film on the wafer W and the blocking plate 2 can be replaced with nitrogen gas, and the entry of the atmosphere containing oxygen from the outside into the space is prevented. Can do.
[0033]
As shown in FIG. 4, the supply flow rate of nitrogen gas from the second dry gas supply port 26a is set larger than the supply flow rate of nitrogen gas from the first dry gas supply port 251a. This is because the opening area of the second dry gas supply port 26a is larger than that of the first dry gas supply port 251a, and the flow rate of nitrogen gas supplied from the second dry gas supply port 26a is supplied from the first dry gas supply port 251a. Is approximately equal to the flow rate of nitrogen gas.
[0034]
When a sufficient amount of pure water is supplied to the upper surface of the wafer W to form a liquid film of pure water over the entire upper surface of the wafer W, the valve 41 is closed and the wafer W is placed on the wafer W. The liquid filling process for forming the pure water liquid film is completed, and then the IPA vapor supply process is performed. In the IPA vapor supply step, after the valve 31 is closed, the valve 32 is controlled (opened), and nitrogen gas containing IPA vapor is supplied from the first dry gas supply port 251a to the center of the upper surface of the wafer W. . Further, the valve 51 is opened continuously from the liquid filling step, and for example, 50 liters of nitrogen gas is continuously supplied from the second dry gas supply port 26a. Even in the IPA vapor supply process, the rotation of the wafer W is stopped while continuing from the previous liquid filling process.
[0035]
The supply flow rate of nitrogen gas containing IPA vapor is gradually increased to, for example, 50 liters per minute by controlling the opening degree of a flow rate adjustment valve (not shown) inserted in the first dry gas supply pipe 3. (Or step by step). That is, at the initial stage of supplying nitrogen gas containing IPA vapor, the area of the portion where the liquid film at the center of the wafer W is removed is small, so the supply flow rate of nitrogen gas containing IPA vapor is kept relatively small. On the other hand, since the area of the portion where the liquid film is removed increases as the drying of the wafer W progresses, the gas supply flow rate is gradually increased. As a result, the upper surface of the wafer W is directed from the center to the periphery without disturbing the drying boundary (the substantially annular boundary between the portion where the liquid film is excluded and the portion where the liquid film is not excluded). Dry in order. As a result, it is possible to prevent drying failure on the upper surface of the wafer W and to prevent generation of a watermark.
[0036]
In particular, the IPA aqueous solution that flows from the center to the periphery of the wafer W is also mixed with pure water that has entered between fine patterns formed on the upper surface of the wafer W, and the pure water is quickly evaporated from the upper surface of the wafer W. Let Further, since the supply flow rate of the nitrogen gas containing IPA vapor is finally raised to 50 liters per minute, the nitrogen gas containing IPA vapor reaches the peripheral edge of the wafer W. Or even if the droplet of the diluted IPA aqueous solution remains, the droplet evaporates as the IPA vapor further dissolves. Therefore, the entire upper surface of the wafer W can be satisfactorily dried without generating a watermark due to poor drying.
[0037]
In addition, supply of nitrogen gas containing IPA vapor is started in a state where the space between the liquid film on the wafer W and the blocking plate 2 is filled with nitrogen gas in advance, and then the liquid film on the upper surface of the wafer W Nitrogen gas containing IPA vapor is continuously supplied to the removed portion. In addition, since nitrogen gas is continuously supplied from the second dry gas supply port 26a between the wafer W and the shielding plate 2, there is no possibility that an atmosphere containing oxygen or the like enters from the outside. Therefore, an atmosphere containing oxygen or the like does not touch the portion of the wafer W from which the liquid film has been removed, and there is no possibility of generating a watermark due to the reaction of oxygen, pure water, and silicon.
[0038]
Note that only before the start of supply of nitrogen gas containing IPA vapor, the space between the liquid film on the wafer W and the shielding plate 2 is filled with nitrogen gas in advance, and after the start of supply of nitrogen gas containing IPA vapor, The nitrogen gas may not be supplied from the second dry gas supply port 26a. Or conversely, before the supply of nitrogen gas containing IPA vapor is started, the space between the liquid film on the wafer W and the blocking plate 2 is not filled with nitrogen gas in advance, and supply of nitrogen gas containing IPA vapor is performed. The nitrogen gas may be supplied from the second dry gas supply port 26a only after the start.
[0039]
When a predetermined time elapses after the supply flow rate of nitrogen gas containing IPA vapor reaches 50 liters per minute, the IPA vapor supply process ends, and thereafter, the rotational drive mechanism 14 is controlled to set the wafer W in a predetermined height. A spin dry process is performed in which the liquid is rotated at a rotational speed (for example, 3000 rpm), and droplets of pure water mainly adhering to the lower surface of the wafer W are shaken off by a centrifugal force and dried. During this spin drying process, supply of nitrogen gas including IPA vapor from the first dry gas supply port 251a and supply of nitrogen gas from the second dry gas supply port 26a are continued. Thereby, it is possible to prevent an atmosphere containing pure water or oxygen swung from the lower surface of the wafer W from entering between the wafer W and the blocking plate 2, and to prevent contamination of the upper surface of the wafer W by such an atmosphere. can do.
[0040]
As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form. For example, in the liquid filling process, the wafer W may be rotated at a rotational speed (for example, 50 rpm or less) such that the liquid film of pure water is not crushed.
Further, the wafer W may be rotated in the IPA vapor supply process, and by rotating the wafer W, it is possible to promote the flow of pure water and the IPA aqueous solution from the upper surface of the wafer W. The rotational speed of the wafer W in the IPA vapor supply process may be a constant low rotational speed (for example, 50 rpm). For example, the rotational speed of the wafer W during the spin dry process (for example, from the state where the rotation is stopped) You may make it raise to 3000 rpm gradually. In this way, the wafer W can be quickly dried without causing the disturbance of the drying boundary on the upper surface of the wafer W and the remaining of the droplets.
[0041]
Further, during rotation of the wafer W, it is preferable to rotate the blocking plate 2 in the same direction as the wafer W at substantially the same rotational speed. By doing so, it is possible to prevent the turbulence of the airflow particularly in the vicinity of the peripheral edge of the upper surface of the wafer W, and to satisfactorily prevent the atmosphere containing oxygen or the like from entering between the wafer W and the shielding plate 2 from the outside. . In order to rotate the blocking plate 2, a support shaft 21 is rotatably provided at the tip of the arm 22, and a rotational force from a rotational drive mechanism including a motor is input to the support shaft 21. That's fine.
[0042]
Furthermore, in the spin dry process, nitrogen gas containing IPA vapor is discharged from the first dry gas supply port 251a. 3 may be discharged toward the upper surface of the wafer W from the first dry gas supply port 251a.
In the above embodiment, the spin chuck 1 has a configuration in which the end surface of the wafer W is sandwiched by a plurality of chuck pins 13. For example, in a state where the device formation surface of the wafer W faces upward. A structure (vacuum chuck) that can hold the wafer W substantially horizontally by vacuum-sucking the non-device forming surface (lower surface) of the wafer W may be employed.
[0043]
Furthermore, in the above embodiment, IPA vapor is exemplified as the drying accelerating steam. However, nitrogen gas containing steam (vapor) of a highly volatile solvent having excellent hydrophilicity, such as alcohols typified by methanol or acetone. By supplying to the surface of the wafer W, the same effect as when nitrogen gas containing IPA vapor is supplied can be achieved. Alternatively, a highly lipophilic (non-soluble) liquid vapor represented by HFE (hydrofluoroether) may be supplied to the surface of the wafer W as the drying accelerating vapor, and the same effect can be achieved by this. .
[0044]
Furthermore, in the above embodiment, a liquid film of pure water is formed on the upper surface of the wafer W after the cleaning process. However, functional water is supplied from the liquid supply port 252a to the upper surface of the wafer W, and this function is performed. A liquid film of water may be formed on the upper surface of the wafer W. In this case, when functional water is used as the cleaning liquid in the cleaning process, the functional water may be supplied to the upper surface of the wafer W from the liquid supply port 252a.
In addition, various design changes can be made within the scope of the matters described in the claims.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing a configuration of a substrate processing apparatus according to an embodiment of the present invention.
FIG. 2 is a block diagram showing an electrical configuration of the substrate processing apparatus.
FIG. 3 is a diagram for explaining processing in the substrate processing apparatus.
FIG. 4 is a diagram illustrating a configuration of a lower surface of a blocking plate.
[Explanation of symbols]
1 Spin chuck
2 Barrier plate
3 First dry gas supply pipe
4 Liquid supply pipe
5 Second dry gas supply pipe
6 Control device
24 opening
25 Pipe members
251 First dry gas flow passage
251a First dry gas supply port
252 Liquid flow path
252a Liquid supply port
26 Second drying gas flow passage
26a Second dry gas supply port
31 Valve
32 valves
41 Valve
42 Valve
51 valve
W wafer

Claims (4)

A substrate holding step of holding the substrate substantially horizontally by the substrate holding means;
After this substrate holding step, pure water is supplied to the upper surface of the substrate held by the substrate holding means, and the substrate is rotated at such a rotational speed that the rotation of the substrate is stopped or the liquid film formed on the upper surface of the substrate is not crushed. while rotating, the liquid film forming step of the liquid film is formed by a puddle of pure water on the entire upper surface of the substrate, and then stops the supply of pure water,
Before the liquid film forming step, a cleaning step of cleaning the upper surface of the substrate held by the substrate holding means while supplying a cleaning liquid;
A substrate rotating step of rotating the substrate held by the substrate holding means in a substantially horizontal plane during the period in which the cleaning step is performed;
After the cleaning step and before the start of the liquid film forming step , the substrate facing member is brought close to the upper surface of the substrate held by the substrate holding means, and at least the central portion of the upper surface of the substrate by the substrate facing member Covering process for covering,
During the period in which the coating step is performed after the liquid film forming step, a dry gas is supplied toward the center of the upper surface of the substrate held by the substrate holding means to form a liquid film. A dry gas supply process that drives pure water toward the peripheral edge of the substrate ;
Second drying for supplying a second drying gas to a region surrounding the supply position of the drying gas on the upper surface of the substrate during the period in which the liquid film formation step, the coating step, and the drying gas supply step are performed. look including the <br/> gas supply step,
The substrate processing method, wherein the drying gas is a gas containing drying acceleration steam for promoting the drying of the substrate, and the second drying gas is an inert gas . The drying gas supply step, the substrate processing method according to claim 1, characterized in that it comprises a step of gradually increasing the supply flow rate of the drying gas. The substrate rotating step, during which the drying gas supply step is performed, the substrate processing method according to claim 1 or 2, characterized in that it comprises a step of gradually increasing the rotational speed of the substrate. A substrate holding device you want to rotate. Substantially horizontally holding the substrate,
A liquid film forming means for supplying pure water to the upper surface of the substrate held by the substrate holding means and forming a liquid film by depositing pure water over the entire upper surface of the substrate;
A substrate-opposing member disposed opposite to the upper surface of the substrate held by the substrate holding means and covering at least the center of the upper surface of the substrate;
Elevating drive means for elevating the substrate facing member relative to the substrate held by the substrate holding means;
A drying gas supply means for supplying a drying gas toward the central portion of the upper surface of the substrate held by the substrate holding means;
Second dry gas supply means for supplying a second dry gas to a region surrounding the dry gas supply position on the upper surface of the substrate;
The substrate holding means, the liquid film forming means , the elevating drive means, the dry gas supply means, and the second dry gas supply means are controlled to supply pure water to the upper surface of the substrate held by the substrate holding means. Supply and stop the rotation of the substrate or rotate the substrate at a rotation speed that does not crush the liquid film formed on the upper surface of the substrate, and form a liquid film by pouring pure water over the entire upper surface of the substrate Then, a liquid film forming step of stopping the supply of pure water, a cleaning step of cleaning the upper surface of the substrate held by the substrate holding means while supplying a cleaning liquid before the liquid film forming step, and the cleaning While the process is being performed, the substrate rotation process for rotating the substrate held by the substrate holding means in a substantially horizontal plane, and after the cleaning process and before the start of the liquid film forming process, On the upper surface of the substrate held by the substrate holding means The substrate facing member, and the substrate facing member covering at least the center of the upper surface of the substrate with the substrate facing member; and during the period in which the coating step is performed after the liquid film forming step. A dry gas supply step of supplying a dry gas toward the central portion of the upper surface of the substrate held by the holding means and driving pure water forming the liquid film toward the peripheral portion of the substrate; and the liquid film forming step A second dry gas supply step for supplying a second dry gas to a region surrounding the dry gas supply position on the upper surface of the substrate during the period in which the coating step and the dry gas supply step are performed. and a control means for performing only contains,
The substrate processing apparatus, wherein the drying gas is a gas containing drying acceleration steam for promoting drying of the substrate, and the second drying gas is an inert gas .

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