JP6585242B2 - Substrate cleaning apparatus, substrate cleaning method, and storage medium - Google Patents

Description

Embodiments disclosed herein relate to a substrate cleaning apparatus , a substrate cleaning method, and a storage medium .

  Conventionally, there has been known a substrate cleaning apparatus that removes particles adhering to a substrate such as a silicon wafer or a compound semiconductor wafer.

  As this type of substrate cleaning apparatus, there is an apparatus that removes particles by using a physical force generated by supplying a fluid such as liquid or gas to the surface of the substrate (see Patent Document 1). There is also known a substrate cleaning apparatus that supplies a chemical solution such as SC1 to the surface of a substrate and removes particles using a chemical action (for example, etching action) of the supplied chemical liquid (see Patent Document 2). .

JP-A-8-318181 JP 2007-258462 A

  However, in the technique of removing particles using physical force as in the technique described in Patent Document 1, there is a possibility that the pattern formed on the surface of the substrate collapses due to physical force.

  Further, in the technique of removing particles using the chemical action of a chemical solution as in the technique described in Patent Document 2, there is a possibility that the base film of the substrate may be eroded by an etching action or the like.

An object of one embodiment is to provide a substrate cleaning apparatus , a substrate cleaning method, and a storage medium that can remove particles attached to a substrate while suppressing pattern collapse and erosion of a base film.

Substrate cleaning apparatus according to one aspect of the embodiment includes a first liquid supply portion, and a second liquid supply portion. The first liquid supply unit supplies a processing liquid for forming a film on the substrate, including a volatile component and a synthetic resin having a property of shrinking in volume when solidified or cured . The second liquid supply unit is supplied to the substrate by the first liquid supply unit, a remover to remove all of the processing liquid to solid on or hardened treatment liquid on the substrate by the volatile components is evaporated provided that a teapot. Further, the substrate cleaning apparatus according to one aspect of the embodiment is caused by distortion caused by volume shrinkage of the synthetic resin when the processing liquid supplied from the first liquid supply unit and covering the pattern on the substrate is solidified or cured. The particles attached to the pattern are separated from the pattern.

  According to one aspect of the embodiment, particles attached to the substrate can be removed while suppressing pattern collapse and erosion of the base film.

FIG. 1 is a schematic diagram illustrating a schematic configuration of the substrate cleaning system according to the first embodiment. FIG. 2A is an explanatory diagram of a substrate cleaning method. FIG. 2B is an explanatory diagram of the substrate cleaning method. FIG. 2C is an explanatory diagram of the substrate cleaning method. FIG. 3 is a schematic diagram showing the configuration of the substrate cleaning apparatus according to the first embodiment. FIG. 4 is a flowchart showing a processing procedure of the substrate cleaning process executed by the substrate cleaning apparatus. FIG. 5A is an operation explanatory diagram of the substrate cleaning apparatus. FIG. 5B is an operation explanatory diagram of the substrate cleaning apparatus. FIG. 5C is an operation explanatory diagram of the substrate cleaning apparatus. FIG. 5D is an operation explanatory diagram of the substrate cleaning apparatus. FIG. 5E is an operation explanatory diagram of the substrate cleaning apparatus. FIG. 5F is an operation explanatory diagram of the substrate cleaning apparatus. FIG. 6 is a schematic diagram illustrating a configuration of the substrate cleaning apparatus according to the second embodiment. FIG. 7 is a schematic diagram illustrating a configuration of a substrate cleaning apparatus according to the third embodiment. FIG. 8 is an explanatory view of the operation of the substrate cleaning apparatus according to the third embodiment. FIG. 9 is a schematic diagram illustrating a configuration of a substrate cleaning apparatus according to the fourth embodiment. FIG. 10A is a schematic diagram illustrating a configuration of a rotation holding mechanism according to a fifth embodiment. FIG. 10B is a schematic diagram illustrating a configuration of a rotation holding mechanism according to the fifth embodiment. FIG. 11A is a diagram illustrating the wafer transfer timing. FIG. 11B is a diagram illustrating another example of the wafer transfer timing. FIG. 12A is an explanatory diagram of a comparison condition between this cleaning method and two-fluid cleaning. FIG. 12B is an explanatory diagram of comparison conditions between this cleaning method and two-fluid cleaning. FIG. 13 is a diagram showing a comparison result between this cleaning method and two-fluid cleaning. FIG. 14 is a diagram showing a comparison result between this cleaning method and chemical cleaning. FIG. 15 is a diagram showing a comparison result between this cleaning method and chemical cleaning.

Hereinafter, embodiments of a substrate cleaning apparatus , a substrate cleaning method, and a storage medium disclosed in the present application will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by embodiment shown below.

(First embodiment)
<Schematic configuration of substrate cleaning system>
First, a schematic configuration of the substrate cleaning system according to the first embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating a schematic configuration of a substrate cleaning system according to the first embodiment.

  In the following, in order to clarify the positional relationship, the X axis, the Y axis, and the Z axis that are orthogonal to each other are defined, and the positive direction of the Z axis is the vertically upward direction. In the following, the X-axis negative direction side is defined as the front side of the substrate cleaning system, and the X-axis positive direction side is defined as the rear side of the substrate cleaning system.

  As shown in FIG. 1, the substrate cleaning system 100 includes a carry-in / out station 1, a transfer station 2, and a processing station 3. The carry-in / out station 1, the transfer station 2, and the processing station 3 are arranged from the front to the rear of the substrate cleaning system 100 in the order of the carry-in / out station 1, the transfer station 2, and the processing station 3.

  The carry-in / out station 1 is a place where a carrier C that accommodates a plurality of (for example, 25) wafers W in a horizontal state is placed. For example, four carriers C are brought into close contact with the front wall of the transfer station 2. Placed side by side in the state of being.

  The transfer station 2 is disposed behind the carry-in / out station 1 and includes a substrate transfer device 2a and a substrate delivery table 2b. In the transfer station 2, the substrate transfer device 2 a transfers the wafer W between the carrier C placed on the transfer-in / out station 1 and the substrate transfer table 2 b.

  The processing station 3 is disposed behind the transfer station 2. In the processing station 3, a substrate transfer device 3a is arranged at the center, and a plurality (here, six) of substrate cleaning devices 5 are arranged in the front-rear direction on the left and right sides of the substrate transfer device 3a. . In the processing station 3, the substrate transfer device 3 a transfers the wafers W one by one between the substrate delivery table 2 b of the transfer station 2 and each substrate cleaning device 5. Substrate cleaning process one by one.

  Further, the substrate cleaning system 100 includes a control device 6. The control device 6 is a device that controls the operation of the substrate cleaning system 100. The control device 6 is a computer, for example, and includes a control unit and a storage unit (not shown). The storage unit stores a program for controlling various processes such as a substrate cleaning process. The control unit controls the operation of the substrate cleaning system 100 by reading and executing the program stored in the storage unit.

  Such a program may be recorded on a computer-readable storage medium and installed in the storage unit of the control device 6 from the storage medium. Examples of the computer-readable storage medium include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnetic optical disk (MO), and a memory card.

  1 shows a case where the control device 6 is provided outside the substrate cleaning system 100 for convenience, but the control device 6 may be provided inside the substrate cleaning system 100. For example, the control device 6 can be accommodated in the upper space of the substrate cleaning device 5.

  In the substrate cleaning system 100 configured as described above, first, the substrate transfer device 2a of the transfer station 2 takes out one wafer W from the carrier C placed on the carry-in / out station 1, and the taken wafer W is transferred to the substrate. Place on the delivery table 2b. The wafer W placed on the substrate delivery table 2b is transferred by the substrate transfer device 3a of the processing station 3 and is transferred into one of the substrate cleaning devices 5.

  The wafer W carried into the substrate cleaning device 5 is subjected to a substrate cleaning process by the substrate cleaning device 5, and then is carried out of the substrate cleaning device 5 by the substrate transfer device 3a and placed again on the substrate delivery table 2b. . Then, the processed wafer W placed on the substrate delivery table 2b is returned to the carrier C by the substrate transfer device 2a.

  Here, in the conventional substrate cleaning apparatus, particle removal using physical force and particle removal using chemical action of chemicals are performed. However, with these methods, there is a possibility that the pattern formed on the surface of the wafer collapses due to physical force, or the underlying film of the wafer is eroded by an etching action or the like.

  Therefore, in the substrate cleaning apparatus 5 according to the first embodiment, instead of these methods, by removing particles using the volume change of the processing liquid, the wafer W is suppressed while suppressing pattern collapse and erosion of the base film. It was decided to remove particles adhering to the surface.

<Contents of substrate cleaning method>
Next, the content of the substrate cleaning method performed by the substrate cleaning apparatus 5 according to the first embodiment will be described with reference to FIGS. 2A to 2C. 2A to 2C are explanatory diagrams of the substrate cleaning method.

  As shown in FIG. 2A, in the first embodiment, a processing liquid containing a volatile component and forming a film on the wafer W (hereinafter referred to as “film forming processing liquid”) is used as the processing liquid. . Specifically, a film-forming treatment liquid (hereinafter referred to as “topcoat liquid”) for forming a topcoat film on the wafer W is used. The top coat film is a protective film that is applied to the upper surface of the resist film in order to prevent the immersion liquid from entering the resist film. The immersion liquid is a liquid used for immersion exposure in a lithography process, for example.

  As shown in FIG. 2A, the substrate cleaning apparatus 5 supplies the topcoat liquid onto the wafer W. The topcoat liquid supplied onto the wafer W causes volume shrinkage due to volatilization of volatile components contained therein. Furthermore, the topcoat liquid contains an acrylic resin having a property that the volume shrinks when solidified or cured, and the volume shrinkage of the topcoat liquid is also caused by the curing shrinkage of the acrylic resin. Here, “solidification” means solidification, and “curing” means that molecules are connected to each other to be polymerized (for example, crosslinking or polymerization).

  Then, the top coat liquid is solidified or cured while causing volume shrinkage to become a top coat film. At this time, the particles adhering to the pattern or the like are separated from the pattern or the like by the distortion (tensile force) generated by the volume contraction of the top coat liquid (see FIG. 2B).

  Since the topcoat liquid causes volume shrinkage due to volatilization of volatile components and curing shrinkage of acrylic resin, it has a large volume shrinkage rate compared to a film-forming treatment liquid containing only volatile components, and can strongly separate particles. . In particular, the acrylic resin has a larger cure shrinkage than other resins such as an epoxy resin, so that the topcoat liquid is effective in that it gives a tensile force to the particles.

  Thereafter, the substrate cleaning apparatus 5 removes the top coat film from the wafer W by dissolving the top coat film by supplying a removal liquid for dissolving the top coat film onto the top coat film. Thereby, the particles are removed from the wafer W together with the top coat film.

  The top coat film swells when dissolved by the removal liquid. For this reason, according to the substrate cleaning method according to the first embodiment, particles can be strongly separated from the pattern or the like not only by volume shrinkage due to volatilization of the topcoat film but also by volume expansion due to swelling of the topcoat film. .

  As described above, in the first embodiment, particles are removed by using the volume change of the film-forming treatment liquid. Thereby, compared with the particle removal using the conventional physical force, since a particle can be removed with a weak force, a pattern collapse can be suppressed. Further, since particle removal is performed without using a chemical action, erosion of the underlying film due to an etching action or the like can be suppressed. Therefore, according to the substrate cleaning method according to the first embodiment, particles attached to the wafer W can be removed while suppressing pattern collapse and erosion of the base film. The top coat film is completely removed from the wafer W without being subjected to pattern exposure after being formed on the wafer W.

  In addition, according to the substrate cleaning method according to the first embodiment, particles having a small particle diameter and particles that have entered a gap between patterns, which were difficult to remove by the substrate cleaning method using physical force, are easily removed. be able to.

  In the first embodiment, the removal efficiency of particles is increased by using an alkaline removal liquid. Specifically, an alkali developer is used as the remover. The alkali developer may contain at least one of ammonia, tetramethylammonium hydroxide (TMAH), and an aqueous choline solution, for example.

  By supplying the alkaline developer, a zeta potential having the same polarity (here, minus) is generated on the surface of the wafer W or pattern and the surface of the particle, as shown in FIG. 2C. Particles separated from the wafer W or the like due to a change in the volume of the top coat liquid are repelled from the wafer W or the like by being charged to a zeta potential having the same polarity as the wafer W or the like. Thereby, reattachment of particles to the wafer W or the like is prevented.

  As described above, after the particles are separated from the wafer W or the like by using the volume shrinkage of the top coat liquid, an alkali developer is supplied to dissolve the top coat film and dissolve the top coat film with the same polarity zeta as the particles. Generate a potential. Thereby, since the reattachment of particles is prevented, the particle removal efficiency can be further increased.

  Note that the film-forming treatment liquid such as the topcoat liquid supplied to the wafer W is finally removed from the wafer W. Therefore, the cleaned wafer W is in a state before the top coat liquid is applied, specifically, a state in which the circuit forming surface is exposed.

<Configuration and operation of substrate cleaning apparatus>
Next, the configuration and operation of the substrate cleaning apparatus 5 according to the first embodiment will be specifically described. FIG. 3 is a schematic diagram showing the configuration of the substrate cleaning apparatus 5 according to the first embodiment. In FIG. 3, only components necessary for explaining the features of the substrate cleaning apparatus 5 are shown, and descriptions of general components are omitted.

  As shown in FIG. 3, the substrate cleaning apparatus 5 includes a substrate holding unit 20, liquid supply units 30 </ b> A and 30 </ b> B, a recovery cup 40, and an airflow forming unit 50 in the chamber 10.

  The substrate holding unit 20 includes a rotation holding mechanism 21 that rotatably holds the wafer W, and a gas supply unit 22 that is inserted into the hollow portion 21 d of the rotation holding mechanism 21 and supplies gas to the lower surface of the wafer W.

  The rotation holding mechanism 21 is provided in the approximate center of the chamber 10. A holding unit 21 a that holds the wafer W from the side surface is provided on the upper surface of the rotation holding mechanism 21, and the wafer W is horizontally held in a state slightly separated from the upper surface of the rotation holding mechanism 21 by the holding unit 21 a. Is done. The holding unit 21 a is an example of a holding mechanism that holds the peripheral edge of the wafer W.

  The rotation holding mechanism 21 includes a drive mechanism 21b, and rotates around the vertical axis by the drive mechanism 21b. Specifically, the drive mechanism 21b includes a motor 21b1, a pulley 21b2 attached to the output shaft of the motor 21b1, and a belt 21b3 wound around the outer periphery of the pulley 21b2 and the rotation holding mechanism 21.

  The drive mechanism 21b rotates the pulley 21b2 by the rotation of the motor 21b1, and transmits the rotation of the pulley 21b2 to the rotation holding mechanism 21 by the belt 21b3, thereby rotating the rotation holding mechanism 21 around the vertical axis. Then, when the rotation holding mechanism 21 rotates, the wafer W held by the rotation holding mechanism 21 rotates integrally with the rotation holding mechanism 21. The rotation holding mechanism 21 is rotatably supported by the chamber 10 and the recovery cup 40 via a bearing 21c.

  The gas supply unit 22 is a long member inserted through a hollow portion 21 d formed in the center of the rotation holding mechanism 21. A flow path 22 a is formed inside the gas supply unit 22. The N2 supply source 7a is connected to the flow path 22a via the valve 8a. The gas supply unit 22 supplies N2 gas supplied from the N2 supply source 7a to the lower surface of the wafer W via the valve 8a and the flow path 22a.

  Here, the N2 gas supplied through the valve 8a is a high-temperature (for example, about 90 ° C.) N2 gas, and is used for a volatilization promoting process described later.

  The gas supply unit 22 is also used when the wafer W is transferred. Specifically, an elevating mechanism 22 c that moves the gas supply unit 22 in the vertical direction is provided at the base end of the gas supply unit 22. A support pin 22 d for supporting the wafer W is provided on the upper surface of the gas supply unit 22.

  When the substrate holding unit 20 receives the wafer W from the substrate transfer device 3a (see FIG. 1), the substrate holding unit 20 places the wafer W on the upper side of the support pins 22d in a state where the gas supply unit 22 is lifted using the lifting mechanism 22c. Place. Thereafter, the substrate holding unit 20 lowers the gas supply unit 22 to a predetermined position, and then transfers the wafer W to the holding unit 21 a of the rotation holding mechanism 21. Further, when the processed wafer W is transferred to the substrate transfer device 3a, the substrate holding unit 20 raises the gas supply unit 22 using the lifting mechanism 22c, and the wafer W held by the holding unit 21a is supported by the support pins. 22d. Then, the substrate holding unit 20 passes the wafer W placed on the support pins 22d to the substrate transfer device 3a.

  The liquid supply units 30 </ b> A and 30 </ b> B move from the outside of the wafer W to above the wafer W and supply the processing liquid toward the upper surface of the wafer W held by the substrate holding unit 20. The liquid supply unit 30A includes nozzles 31A and 31D, an arm 32A that horizontally supports the nozzles 31A and 31D, and a turning lift mechanism 33A that turns and lifts the arm 32A. The liquid supply unit 30B includes nozzles 31B and 31E, an arm 32B that horizontally supports the nozzles 31B and 31E, and a turning lift mechanism 33B that turns and lifts the arm 32B.

  The liquid supply unit 30A supplies a top coat liquid, which is a film forming process liquid, to the wafer W from the nozzle 31A, and uses MIBC (4-methyl-2-pentanol) as a solvent having an affinity for the top coat liquid. Supply from nozzle 31D. Specifically, a film forming processing liquid supply source 7b is connected to the nozzle 31A via a valve 8b, and the topcoat liquid supplied from the film forming processing liquid supply source 7b is transferred from the nozzle 31A onto the wafer W. To be supplied. Also, a solvent supply source 7h is connected to the nozzle 31D (corresponding to the “solvent supply unit”) via a valve 8h, and MIBC supplied from the solvent supply source 7h is supplied onto the wafer W from the nozzle 31D. .

  MIBC is contained in the topcoat solution and has an affinity for the topcoat solution. In addition, as a solvent having an affinity for the top coat liquid other than MIBC, for example, PGME (propylene glycol monomethyl ether), PGMEA (propylene glycol monomethyl ether acetate), or the like may be used.

  The liquid supply unit 30B supplies an alkaline developer as a removal liquid from the nozzle 31B to the wafer W, and supplies CDIW used for the rinsing process from the nozzle 31E. Specifically, a removal liquid supply source 7c is connected to the nozzle 31B via a valve 8c, and an alkaline developer supplied from the removal liquid supply source 7c is supplied onto the wafer W from the nozzle 31B. Further, a CDIW supply source 7d is connected to the nozzle 31E via a valve 8d, and the CDIW supplied from the CDIW supply source 7d is supplied onto the wafer W from the nozzle 31E. CDIW is pure water at room temperature (about 23 to 25 degrees).

  Here, the dedicated nozzles 31A, 31D, 31B, and 31E are provided for each processing liquid, but the nozzles may be shared by a plurality of processing liquids. For example, one nozzle may be provided on the arm 32A (see FIG. 3), and the topcoat liquid and MIBC may be selectively supplied from the nozzle. Similarly, one nozzle may be provided on the arm 32B, and the alkali developer and CDIW may be selectively supplied from the nozzle. However, when the nozzle is shared, for example, when it is not desired to mix the processing liquids, a process of once discharging the processing liquid remaining in the nozzles and the pipes is required, and the processing liquid is consumed wastefully. On the other hand, if the dedicated nozzles 31A, 31D, 31B, and 31E are provided, the process liquid is not required to be discharged as described above, so that the process liquid is not wasted.

  The collection cup 40 is disposed so as to surround the rotation holding mechanism 21 in order to prevent the treatment liquid from being scattered around. A drain port 41 is formed at the bottom of the recovery cup 40, and the processing liquid collected by the recovery cup 40 is discharged from the drain port 41 to the outside of the substrate cleaning apparatus 5. Further, an exhaust port 42 is formed at the bottom of the recovery cup 40, and N2 gas supplied by the gas supply unit 22 or gas supplied into the substrate cleaning apparatus 5 from the airflow forming unit 50 described later is applied thereto. The gas is discharged from the exhaust port 42 to the outside of the substrate cleaning apparatus 5.

  The drain port 41 is provided with a waste liquid line 12a and a recovery line 12b, and these lines 12a and 12b can be switched by a switching valve 15. The substrate cleaning apparatus 5 uses the switching valve 15 to switch between these lines 12a and 12b, so that the top coat liquid removed from the wafer W is discharged to the waste liquid line 12a, and the reusable alkali removal liquid is used. Each can be discharged to the recovery line 12b.

  An exhaust port 11 is formed at the bottom of the chamber 10, and a pressure reducing device 9 is connected to the exhaust port 11. The decompression device 9 is, for example, a vacuum pump, and the inside of the chamber 10 is decompressed by intake air.

  The air flow forming unit 50 is attached to the ceiling of the chamber 10 and is an air flow generating unit that forms a down flow in the chamber 10. Specifically, the airflow forming unit 50 includes a downflow gas supply pipe 51 and a buffer chamber 52 communicating with the downflow gas supply pipe 51. The downflow gas supply pipe 51 is connected to a downflow gas supply source (not shown). In addition, a plurality of communication ports 52 a that communicate the buffer chamber 52 and the inside of the chamber 10 are formed at the bottom of the buffer chamber 52.

  The airflow forming unit 50 supplies downflow gas (for example, clean gas or dry air) to the buffer chamber 52 via the downflow gas supply pipe 51. Then, the airflow forming unit 50 supplies the downflow gas supplied to the buffer chamber 52 into the chamber 10 through the plurality of communication ports 52a. Thereby, a down flow is formed in the chamber 10. The downflow formed in the chamber 10 is discharged from the exhaust port 42 and the exhaust port 11 to the outside of the substrate cleaning apparatus 5.

  Next, a specific operation of the substrate cleaning apparatus 5 will be described. FIG. 4 is a flowchart showing a processing procedure of the substrate cleaning process executed by the substrate cleaning apparatus 5. 5A to 5F are operation explanatory views of the substrate cleaning apparatus 5. Specifically, FIG. 5A and FIG. 5B show an operation example of the film forming process liquid supply process (step S103) in FIG. 4, and FIG. 5C shows an operation example of the volatilization promotion process (step S104) in FIG. Is shown. 5D shows an operation example of the removal liquid supply process (step S105) in FIG. 4, FIG. 5E shows an operation example of the rinse process (step S106) in FIG. 4, and FIG. 5F shows a drying process (step S105) in FIG. An operation example of step S107) is shown. Each processing procedure shown in FIG. 4 is performed based on the control of the control device 6.

  As shown in FIG. 4, in the substrate cleaning apparatus 5, first, a substrate carry-in process is performed (step S101). In the substrate carrying-in process, after the substrate transfer device 3a places the wafer W on the support pins 22d of the gas supply unit 22, the holding unit 21a of the rotation holding mechanism 21 holds the wafer W. At this time, the wafer W is held by the holding unit 21a with the circuit formation surface facing upward. Thereafter, the rotation holding mechanism 21 is rotated by the drive mechanism 21b. As a result, the wafer W rotates together with the rotation holding mechanism 21 while being held horizontally by the rotation holding mechanism 21.

  Subsequently, in the substrate cleaning apparatus 5, a solvent supply process is performed (step S102). The solvent supply process is a process of supplying to the wafer W MIBC having an affinity for the topcoat liquid before supplying the topcoat liquid, which is a film forming processing liquid, to the wafer W.

  Specifically, the nozzle 31D of the liquid supply unit 30A is positioned above the center of the wafer W, and then the MIBC is supplied from the nozzle 31D to the upper surface of the wafer W. The MIBC supplied to the upper surface of the wafer W is spread on the upper surface of the wafer W by centrifugal force accompanying the rotation of the wafer W.

  In this way, by spreading MIBC having an affinity for the top coat liquid on the wafer W in advance, the top coat liquid can easily spread on the upper surface of the wafer W in the film forming process liquid supply process described later. , It becomes easy to enter the gap between the patterns. Therefore, it is possible to reduce the amount of the top coat liquid used and more reliably remove particles that have entered the gaps in the pattern. In addition, the processing time of the film forming process liquid supply process can be shortened.

  As described above, when it is desired to efficiently spread the top coat film on the upper surface of the wafer W in a short time, it is preferable to perform the above-described solvent supply process. The solvent supply process does not necessarily need to be performed.

  In the solvent supply process, the drain port 41 of the recovery cup 40 (see FIG. 3) is connected to the recovery line 12b. Thereby, the MIBC scattered from the wafer W by the centrifugal force is discharged from the drain port 41 of the recovery cup 40 to the recovery line 12b through the switching valve 15.

  Subsequently, in the substrate cleaning apparatus 5, a film forming process liquid supply process is performed (step S103). In the film forming process liquid supply process, the nozzle 31A of the liquid supply unit 30A is positioned above the center of the wafer W. After that, as shown in FIG. 5A, a top coat liquid, which is a film-forming treatment liquid, is supplied from the nozzle 31A to the upper surface of the wafer W, which is a circuit formation surface on which no resist film is formed.

  The top coat liquid supplied to the upper surface of the wafer W is spread on the upper surface of the wafer W by centrifugal force accompanying the rotation of the wafer W. Thereby, as shown in FIG. 5B, a liquid film of the topcoat liquid is formed on the entire upper surface of the wafer W. When the film forming process liquid supply process is completed, the nozzle 31 </ b> A moves to the outside of the wafer W.

  In the film forming process liquid supply process, the drain port 41 of the recovery cup 40 (see FIG. 3) is connected to the waste liquid line 12a. Thereby, the top coat liquid splashed from the wafer W due to the centrifugal force is discharged from the drain port 41 of the recovery cup 40 to the waste liquid line 12a through the switching valve 15.

  Subsequently, the substrate cleaning apparatus 5 performs a volatilization promoting process (step S104). The volatilization promotion process is a process for promoting the volatilization of volatile components contained in the top coat liquid that forms a liquid film on the entire upper surface of the wafer W. Specifically, as shown in FIG. 5C, when the valve 8a (see FIG. 3) is opened for a predetermined time, high-temperature N 2 gas is supplied from the gas supply unit 22 to the lower surface of the rotating wafer W. Thereby, the topcoat liquid is heated together with the wafer W, and the volatilization of the volatile components is promoted.

  Further, the inside of the chamber 10 is decompressed by the decompression device 9 (see FIG. 3). Also by this, volatilization of the volatile component can be promoted. Further, downflow gas is supplied from the airflow forming unit 50 during the substrate cleaning process. The volatilization of the volatile component can also be promoted by reducing the humidity in the chamber 10 with the downflow gas.

  When the volatile component volatilizes, the top coat liquid solidifies or cures while shrinking in volume, forming a top coat film. Thereby, the particles adhering to the wafer W etc. are separated from the wafer W etc.

  As described above, the substrate cleaning apparatus 5 can shorten the time until the film-forming treatment liquid is solidified or cured by promoting the volatilization of the volatile components contained in the film-forming treatment liquid. In addition, heating the wafer W facilitates shrinkage hardening of the synthetic resin contained in the film-forming treatment liquid. Therefore, compared with the case where the wafer W is not heated, the shrinkage rate of the film-forming treatment liquid is further increased. Can be increased. The gas supply unit 22, the decompression device 9, and the airflow forming unit 50 are examples of the “volatilization promoting unit”.

  Here, an example in which the substrate cleaning apparatus 5 performs the volatilization promoting process has been described, but the volatilization promoting process can be omitted. That is, the substrate cleaning device 5 may be kept on standby until the topcoat liquid is naturally solidified or cured. Also, volatilization of the top coat liquid is promoted by stopping the rotation of the wafer W or rotating the wafer W at a rotation speed that does not expose the surface of the wafer W by shaking the top coat liquid. You may let them.

  Subsequently, the substrate cleaning apparatus 5 performs a removal liquid supply process (step S105). In the removal liquid supply process, the nozzle 31B is positioned above the center of the wafer W as shown in FIG. Thereafter, the valve 8c (see FIG. 3) is opened for a predetermined time, so that the alkaline developer as the removal liquid is supplied onto the rotating wafer W from the nozzle 31B of the liquid supply unit 30B. Thereby, the topcoat film formed on the wafer W is dissolved and removed.

  At this time, since the zeta potential having the same polarity is generated in the wafer W and the like and the particles, the wafer W and the particles are repelled and the reattachment of the particles to the wafer W and the like is prevented.

  In the removal liquid supply process, the drain port 41 of the recovery cup 40 (see FIG. 3) is connected to the recovery line 12b. As a result, the removal liquid splashed from the wafer W due to the centrifugal force is discharged from the drain port 41 of the recovery cup 40 to the recovery line 12b via the switching valve 15. The removal liquid discharged to the recovery line 12b is reused.

  The drain port 41 is connected to the waste liquid line 12a for a predetermined time after the supply of the removal liquid is started until the top coat film is sufficiently removed, and then the drain port 41 is connected to the recovery line 12b. You may make it connect. Thereby, it can prevent that a topcoat film | membrane mixes in the removal liquid to recycle.

  Subsequently, in the substrate cleaning apparatus 5, the top surface of the wafer W is rinsed with CDIW (step S106). In the rinsing process, the nozzle 31E is positioned above the center of the wafer W as shown in FIG. 5E. Thereafter, the valve 8d (see FIG. 3) is opened for a predetermined time, so that CDIW is supplied from the nozzle 31E of the liquid supply unit 30B to the upper surface of the rotating wafer W, and the top coat film remaining on the wafer W and alkali development are developed. The liquid is washed away.

  Specifically, the CDIW supplied onto the wafer W is scattered outside the wafer W while diffusing on the wafer W by the rotation of the wafer W. By this rinsing process, the dissolved top coat film and particles floating in the alkaline developer are removed from the wafer W together with the CDIW. At this time, the inside of the chamber 10 can be quickly exhausted by the downflow formed by the airflow forming unit 50. When the rinsing process is completed, the nozzle 31E moves to the outside of the wafer W.

  Subsequently, in the substrate cleaning apparatus 5, a drying process is performed (step S107). In such a drying process, the CDIW remaining on the upper surface of the wafer W is shaken off by increasing the rotation speed of the wafer W for a predetermined time, and the wafer W is dried (see FIG. 5F). Thereafter, the rotation of the wafer W is stopped.

  Then, the substrate cleaning apparatus 5 performs a substrate carry-out process (step S108). In such substrate carry-out processing, the gas supply unit 22 is raised by the elevating mechanism 22c (see FIG. 3), and the wafer W held by the holding unit 21a is placed on the support pins 22d. Then, the wafer W placed on the support pins 22d is transferred to the substrate transfer device 3a. When the substrate carry-out process is completed, the substrate cleaning process for one wafer W is completed. The wafer W is unloaded from the substrate cleaning apparatus 5 with the circuit forming surface exposed.

  As described above, the substrate cleaning apparatus 5 according to the first embodiment includes the liquid supply unit 30A (corresponding to the first liquid supply unit) and the liquid supply unit 30B (corresponding to the second liquid supply unit). Prepare. The liquid supply unit 30A supplies the wafer W with a topcoat liquid that contains a volatile component and is a processing liquid for forming a film on the wafer W. The liquid supply unit 30B is a removing liquid that is supplied to the wafer W by the liquid supply unit 30A and dissolves all of the topcoat liquid in the topcoat liquid that is solidified or cured on the wafer W by volatilization of volatile components. Supply alkaline developer. Therefore, according to the first embodiment, particles attached to the wafer W can be removed while suppressing pattern collapse and erosion of the underlying film.

  Moreover, the substrate cleaning apparatus 5 according to the first embodiment uses an alkaline removal solution. Thereby, a zeta potential having the same polarity is generated between the wafer W and the particles and the particles are prevented from reattaching, so that the particle removal efficiency can be increased.

<Comparison with cleaning method using physical force>
Here, a comparison result between the two-fluid cleaning which is a cleaning method using physical force and the substrate cleaning method according to the first embodiment (hereinafter referred to as “the main cleaning method”) will be described. First, comparison conditions will be described with reference to FIGS. 12A and 12B. FIG. 12A and FIG. 12B are explanatory diagrams of comparative conditions between this cleaning method and two-fluid cleaning.

  As shown in FIGS. 12A and 12B, a wafer without a pattern (see FIG. 12A) and a wafer with a pattern in which patterns having a height of 0.5 μm and a width of 0.5 μm are formed at intervals of 1.0 μm (see FIG. 12B). ) And the two-fluid cleaning and the main cleaning method were compared, the particle removal rate by each cleaning method was compared. The particle diameter of the particles is 200 nm.

  Each cleaning method was performed under two conditions of “no damage condition” and “damage condition”. The “no damage condition” is a predetermined condition in which a thermal oxide film having a thickness of 2 nm is formed on a wafer and a sample pattern having a height of 100 nm and a width of 45 nm is formed on the thermal oxide film so that the sample pattern is not collapsed. It is the condition where cleaning was performed with the power of. The “damaged condition” refers to a condition in which cleaning is performed with a predetermined force that causes the sample pattern to collapse.

  Next, the comparison results are shown in FIG. FIG. 13 is a diagram showing a comparison result between this cleaning method and two-fluid cleaning. In FIG. 13, the particle removal rate for a wafer without a pattern is indicated by hatching with a left-downward diagonal line, and the particle removal rate for a wafer with pattern is indicated by hatching with a downward-sloping diagonal line. In this cleaning method, the sample pattern did not collapse. For this reason, only the result of “no damage condition” is shown for this cleaning method.

  As shown in FIG. 13, the particle removal rates of the main cleaning method, the two-fluid cleaning (no damage condition) and the two-fluid cleaning (damage condition) on the pattern-less wafer are both close to 100%. There was no significant difference in the method.

  On the other hand, the particle removal rate of the two-fluid cleaning with respect to the wafer with the pattern was about 17% under the condition without damage and about 32% under the condition with the damage, which was significantly reduced compared with the wafer without the pattern. As described above, the particle removal rate of the wafer with the pattern is greatly reduced as compared with the case of the wafer without the pattern, so that it is difficult to remove the particles entering the gap between the patterns by the two-fluid cleaning.

  On the other hand, this cleaning method showed a value close to 100% for a wafer with a pattern as in the case of a wafer without a pattern. Thus, since there was almost no change in the particle removal rate between the non-patterned wafer and the patterned wafer, it can be seen that the particles entering the gap between the patterns were appropriately removed by this cleaning method.

  As described above, according to the present cleaning method, it is not only difficult to collapse the patterns, but also particles that have entered between the patterns can be appropriately removed as compared with the two-fluid cleaning.

<Comparison with chemical cleaning method>
Next, a comparison between chemical cleaning with SC1 (ammonia peroxide), which is a cleaning method using chemical action, and this cleaning method will be described. 14 and 15 are diagrams showing comparison results between this cleaning method and chemical cleaning. FIG. 14 shows a comparison result of particle removal rates, and FIG. 15 shows a comparison result of film loss. Film loss is the erosion depth of a thermal oxide film that is a base film formed on a wafer.

  In addition, about chemical | medical solution washing | cleaning, SC1 which mixed ammonia, water, and hydrogen peroxide solution in the ratio of 1: 2: 40 was used, respectively, and it wash | cleaned on the conditions of temperature 60 degreeC and supply time 600 second. Moreover, about this washing | cleaning method, after supplying a topcoat liquid, after performing a volatilization acceleration process, supply of the alkali developing solution was performed for 10 second. The wafer with a pattern shown in FIG. 12B was used as the wafer.

  As shown in FIG. 14, the particle removal rate by chemical cleaning is 97.5%, which is slightly lower than the particle removal rate (98.9%) of this cleaning method. In contrast, it can be seen that the particles that have entered the gaps in the pattern are appropriately removed.

  On the other hand, as shown in FIG. 15, as a result of chemical cleaning, a 7 A (angstrom) film loss occurred, but no film loss occurred even when this cleaning method was performed. Thus, it can be seen that this cleaning method can remove particles that have entered the gaps of the pattern without eroding the underlying film.

  As described above, according to the present cleaning method, it is possible to appropriately remove particles that have entered the gaps of the pattern while preventing pattern collapse and erosion of the base film, and thus a cleaning method using physical force. And more effective than cleaning methods using chemical action.

  In addition, the substrate cleaning apparatus 5 may apply the film-forming treatment liquid to the wafer W repeatedly. For example, the substrate cleaning apparatus 5 may perform the processing from step S105 onward after repeating the film forming process liquid supply processing in step S103 and the volatilization promotion processing in step S104 shown in FIG. Further, the substrate cleaning apparatus 5 may perform the processing after step S106 after repeating the processing of steps S102 to S105 shown in FIG. 4 a plurality of times.

(Second Embodiment)
By the way, in the first embodiment described above, the volatile component contained in the topcoat liquid is obtained by heating the topcoat liquid, reducing the humidity in the chamber 10, or reducing the pressure in the chamber 10. It was decided to promote volatilization. However, the volatilization promoting process is not limited to that described in the first embodiment. Hereinafter, another example of the volatilization promoting process will be described with reference to FIG. FIG. 6 is a schematic diagram illustrating a configuration of the substrate cleaning apparatus according to the second embodiment. In the following description, parts that are the same as those already described are given the same reference numerals as those already described, and redundant descriptions are omitted.

  The substrate cleaning apparatus 5A according to the second embodiment includes an ultraviolet irradiation unit 60 in addition to the components included in the substrate cleaning apparatus 5 according to the first embodiment. The ultraviolet irradiation unit 60 is, for example, a UV (Ultra Violet) lamp, is disposed above the wafer W, and irradiates ultraviolet rays from above the wafer W toward the upper surface of the wafer W. Thereby, the topcoat liquid is activated and the volatilization of the volatile components is promoted.

  As described above, the substrate cleaning apparatus 5A may perform the process of promoting the volatilization of the volatile component by irradiating the top coat liquid with ultraviolet rays as the volatilization promoting process. The ultraviolet irradiation unit 60 is an example of a volatilization promoting unit.

  In addition, it is preferable to arrange | position the ultraviolet irradiation part 60 in the position higher than the nozzle 31A, 31D, 31B, 31E of liquid supply part 30A, 30B so that the process by liquid supply part 30A, 30B may not be inhibited. Alternatively, the ultraviolet irradiation unit 60 may be configured to be movable so as to be positioned above the wafer W only when the volatilization promotion process is performed.

(Third embodiment)
The configuration of the substrate cleaning apparatus is not limited to the configuration shown in each embodiment described above. Therefore, hereinafter, another configuration of the substrate cleaning apparatus will be described with reference to FIG. FIG. 7 is a schematic diagram illustrating a configuration of a substrate cleaning apparatus according to the third embodiment. In the following description, parts that are the same as those already described are given the same reference numerals as those already described, and redundant descriptions are omitted.

  As shown in FIG. 7, the substrate cleaning apparatus 5B according to the third embodiment includes a chamber 10 instead of the chamber 10, the substrate holding unit 20, and the recovery cup 40 included in the substrate cleaning apparatus 5 according to the first embodiment. ', Equipped with a substrate holding part 20' and a recovery cup 40 '. Further, the substrate cleaning apparatus 5B includes a top plate 213 that covers the upper portion of the wafer W held by the holding member 212.

  The substrate holding unit 20 ′ includes a rotation holding mechanism 21 ′ that rotatably holds the wafer W, and an under plate 22 ′ that covers the lower side of the wafer W held by the rotation holding mechanism 21 ′.

  The rotation holding mechanism 21 ′ includes a main body portion 211 through which the under plate 22 ′ is inserted, and a holding member 212 that is provided in the main body portion 211 and holds the wafer W while being separated from the under plate 22 ′.

  The holding member 212 includes a plurality of (for example, three) support pins 212a that support the lower surface of the wafer W, and horizontally supports the wafer W by causing the support pins 212a to support the lower surface of the wafer W. The wafer W is supported by the support pins 212a with the circuit formation surface facing upward.

  The top plate 213 is formed in a size that covers the upper surface of the wafer W, and an opening 213a for allowing the processing liquid supplied by the liquid supply units 30A and 30B to pass therethrough is provided at the center. When supplying the processing liquid to the wafer W, the processing liquid is supplied from the opening 213 a to the center of the wafer W. The top plate 213 includes an arm 213b that horizontally supports the top plate 213, and a drive mechanism 213c that turns and lifts the arm 213b.

  When the drive mechanism 213c raises the arm 213b, the top plate 213 rises and moves away from the wafer W. On the other hand, when the drive mechanism 213c lowers the arm 213b, the top plate 213 is held at a position close to the wafer W. As described above, the top plate 213 is close to the upper surface of the wafer W and covers the upper portion of the wafer W (hereinafter referred to as “processing position”), and is spaced from the upper surface of the wafer W to open the upper portion of the wafer W. It is possible to move between positions (hereinafter referred to as “retraction positions”).

  The rotation holding mechanism 21 ′ is rotatably supported by the chamber 10 ′ and the recovery cup 40 ′ via a bearing 21c and vertically by the drive mechanism 21b, similarly to the rotation holding mechanism 21 according to the first embodiment. Rotate around an axis.

  The under plate 22 ′ is a member formed to have a size that covers the lower surface of the wafer W held by the rotation holding mechanism 21 ′. A channel 22e is formed inside the under plate 22 '. The flow path 22e is connected to the film-forming treatment liquid supply source 7b via the valve 8e and to the solvent supply source 7h via the valve 8i. The under plate 22 'supplies the top coat liquid and MIBC respectively supplied from these supply sources to the lower surface of the wafer W through the flow path 22e.

  Further, a CDIW supply source 7d is connected to the flow path 22e via a valve 8f, and a removal liquid supply source 7c is connected via a valve 8g. The under plate 22 'can also supply the CDIW and the alkali developer supplied from these supply sources to the lower surface of the wafer W through the flow path 22e.

  An elevating mechanism 22c for moving the under plate 22 'in the vertical direction is provided at the base end portion of the under plate 22'. By such an elevating mechanism 22c, the under plate 22 ′ is described as a position close to the lower surface of the wafer W (hereinafter referred to as “processing position”) and a position separated from the lower surface of the wafer W (hereinafter referred to as “retreat position”). The position can be changed.

  In the third embodiment, the decompression device 9 is connected to the exhaust port 42 of the recovery cup 40 ′ instead of the exhaust port 11 of the chamber 10. The decompression device 9 places the processing space in a decompressed state by performing suction through the exhaust port 42 in the processing space formed by the recovery cup 40 ′ and the top plate 213 in the substrate cleaning process described later.

  Next, the contents of the substrate cleaning process performed by the substrate cleaning apparatus 5B according to the third embodiment will be described. FIG. 8 is an explanatory diagram of the operation of the substrate cleaning apparatus 5B according to the third embodiment.

  As shown in FIG. 8, the top plate 213 and the under plate 22 'are located at the processing positions. That is, the top plate 213 is positioned near the upper surface of the wafer W so as to cover the upper side of the wafer W, and the under plate 22 ′ is positioned near the lower surface of the wafer W. Thereby, a narrow gap of about 1 mm is formed between the top plate 213 and the upper surface of the wafer W and between the under plate 22 ′ and the lower surface of the wafer W.

  Subsequently, when the main body 211 is rotated by the drive mechanism 21b (see FIG. 7), the holding member 212 and the wafer W are rotated. Then, after the nozzle 31D is positioned above the center of the wafer W, MIBC is supplied from the nozzle 31D to the upper surface of the wafer W, and MIBC is supplied from the under plate 22 'to the lower surface of the wafer W.

  The MIBCs respectively supplied from the nozzle 31D and the under plate 22 'are diffused in the outer peripheral direction of the wafer W by the centrifugal force generated by the rotation of the wafer W. As a result, MIBC is deposited on the upper surface of the wafer W, and the gap formed between the under plate 22 ′ and the lower surface of the wafer W is filled with MIBC.

  Subsequently, after the nozzle 31A is positioned above the center of the wafer W, the topcoat liquid is supplied from the nozzle 31A to the upper surface of the wafer W, and the topcoat liquid is supplied from the under plate 22 ′ to the lower surface of the wafer W. .

  The top coat liquid respectively supplied from the nozzle 31 </ b> A and the under plate 22 ′ diffuses in the outer circumferential direction of the wafer W due to the centrifugal force generated by the rotation of the wafer W. As a result, the top coat liquid is deposited on the upper surface of the wafer W, and the gap formed between the under plate 22 ′ and the lower surface of the wafer W is filled with the top coat liquid. When this processing is completed, the nozzle 31A moves outward of the wafer W.

  The under plate 22 ′ is provided with a heating unit 23, and the volatile component promoting process is performed by the heating unit 23. That is, the top coat liquid is heated by the heating unit 23. The heating temperature at this time is 90 degreeC, for example. Thereby, volatilization of the volatile component contained in the topcoat liquid is promoted. Thus, the heating unit 23 is an example of a volatilization promoting unit.

  Further, as the volatilization promoting process, a process of operating the decompression device 9 to bring the chamber 10 'into a decompressed state is also performed. In the third embodiment, a relatively narrow processing space is formed by the recovery cup 40 ′ and the top plate 213. The decompression device 9 easily reduces the pressure in the processing space by performing intake air in the processing space through the exhaust port 42.

  Further, the downflow gas supplied from the airflow forming unit 50 is supplied to the processing space through the opening 213 a formed in the top plate 213. For this reason, volatilization of the volatile component can be promoted also by the humidity in the processing space being lowered by the downflow gas. In addition, although the example in the case where downflow gas is supplied from the airflow formation unit 50 was shown here, the downflow gas is, for example, the nozzle 31A (or nozzle 31B) of the liquid supply unit 30A (or liquid supply unit 30B). ).

  Subsequently, after the nozzle 31B is positioned above the center of the wafer W, an alkaline developer as a removal liquid is supplied from the nozzle 31B and the under plate 22 'to the upper and lower surfaces of the wafer W. The alkaline developer supplied on the wafer W is diffused on the wafer W by the rotation of the wafer W, and dissolves the top coat film formed on the wafer W. Scatter toward At this time, by moving the top plate 213 to the retracted position and opening the upper portion of the wafer W, the inside of the chamber 10 can be quickly exhausted by the down flow.

  Subsequently, after the nozzle 31E is positioned above the center of the wafer W, CDIW is supplied to the upper and lower surfaces of the wafer W from the nozzle 31E and the under plate 22 '. As a result, the topcoat film and the alkali developer remaining on the wafer W are washed away from the wafer W by the CDIW. When such processing is completed, the nozzle 31E moves outward of the wafer W.

  Thereafter, similarly to the substrate cleaning apparatus 5 according to the first embodiment, the drying process and the substrate carry-out process are performed to complete the substrate cleaning process.

  As described above, the substrate cleaning apparatus 5B according to the third embodiment includes the top plate 213 which covers the upper surface of the wafer W and has the opening 213a through which the top coat liquid supplied by the liquid supply unit 30A passes. Prepare. The liquid supply unit 30 </ b> A supplies the topcoat liquid to the wafer W through the opening 213 a formed in the top plate 213.

  The substrate cleaning apparatus 5B according to the third embodiment includes an under plate 22 ′ that covers the lower surface of the wafer W and is provided with a heating unit 23 for heating the top coat liquid supplied to the wafer W. . Accordingly, the substrate cleaning apparatus 5B can perform the volatilization promoting process using the heating unit 23 provided in the under plate 22 '.

  Note that the liquid supplied between the under plate 22 ′ and the lower surface of the wafer W is not limited to the top coat liquid, and may be pure water or the like. Then, the substrate cleaning apparatus 5B deposits the top coat liquid on the wafer W, and then supplies HDIW (pure water of about 90 ° C.) to the lower surface of the wafer W from the under plate 22 ′. It is good also as promoting volatilization of the volatile component contained in a topcoat liquid by heating.

  In addition, after the topcoat liquid is deposited, the topcoat liquid is heated via the wafer W by supplying a high-temperature gas (such as N 2 gas) between the under plate 22 ′ and the lower surface of the wafer W. It may be. Alternatively, the under plate 22 ′ (corresponding to a heating plate) including the heating unit 23 may be brought into contact with the wafer W so that the under plate 22 ′ directly heats the wafer W.

  Further, a UV irradiation unit may be provided below the top plate 213. Thereby, similarly to 2nd Embodiment, a topcoat liquid can be activated by the ultraviolet-ray irradiated from a UV irradiation part, and volatilization of a volatile component can be accelerated | stimulated.

(Fourth embodiment)
Next, a substrate cleaning apparatus according to a fourth embodiment will be described with reference to FIG. FIG. 9 is a schematic diagram illustrating a configuration of a substrate cleaning apparatus according to the fourth embodiment.

  As shown in FIG. 9, the substrate cleaning apparatus 5C according to the fourth embodiment includes a liquid supply unit 30B ′ instead of the liquid supply unit 30B included in the substrate cleaning apparatus 5 (see FIG. 3).

  The liquid supply unit 30B 'further includes a nozzle 31C in addition to the nozzle 31B and the nozzle 31E. The nozzle 31 </ b> C is supported obliquely with respect to the arm 32 </ b> B, and is configured such that the discharge port faces the peripheral direction of the wafer W when the nozzle 31 </ b> B is positioned above the center of the wafer W. The nozzle 31C is an example of a third liquid supply unit.

  A removal liquid supply source 7c (see FIG. 3) is connected to the nozzle 31C via a valve (not shown). Then, the nozzle 31 </ b> C discharges the alkaline developer supplied from the removal liquid supply source 7 c in the peripheral direction of the wafer W. As a result, an alkaline developer having a flow rate and flow rate sufficient to clean the holding unit 21a is supplied to the holding unit 21a.

  The valve connected to the nozzle 31C is a valve different from the valve 8c (see FIG. 3) connected to the nozzle 31B. Therefore, the supply start timing and supply stop timing of the alkaline developer can be individually controlled by the nozzle 31B and the nozzle 31C. Since the other structure of the substrate cleaning apparatus 5C is the same as that of the substrate cleaning apparatus 5, description thereof is omitted here.

  The substrate cleaning apparatus 5C according to the fourth embodiment performs a cleaning process on the holding unit 21a using the liquid supply unit 30B 'under the control of the control device 6. Specifically, in the above-described removal liquid supply process (step S104 in FIG. 4), a valve and a valve 8c (not shown) connected to the nozzle 31C after the nozzle 31B is positioned above the center of the wafer W (see FIG. 3). Is released for a predetermined time, so that the alkaline developer as the removal liquid is supplied onto the rotating wafer W from the nozzle 31B and supplied to the holding portion 21a rotating from the nozzle 31C.

  Thereby, the topcoat film adhering to the holding part 21a is dissolved and removed from the holding part 21a. That is, the holding part 21a is cleaned.

  The valve connected to the nozzle 31C is closed before the valve 8c (see FIG. 3). Thereby, the supply of the alkaline developer from the nozzle 31C to the holding unit 21a stops before the supply of the alkaline developer from the nozzle 31B to the wafer W.

  Thereby, even if the top coat film adhering to the holding portion 21a is scattered on the wafer W by the alkali developer supplied from the nozzle 31C, the adhesion to the wafer W is prevented by the alkali developer supplied from the nozzle 31B. Can be washed away.

  As described above, according to the substrate cleaning apparatus 5C according to the fourth embodiment, since the nozzle 31C that supplies the alkaline developer to the holding unit 21a is further provided, the topcoat film attached to the holding unit 21a is formed. It can be removed, and the wafer W can be prevented from being stained or dusted.

  Here, an example is shown in which the supply of the alkaline developer from the nozzle 31C to the holding unit 21a is stopped before the supply of the alkaline developer from the nozzle 31B to the wafer W is stopped. The stop timing is not limited to this. For example, the supply of the alkaline developer from the nozzle 31C to the holding unit 21a may be stopped before the rinsing process is completed, that is, before the supply of CDIW from the nozzle 31B to the wafer W is stopped. Even in such a case, the top coat film scattered on the wafer W from the holding portion 21a can be washed away by the CDIW supplied from the nozzle 31B.

  As described above, the supply of the alkali developer from the nozzle 31C to the holding unit 21a may be stopped before the supply of the processing solution (alkaline developer or CDIW) from the nozzle 31B to the wafer W is stopped.

(Fifth embodiment)
Next, a substrate cleaning apparatus according to a fifth embodiment will be described. 10A and 10B are schematic views illustrating the configuration of the rotation holding mechanism according to the fifth embodiment.

  As shown in FIG. 10A, the substrate cleaning apparatus 5D according to the fifth embodiment includes a rotation holding mechanism 21 ″ instead of the rotation holding mechanism 21 included in the substrate cleaning apparatus 5 (see FIG. 3). The other configuration of the substrate cleaning apparatus 5D is the same as that of the substrate cleaning apparatus 5, and therefore the description thereof is omitted here.

  The rotation holding mechanism 21 '' replaces the holding unit 21a included in the rotation holding mechanism 21, and includes a first holding unit 21e that holds the wafer W and a second holding unit that can operate independently of the first holding unit 21e. Holding part 21f.

  A plurality of first holding portions 21e are provided at equal intervals along the circumferential direction of the wafer W, here three at 120 ° intervals, and are configured to be movable along the radial direction of the wafer W. . The second holding portions 21f are arranged at equal intervals between the first holding portions 21e, and are configured to be movable along the radial direction of the wafer W in the same manner as the first holding portions 21e.

  As described above, the substrate cleaning apparatus 5D according to the fifth embodiment includes the two holding units that can operate independently, and the wafer W can be changed using these.

  For example, FIG. 10A shows a state where the wafer W is held by the first holding unit 21e. In this state, after the second holding unit 21f is moved in the direction approaching the wafer W, the first holding unit 21e is moved in the direction away from the wafer W, so that the wafer W is moved as shown in FIG. The first holding unit 21e can be switched to the second holding unit 21f.

  Next, the timing for changing the wafer W will be described with reference to FIGS. 11A and 11B. FIG. 11A is a diagram showing the timing for changing the wafer W. FIG. FIG. 11B is a diagram illustrating another example of the timing for changing the wafer W.

  As shown in FIG. 11A, the change of the wafer W between the first holding unit 21e and the second holding unit 21f is performed at a predetermined timing during the removal liquid supply process (step S105 in FIG. 4). Specifically, after the start of the removal liquid supply process, the second holding unit is at a timing at which the top coat film is washed away to some extent by the alkaline developer and there is no risk of the top coat film adhering to the second holding unit 21f. 21 f is moved in a direction approaching the wafer W, and then the first holding unit 21 e is moved in a direction away from the wafer W.

  As described above, in the fifth embodiment, the wafer W is switched between the first holding unit 21e and the second holding unit 21f. For this reason, even if the top coat film is attached to the first holding unit 21e, the wafer W can be prevented from being soiled or dusted by switching to the second holding unit 21f. it can.

  Note that the change from the first holding unit 21e to the second holding unit 21f may be performed immediately after the end of the volatilization promotion process, as shown in FIG. 11B. Since the topcoat liquid is difficult to adhere to the second holding portion 21f when solidified, even if it is performed immediately after the completion of the volatilization promoting process, the wafer W can be prevented from being soiled or dusted.

  Further, the substrate cleaning apparatus 5D may include a nozzle for supplying an alkali removing liquid to the first holding unit 21e, as in the substrate cleaning apparatus 5C according to the fourth embodiment, and the first cleaning unit 5D may be configured using the nozzle. One holding part 21e may be periodically cleaned. Note that this cleaning process is preferably performed in a state where no wafer W exists in the chamber.

(Other embodiments)
By the way, in each embodiment mentioned above, the example in case the rotation holding mechanism is a mechanical chuck which hold | maintains the peripheral part of the wafer W was shown. However, the rotation holding mechanism is not limited to the mechanical chuck, and may be a vacuum chuck that holds the wafer W by suction.

  Further, the vacuum chuck may include a heating mechanism. Thereby, since the wafer W that has been sucked and held can be directly heated, volatilization of the volatile components contained in the topcoat liquid can be more effectively promoted.

  Further, a holding unit similar to the above-described holding units 21a, 21e, and 21f may be provided in the vacuum chuck, and the wafer W may be changed between the vacuum chuck and the holding unit. In such a case, in the film-forming treatment liquid supply process (step S103 in FIG. 4), a vacuum chuck that does not have a portion in contact with the upper surface of the wafer W and can spread the topcoat liquid on the entire upper surface of the wafer W is used. In the removal liquid supply process (step S105 in FIG. 4), it is preferable to use a holding unit that can easily clean the back surface of the wafer W. Therefore, after completion of the volatilization promoting process, it is preferable to change the vacuum chuck to the holding unit.

  By the way, although each embodiment mentioned above demonstrated the example in the case of using a topcoat liquid as a film-forming process liquid, the film-forming process liquid is not limited to a topcoat liquid.

  For example, the film-forming treatment liquid may be a treatment liquid containing a phenol resin. Since such a phenol resin also causes curing shrinkage in the same manner as the acrylic resin described above, it is effective in that it gives a tensile force to the particles as in the case of the top coat liquid.

  An example of the film-forming treatment liquid containing a phenol resin is a resist liquid. The resist solution is a film-forming treatment solution for forming a resist film on the wafer W. Specifically, the resist solution contains a novolac type phenol resin.

  Note that when a resist solution is used as the film-forming treatment solution, a thinner that can dissolve the resist solution may be used as the removal solution. When thinner is used as the removal liquid, the rinsing process after the removal liquid supply process can be omitted. In the case where a resist solution is used as the film-forming treatment solution, the removal solution may be supplied after performing an exposure process such as an overall exposure on the resist film formed on the wafer W. In such a case, the remover may be a developer or a thinner.

  The synthetic resin contained in the film-forming treatment liquid may be any resin that cures and shrinks, and is not limited to the above acrylic resin or phenol resin. For example, the synthetic resin contained in the film-forming treatment liquid is epoxy resin, melanin resin, urea resin, unsaturated polyester resin, alkyd resin, polyurethane, polyimide, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinyl acetate, Tetrafluoroethylene, acrylonitrile butadiene styrene resin, acrylonitrile styrene resin, polyamide, nylon, polyacetal, polycarbonate, modified polyphenylene ether, polybutylene terephthalate, polyethylene terephthalate, polyphenylene sulfide, polysulfone, polyether ether ketone, polyamide imide, etc. Good.

  Further, an antireflection film liquid may be used as the film-forming treatment liquid. The antireflection film liquid is a film forming treatment liquid for forming an antireflection film on the wafer W. The antireflection film is a protective film for reducing the surface reflection of the wafer W and increasing the transmittance. When such an antireflection film liquid is used as a film-forming treatment liquid, pure water (for example, CDIW or HDIW) that can dissolve the antireflection film liquid can be used as a removal liquid.

  In addition to the volatile component and the synthetic resin, the film-forming treatment liquid may further include a predetermined chemical solution that dissolves the wafer W, the material formed on the wafer W, or foreign matter adhering to the wafer W. Here, the “material formed on the wafer W” is, for example, a base film of the wafer W, and the “foreign matter adhering to the wafer W” is, for example, a particulate metallic contaminant (particle). . Examples of the “predetermined chemical solution” include hydrogen fluoride, ammonium fluoride, hydrochloric acid, sulfuric acid, hydrogen peroxide solution, phosphoric acid, acetic acid, nitric acid, and ammonium hydroxide. Since the base film and the surface of the particles are dissolved by these chemical solutions, the adhesion force of the particles is weakened, so that the particles can be easily removed.

  The “predetermined chemical solution” is used under the condition that the etching amount is small compared with the chemical solution in the normal chemical solution cleaning using chemical action. For this reason, it is possible to perform more effective particle removal while suppressing erosion to the base film as compared with normal chemical cleaning.

  Further, in each of the embodiments described above, an example in which an alkaline developer is used as the remover has been described. However, the remover may be a solution obtained by adding hydrogen peroxide to an alkali developer. Thus, by adding hydrogen peroxide water to the alkaline developer, surface roughness of the wafer surface due to the alkaline developer can be suppressed.

  The removal solution may be an organic solvent such as thinner, toluene, acetate esters, alcohols, glycols (propylene glycol monomethyl ether), or an acid developer such as acetic acid, formic acid, hydroxyacetic acid, etc. Also good.

  Furthermore, the removal liquid may further contain a surfactant. Since the surfactant has a function of weakening the surface tension, reattachment of particles to the wafer W or the like can be suppressed.

  Further, in each of the embodiments described above, the wafer W is rotated using the substrate holding unit that rotatably holds the wafer W, and a processing liquid such as a top coat is spread on the wafer W by the centrifugal force accompanying the rotation. It was. However, the present invention is not limited to this. For example, the processing liquid may be spread on the wafer W without rotating the wafer W by using a slit nozzle. In such a case, the substrate holder may not include a rotation mechanism.

  Further effects and modifications can be easily derived by those skilled in the art. Thus, the broader aspects of the present invention are not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications can be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

W wafer 5 Substrate cleaning device 6 Control device 9 Decompression device 10 Chamber 11 Exhaust port 20 Substrate holding unit 21 Rotation holding mechanism 22 Gas supply unit 30A, 30B Liquid supply unit 31A to 31E Nozzle 40 Recovery cup 41 Drain port 42 Exhaust port 50 Airflow forming unit 100 Substrate cleaning system

Claims (15)

A first liquid supply unit that supplies a processing liquid for forming a film on the substrate including a volatile component and a synthetic resin having a property of shrinking in volume when solidified or cured;
The supplied into the first liquid the substrate by supplying unit, a remover for removing any film of the treatment liquid to the film of the solidified or cured treatment liquid on the substrate by the volatile component volatilizes A second liquid supply unit for supplying,
Wherein the distortion caused by volume shrinkage of the synthetic resin, the particles attached to the pattern pattern when the first liquid is supplied from the supply unit film of the treatment liquid covering the pattern on the substrate is solidified or cured There away from the pattern in a state of being covered with the film of the processing liquid, the substrate cleaning apparatus. A substrate holder for holding the substrate;
The substrate cleaning apparatus according to claim 1, further comprising: a chamber that houses the first liquid supply unit, the second liquid supply unit, and the substrate holding unit. The substrate cleaning apparatus according to claim 2 , further comprising a heating mechanism that heats the substrate held by the substrate holding unit. The second liquid supply unit includes:
The substrate cleaning apparatus according to claim 1, wherein a rinsing liquid for removing the film of the processing liquid remaining on the substrate and the removing liquid from the substrate is supplied to the substrate.   The substrate cleaning apparatus according to claim 1, wherein the synthetic resin contained in the treatment liquid is an acrylic resin.   The substrate cleaning apparatus according to claim 1, wherein the synthetic resin contained in the treatment liquid is a phenol resin.   The substrate cleaning apparatus according to claim 6, wherein the phenol resin is a novolac phenol resin.   The substrate cleaning apparatus according to claim 1, wherein the removing liquid is an alkaline liquid.   The substrate cleaning apparatus according to claim 8, wherein the removing liquid includes at least one of ammonia, tetramethylammonium hydroxide, and an aqueous choline solution.   The substrate cleaning apparatus according to claim 1, wherein the removing liquid is an organic solvent. The substrate cleaning apparatus according to claim 1, further comprising a volatilization promoting unit that promotes volatilization of a volatile component contained in the processing liquid. The volatilization promoting part is
The substrate cleaning apparatus according to claim 11, wherein volatilization of the volatile component is promoted by heating the processing liquid. The volatilization promoting part is
The substrate cleaning apparatus according to claim 12, wherein the substrate is heated by supplying a high-temperature fluid to the lower surface of the substrate to promote volatilization of the volatile component. A first liquid supply step of supplying a treatment liquid for forming a film on the substrate including a volatile component and a synthetic resin having a property of shrinking in volume when solidified or cured;
The supplied to the substrate in the first liquid supply step, the removing solution to remove any film of the treatment liquid to the film of the solidified or cured treatment liquid on the substrate by the volatile component volatilizes A second liquid supply step for supplying,
Wherein the distortion caused by volume shrinkage of the synthetic resin, the particles attached to the pattern pattern when the first liquid treatment liquid film covering the pattern on the substrate is supplied in the supplying step is solidified or cured A substrate cleaning method, wherein the substrate is separated from the pattern while being covered with the treatment liquid film . A computer-readable storage medium that operates on a computer and stores a program for controlling the substrate cleaning apparatus,
15. A storage medium that, when executed, causes a computer to control the substrate cleaning apparatus so that the substrate cleaning method according to claim 14 is performed.

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