JP2015062259A - Substrate cleaning system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove particles adhering to a substrate while inhibiting pattern collapse and corrosion of a base film.SOLUTION: A substrate cleaning system according to one embodiment includes: a first processing part; and a second processing part. The first processing part includes: a first holding part which holds the substrate; and a first supply part for supplying a process liquid, which contains a volatile component and is used for forming a film on an entire main surface of the substrate, to the substrate. The second processing part includes: a second holding part which holds the substrate; and a second supply part for supplying a removal liquid, which melts the entire film formed by volatilizing the volatile component from the process liquid supplied to the substrate by the first supply part and solidifying or curing the processing liquid on the substrate, to the substrate, the second supply part for supplying a rinse liquid, which removes the melted film and the removal liquid remaining on the substrate from the substrate, to the substrate. The first processing part includes a process liquid recovery cup for recovering the process liquid.

Description

  The disclosed embodiments relate to a substrate cleaning system.

  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 using physical force generated by supplying a fluid such as liquid or gas to the main 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 main surface of the 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 main 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 system capable of removing particles attached to a substrate while suppressing pattern collapse and erosion of a base film.

  A substrate cleaning system according to an aspect of an embodiment includes a first processing unit and a second processing unit. The first processing unit includes a first holding unit that holds the substrate, and a first supply unit that supplies a processing liquid that contains a volatile component and forms a film over the entire main surface of the substrate to the substrate. The second processing unit includes a second holding unit that holds the substrate, and all films formed by solidifying or curing the substrate by volatilizing volatile components from the processing liquid supplied to the substrate by the first supply unit. And a second supply unit that supplies a rinsing liquid that removes the dissolved film remaining on the substrate and the removal liquid from the substrate to the substrate. The first processing unit includes a processing liquid recovery cup for recovering the processing liquid.

  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. In addition, since a different holding unit is used for supplying the processing liquid to the substrate and for supplying the removing liquid to the substrate, the processing liquid adheres to the second holding unit that holds the substrate when the removing liquid is supplied. Can be prevented.

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 illustrating the configuration of the first processing unit. FIG. 4 is a schematic diagram illustrating a configuration of the second processing unit. FIG. 5 is a flowchart showing the processing procedure of the substrate cleaning process executed by the substrate cleaning apparatus. FIG. 6A is an explanatory diagram of the operation of the first processing unit. FIG. 6B is an operation explanatory diagram of the first processing unit. FIG. 6C is an operation explanatory diagram of the first processing unit. FIG. 7A is an operation explanatory diagram of the second processing unit. FIG. 7B is an operation explanatory diagram of the second processing unit. FIG. 8A is an operation explanatory diagram of the second processing unit. FIG. 8B is an operation explanatory diagram of the second processing unit. FIG. 8C is an operation explanatory diagram of the second processing unit. FIG. 9 is a schematic diagram illustrating a configuration of a second processing unit according to the second embodiment. FIG. 10A is a schematic diagram illustrating a modification of the rotation holding mechanism included in the second processing unit. FIG. 10B is a schematic diagram illustrating a modification of the rotation holding mechanism included in the second processing unit. FIG. 11A is a diagram illustrating the wafer transfer timing. FIG. 11B is a diagram illustrating another example of the wafer transfer timing. FIG. 11C is a diagram illustrating another example of the wafer transfer timing. FIG. 12A is a diagram illustrating a modification in the case where a volatilization promoting function is provided in the first processing unit. FIG. 12B is a diagram illustrating a modification in the case where a volatilization promoting function is provided in the first processing unit. FIG. 13 is a schematic diagram illustrating a schematic configuration of a substrate cleaning system according to the fifth embodiment. FIG. 14 is a schematic diagram illustrating an example of the configuration of the third processing unit. FIG. 15A is an explanatory diagram of comparative conditions between this cleaning method and two-fluid cleaning. FIG. 15B is an explanatory diagram of comparison conditions between this cleaning method and two-fluid cleaning. FIG. 16 is a diagram showing a comparison result between this cleaning method and two-fluid cleaning. FIG. 17 is a diagram showing a comparison result between this cleaning method and chemical cleaning. FIG. 18 is a diagram showing a comparison result between this cleaning method and chemical cleaning.

  Hereinafter, embodiments of a substrate cleaning system 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 21 and a substrate delivery table 22 therein. In the transfer station 2, the substrate transfer device 21 delivers the wafer W between the carrier C placed on the carry-in / out station 1 and the substrate delivery table 22.

  The processing station 3 is disposed behind the transfer station 2. In the processing station 3, a substrate transfer device 31 is disposed at the center.

  A substrate cleaning device 7 is disposed in the processing station 3. The substrate cleaning apparatus 7 includes a first processing unit 5 and a second processing unit 6 constituting a processing unit different from the first processing unit 5.

  The first processing unit 5 and the second processing unit 6 are disposed on both the left and right sides of the substrate transfer apparatus 31, respectively. In the processing station 3, a total of six pairs of the first processing unit 5 and the second processing unit 6 are arranged in the front-rear direction. In addition, arrangement | positioning of the 1st process part 5 and the 2nd process part 6 is not limited to the thing of illustration.

  In the processing station 3, the substrate transfer device 31 transfers the wafers W one by one between the substrate delivery table 22, the first processing unit 5, and the second processing unit 6 of the transfer station 2, and The first processing unit 5 and the second processing unit 6 perform the substrate cleaning process on the wafer W one by one.

  The substrate cleaning system 100 includes a control device 8. The control device 8 is a device that controls the operation of the substrate cleaning system 100. The control device 8 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 recording medium and installed in the storage unit of the control device 8 from the recording medium. Examples of the computer-readable recording 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 8 is provided outside the substrate cleaning system 100 for convenience, but the control device 8 may be provided inside the substrate cleaning system 100. For example, the control device 8 can be accommodated in the upper space of the first processing unit 5 or the second processing unit 6.

  In the substrate cleaning system 100 configured as described above, first, the substrate transfer device 21 of the transfer station 2 takes out one wafer W from the carrier C placed on the carry-in / out station 1 and uses the taken wafer W as a substrate. Place on delivery table 22. The wafer W placed on the substrate delivery table 22 is loaded into the first processing unit 5 by the substrate transfer device 31 of the processing station 3 and then loaded into the second processing unit 6. Details of the substrate cleaning process performed in the first processing unit 5 and the second processing unit 6 will be described later.

  The wafer W cleaned by the first processing unit 5 and the second processing unit 6 is unloaded from the second processing unit 6 by the substrate transfer device 31 and placed on the substrate delivery table 22 again. Then, the processed wafer W placed on the substrate delivery table 22 is returned to the carrier C by the substrate transfer device 21.

  Here, in the conventional substrate cleaning apparatus, particle removal using physical force and particle removal using chemical action of chemicals are performed. However, in these methods, there is a possibility that the pattern formed on the main 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 7 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 7 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. In the following, the circuit formation surface of the wafer W is referred to as “main surface”, and the surface opposite to the main surface is referred to as “back surface”.

  As shown in FIG. 2A, in the first embodiment, a processing liquid containing a volatile component and forming a film on the entire main surface of the wafer W (hereinafter referred to as “film forming processing liquid”) is described as the processing liquid. ) Is used. Specifically, a film-forming treatment liquid (hereinafter referred to as “topcoat liquid”) for forming a topcoat film on the wafer W is used. Note that the top coat film is a protective film applied to the 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 7 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 is effective in that it gives a tensile force to the particles because it has a larger curing shrinkage than other resins such as an epoxy resin.

  Thereafter, the substrate cleaning device 7 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.

  In addition, although the example in the case of utilizing the volume shrinkage of the top coat liquid has been described here, in order to remove particles, it is sufficient that distortion (tensile force) is generated due to the volume change of the treatment liquid, and the volume shrinkage is limited. Not. That is, when the resin contained in the topcoat liquid has a property that the volume expands when it is solidified or cured, the volume expansion of the topcoat liquid occurs when the resin is solidified or cured, resulting in distortion (tensile force). Can remove particles.

  All of the film forming treatment liquid such as the top coat 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 7 will be specifically described. First, the configuration of the first processing unit 5 will be described with reference to FIG. FIG. 3 is a schematic diagram showing the configuration of the first processing unit 5. In FIG. 3, only components necessary for explaining the characteristics of the first processing unit 5 are shown, and descriptions of general components are omitted.

  As shown in FIG. 3, the first processing unit 5 includes a first substrate holding unit 52, liquid supply units 53, 54, and 55, and a collection cup 56 in the first chamber 51.

  The first substrate holding unit 52 includes a suction holding unit 521 that sucks and holds the wafer W, a support member 522 that supports the suction holding unit 521, and a drive unit 523 that rotates the support member 522.

  The suction holding unit 521 is connected to a suction device such as a vacuum pump, and holds the wafer W horizontally by sucking the back surface of the wafer W by using a negative pressure generated by suction of the suction device. For example, a porous chuck can be used as the suction holding unit 521.

  The support member 522 is provided below the suction holding unit 521 and is rotatably supported by the first chamber 51 and the recovery cup 56 via a bearing 524.

  The drive unit 523 is provided below the support member 522 and rotates the support member 522 around the vertical axis. As a result, the wafer W sucked and held by the suction holding unit 521 rotates.

  The liquid supply units 53 and 54 move from the outside of the wafer W to above the wafer W, and supply the processing liquid toward the main surface of the wafer W held by the first substrate holding unit 52. The liquid supply unit 53 includes nozzles 531, 534, 535, an arm 532 that horizontally supports the nozzles 531, 534, and 535, and a turning lift mechanism 533 that turns and lifts the arm 532. The liquid supply unit 54 includes nozzles 541 and 544, an arm 542 that horizontally supports the nozzles 541 and 544, and a turning lift mechanism 543 that turns and lifts the arm 542.

  The liquid supply unit 53 supplies a predetermined chemical liquid (here, DHF) to the wafer W from the nozzle 531, supplies DIW (pure water), which is a type of rinse liquid, from the nozzle 534, and supplies the dry solvent. One type of IPA (isopropyl alcohol) is supplied from the nozzle 535. DHF is dilute hydrofluoric acid.

  Specifically, a DHF supply source 111 is connected to the nozzle 531 via the valve 121, and DHF supplied from the DHF supply source 111 is supplied onto the wafer W from the nozzle 531. In addition, a DIW supply source 112 is connected to the nozzle 534 via a valve 122, and DIW supplied from the DIW supply source 112 is supplied onto the wafer W from the nozzle 534. Further, an IPA supply source 113 is connected to the nozzle 535 via a valve 123, and IPA supplied from the IPA supply source 113 is supplied onto the wafer W from the nozzle 535. Thus, the liquid supply unit 53 is an example of a chemical solution supply unit that supplies a predetermined chemical solution to the substrate and a pure water supply unit that supplies pure water to the substrate.

  The liquid supply unit 54 supplies a top coat liquid, which is a film forming process liquid, to the wafer W from the nozzle 541, and uses MIBC (4-methyl-2-pentanol) as a solvent having an affinity for the top coat liquid. Supply from nozzle 544. Specifically, a film forming processing liquid supply source 114 is connected to the nozzle 541 via a valve 124, and the top coat liquid supplied from the film forming processing liquid supply source 114 is supplied from the nozzle 541 onto the wafer W. To be supplied. Further, a solvent supply source 132 is connected to the nozzle 544 (corresponding to a “solvent supply unit”) via a valve 131, and MIBC supplied from the solvent supply source 132 is supplied onto the wafer W from the nozzle 544. .

  MIBC is a component contained in the topcoat liquid and has an affinity for the topcoat liquid. 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.

  Here, the dedicated nozzles 531, 534, 535, 541, and 544 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 532, and DHF, DIW, and IPA may be selectively supplied from the nozzle. Similarly, one nozzle may be provided on the arm 542, and the topcoat liquid and MIBC 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 531, 534, 535, 541, and 544 are provided, the process liquid is not required to be discharged as described above, so that the process liquid is not wasted.

  The liquid supply unit 55 is provided, for example, at the bottom of the recovery cup 56 and supplies an alkali developer to the peripheral portion on the back side of the wafer W. Specifically, a removal liquid supply source 115 is connected to the liquid supply unit 55 via a valve 125, and an alkaline developer supplied from the removal liquid supply source 115 is supplied to the peripheral portion on the back surface side of the wafer W. To do. The liquid supply unit 55 is used for removing the top coat liquid or the top coat film adhering to the bevel part and the peripheral part of the wafer W. This point will be described later.

  The recovery cup 56 is disposed so as to surround the first substrate holding part 52 in order to prevent the processing liquid from scattering to the periphery. A drain port 561 is formed at the bottom of the recovery cup 56, and the processing liquid collected by the recovery cup 56 is discharged from the drain port 561 to the outside of the first processing unit 5.

  Next, the configuration of the second processing unit 6 will be described with reference to FIG. FIG. 4 is a schematic diagram showing the configuration of the second processing unit 6.

  As shown in FIG. 4, the second processing unit 6 includes a second substrate holding unit 62, a liquid supply unit 63, a recovery cup 64, and an airflow forming unit 65 in the second chamber 61.

  The second substrate holding unit 62 includes a rotation holding mechanism 621 that rotatably holds the wafer W, and a fluid supply unit 622 that is inserted into the hollow portion 621d of the rotation holding mechanism 621 and supplies gas to the back surface of the wafer W. Prepare.

  The rotation holding mechanism 621 is provided substantially at the center of the second chamber 61. A grip portion 621 a that grips the peripheral edge of the wafer W is provided on the upper surface of the rotation holding mechanism 621, and the wafer W is horizontally separated from the upper surface of the rotation holding mechanism 621 by the grip portion 621 a. Retained.

  The rotation holding mechanism 621 includes a driving mechanism 621b, and rotates around the vertical axis by the driving mechanism 621b. Specifically, the drive mechanism 621b includes a motor 621b1, a pulley 621b2 attached to the output shaft of the motor 621b1, and a belt 621b3 wound around the outer periphery of the pulley 621b2 and the rotation holding mechanism 621.

  The drive mechanism 621b rotates the pulley 621b2 by the rotation of the motor 621b1, and transmits the rotation of the pulley 621b2 to the rotation holding mechanism 621 by the belt 621b3, thereby rotating the rotation holding mechanism 621 around the vertical axis. Then, when the rotation holding mechanism 621 rotates, the wafer W held by the rotation holding mechanism 621 rotates integrally with the rotation holding mechanism 621. The rotation holding mechanism 621 is rotatably supported by the second chamber 61 and the recovery cup 64 via a bearing 621c.

  The fluid supply part 622 is a long member inserted through a hollow part 621 d formed at the center of the rotation holding mechanism 621. A flow path 622 a is formed inside the fluid supply unit 622. The N2 supply source 118 and the SC1 supply source 119 are connected to the flow path 622a through the valve 128 and the valve 129, respectively. The fluid supply unit 622 supplies the N2 gas and SC1 (ammonia hydrogen peroxide) supplied from the N2 supply source 118 and the SC1 supply source 119 to the back surface of the wafer W through the flow path 622a.

  Here, the N 2 gas supplied through the valve 128 is a high-temperature (for example, about 90 ° C.) N 2 gas, and is used in a volatilization promoting process described later.

  The fluid supply unit 622 is also used when transferring the wafer W. Specifically, an elevating mechanism 622b that moves the fluid supply unit 622 in the vertical direction is provided at the base end of the fluid supply unit 622. In addition, support pins 622 c for supporting the wafer W are provided on the upper surface of the fluid supply unit 622.

  When receiving the wafer W from the substrate transfer device 31 (see FIG. 1), the second substrate holding unit 62 raises the fluid supply unit 622 using the lifting mechanism 622b and places the wafer on the support pins 622c. W is placed. Thereafter, the second substrate holding unit 62 lowers the fluid supply unit 622 to a predetermined position, and then transfers the wafer W to the gripping unit 621a of the rotation holding mechanism 621. Further, when the processed wafer W is transferred to the substrate transfer apparatus 31, the second substrate holding unit 62 raises the fluid supply unit 622 using the lifting mechanism 622b, and the wafer W held by the holding unit 621a is moved up. It mounts on the support pin 622c. Then, the second substrate holding unit 62 passes the wafer W placed on the support pins 622c to the substrate transfer apparatus 31.

  The liquid supply unit 63 moves from the outside of the wafer W to above the wafer W, and supplies the processing liquid toward the main surface of the wafer W held by the second substrate holding unit 62. The liquid supply unit 63 includes nozzles 631 and 635, an arm 632 that horizontally supports the nozzles 631 and 635, and a turning lift mechanism 633 that turns and lifts the arm 632.

  The liquid supply unit 63 supplies an alkaline developer, which is a removal liquid, to the wafer W from the nozzle 631 and supplies DIW, which is a type of rinse liquid, from the nozzle 635. Specifically, a removal liquid supply source 116 is connected to the nozzle 631 via a valve 126, and an alkaline developer supplied from the removal liquid supply source 116 is supplied onto the wafer W from the nozzle 631. Further, a DIW supply source 117 is connected to the nozzle 635 via a valve 127, and DIW supplied from the DIW supply source 117 is supplied onto the wafer W.

  The recovery cup 64 is disposed so as to surround the rotation holding mechanism 621 in order to prevent the processing liquid from being scattered around. A drain port 641 is formed at the bottom of the recovery cup 64, and the processing liquid collected by the recovery cup 64 is discharged from the drain port 641 to the outside of the second processing unit 6. Further, an exhaust port 642 is formed at the bottom of the recovery cup 64, and N2 gas supplied by the fluid supply unit 622 or gas supplied into the second processing unit 6 from the airflow forming unit 65 to be described later, The air is discharged from the exhaust port 642 to the outside of the second processing unit 6.

  An exhaust port 611 is formed at the bottom of the second chamber 61, and a pressure reducing device 66 is connected to the exhaust port 611. The decompression device 66 is a vacuum pump, for example, and makes the inside of the second chamber 61 decompressed by intake air.

  The airflow forming unit 65 is attached to the ceiling portion of the second chamber 61 and is an airflow generating unit that forms a downflow in the second chamber 61. Specifically, the airflow forming unit 65 includes a downflow gas supply pipe 651 and a buffer chamber 652 communicating with the downflow gas supply pipe 651. The downflow gas supply pipe 651 is connected to a downflow gas supply source (not shown). In addition, a plurality of communication ports 652 a that communicate the buffer chamber 652 and the second chamber 61 are formed at the bottom of the buffer chamber 652.

  The airflow forming unit 65 supplies downflow gas (for example, clean gas or dry air) to the buffer chamber 652 via the downflow gas supply pipe 651. Then, the airflow forming unit 65 supplies the downflow gas supplied to the buffer chamber 652 into the second chamber 61 through the plurality of communication ports 652a. As a result, a downflow is formed in the second chamber 61. The downflow formed in the second chamber 61 is discharged from the exhaust port 642 and the exhaust port 611 to the outside of the second processing unit 6.

  Next, a specific operation of the substrate cleaning apparatus 7 will be described. FIG. 5 is a flowchart showing the processing procedure of the substrate cleaning process executed by the substrate cleaning apparatus 7. 6A to 6C are operation explanatory diagrams of the first processing unit 5, and FIGS. 7A, 7B, and 8A to 8C are operation explanatory diagrams of the second processing unit 6. FIG. More specifically, FIGS. 6A to 6C show an operation example of the processing liquid supply process for film formation (step S106) in FIG. 5, and FIG. 7A shows an operation example of the volatilization promotion process (step S109) in FIG. FIG. 7B shows an operation example of the back surface cleaning process (step S110) in FIG.

  8A shows an operation example of the removal liquid supply process (step S111) in FIG. 5, FIG. 8B shows an operation example of the rinse process (step S112) in FIG. 5, and FIG. 8C shows an operation example in FIG. The example of operation | movement of a drying process (step S113) is shown. Each processing procedure shown in FIG. 5 is performed based on the control of the control device 8.

  In the substrate cleaning apparatus 7 according to the first embodiment, the first processing unit 5 performs the processes from the first carry-in process (step S101) to the first carry-out process (step S107), and the second process unit 6 performs the first process. Processes from the 2 carry-in process (step S108) to the second carry-out process (step S114) are performed.

  As shown in FIG. 5, in the 1st process part 5, a 1st carrying-in process is first performed (step S101). In the first carry-in process, after the collection cup 56 is lowered and the substrate transfer device 31 places the wafer W on the suction holding unit 521, the wafer holding unit 521 sucks and holds the wafer W. At this time, the wafer W is held by the suction holding unit 521 with the circuit formation surface facing upward. Thereafter, the first substrate holding unit 52 is rotated by the driving unit 523. As a result, the wafer W rotates together with the first substrate holding unit 52 while being horizontally held by the first substrate holding unit 52.

  Subsequently, in the first processing unit 5, chemical solution processing is performed (step S102). In such chemical processing, the nozzle 531 of the liquid supply unit 53 is positioned above the center of the wafer W. Thereafter, DHF as a cleaning liquid is supplied from the nozzle 531 to the main surface of the wafer W. The DHF supplied to the main surface of the wafer W spreads on the main surface of the wafer W due to the centrifugal force accompanying the rotation of the wafer W. Thereby, the unnecessary film | membrane of the whole main surface of the wafer W is melt | dissolved by DHF. That is, since the surface of the base film on the main surface of the wafer W and the surface of the particles are dissolved by DHF, the adhesion force of the particles is weakened, so that the particles can be easily removed.

  The chemical solution (DHF in this case) used for the chemical treatment in step S102 is used under conditions where the etching amount is small as compared with a chemical solution in a 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.

  In this way, by performing the chemical liquid processing in step S102, it is possible to remove particles more effectively than in the case where the chemical liquid processing in step S102 is not performed. It should be noted that the chemical treatment in step S102 is not necessarily performed.

  The chemical solution used for the chemical treatment in step S102 is not limited to DHF as long as it is a 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 such a chemical solution include ammonium fluoride, hydrochloric acid, sulfuric acid, hydrogen peroxide solution, phosphoric acid, acetic acid, nitric acid, ammonium hydroxide and the like in addition to DHF.

  Subsequently, in the first processing unit 5, the main surface of the wafer W is rinsed with DIW to perform rinsing processing (step S103). In the rinsing process, the nozzle 534 is positioned above the center of the wafer W. Thereafter, the valve 122 (see FIG. 3) is opened for a predetermined time, whereby DIW is supplied from the nozzle 534 of the liquid supply unit 53 to the main surface of the rotating wafer W, and DHF remaining on the wafer W is washed away.

  Subsequently, in the first processing unit 5, a replacement process is performed (step S104). In such replacement processing, the nozzle 535 is positioned above the center of the wafer W. Thereafter, when the valve 123 (see FIG. 3) is opened for a predetermined time, IPA is supplied from the nozzle 535 of the liquid supply unit 53 to the main surface of the rotating wafer W, and DIW on the wafer W is replaced with IPA. . Thereafter, the rotation of the wafer W stops with the IPA remaining on the wafer W. When the replacement process is completed, the nozzle 535 moves to the outside of the wafer W.

  Subsequently, in the first processing unit 5, a solvent supply process is performed (step S105). 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 544 of the liquid supply unit 54 is positioned above the center of the wafer W, and thereafter, the MIBC is supplied from the nozzle 544 to the main surface of the wafer W. The MIBC supplied to the main surface of the wafer W is spread on the main 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 is likely to spread on the main surface of the wafer W in the film forming process liquid supply process described later. At the same time, it is easy to enter the gaps between the patterns. Therefore, it is possible to reduce the consumption of the topcoat liquid and more reliably remove particles that have entered the pattern gap.

  MIBC has an affinity with the topcoat solution, but is hardly mixed with DIW and has a low affinity. On the other hand, the first processing unit 5 replaces DIW with IPA having higher affinity with MIBC than DIW before supplying MIBC. Thereby, compared with the case where the solvent supply process (step S105) is performed immediately after the rinsing process (step S103), the MIBC can easily spread on the main surface of the wafer W, and the consumption of MIBC can be suppressed.

  Note that when the solvent having affinity for the film-forming treatment liquid has affinity for not only the film-forming treatment liquid but also DIW, the replacement process in step S104 may be omitted.

  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 drainage port 561 of the recovery cup 56 (see FIG. 3) is connected to the recovery line via the switching valve 15 (not shown). Thereby, the MIBC scattered from the wafer W by the centrifugal force is discharged from the drain port 561 of the recovery cup 56 to the recovery line via the switching valve.

  Subsequently, in the first processing unit 5, a film forming process liquid supply process is performed (step S106). In the film forming process liquid supply process, the nozzle 541 of the liquid supply unit 54 is positioned above the center of the wafer W. Thereafter, as shown in FIG. 6A, a topcoat liquid that is a film-forming treatment liquid is supplied from a nozzle 531 to the main surface of the wafer W that is a circuit formation surface on which no resist film is formed.

  The top coat liquid supplied to the main surface of the wafer W spreads on the main surface of the wafer W due to the centrifugal force accompanying the rotation of the wafer W. As a result, a topcoat liquid film is formed on the entire main surface of the wafer W as shown in FIG. 6B. At this time, the main surface of the wafer W is in a state in which the wettability is enhanced by the MIBC supplied onto the wafer W in step S105. As a result, the topcoat liquid is likely to spread on the main surface of the wafer W and also easily enters the gaps 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.

  Then, as the volatile component is volatilized by the rotation of the wafer W, the topcoat liquid is solidified. Thereby, a top coat film is formed on the entire main surface of the wafer W. When the film forming process liquid supply process is completed, the nozzle 531 moves to the outside of the wafer W.

  By the way, the top coat liquid supplied to the main surface of the wafer W slightly wraps around from the peripheral portion of the wafer W to the back surface of the wafer W as shown in FIG. 6B. For this reason, the top coat film is also formed on the bevel portion of the wafer W and the peripheral portion on the back surface side.

  Therefore, in the first processing unit 5, after supplying the topcoat liquid from the nozzle 531 to the main surface of the wafer W, the first processing unit 5 removes the liquid supply unit 55 from the peripheral portion on the back surface side of the wafer W as shown in FIG. 6C. A liquid (here, an alkaline developer) is supplied. The alkali developer is supplied to the peripheral portion on the back surface side of the wafer W, and then flows from the bevel portion of the wafer W to the peripheral portion on the main surface side. Thereby, the top coat film or the top coat liquid adhering to the peripheral portion on the back surface side, the bevel portion and the peripheral portion on the main surface side of the wafer W is removed. Thereafter, the rotation of the wafer W is stopped.

  Subsequently, in the first processing unit 5, a first carry-out process is performed (step S107). In the first carry-out process, the recovery cup 56 is lowered and the wafer W held by the first substrate holding unit 52 is transferred to the substrate transfer device 31. The wafer W is unloaded from the first processing unit 5 in a state where the topcoat liquid is solidified on the circuit formation surface and a topcoat film is formed.

  Subsequently, in the second processing unit 6, a second carry-in process is performed (step S108). In the second carry-in process, after the substrate transport device 31 places the wafer W on the support pins 622c of the fluid supply unit 622, the grip unit 621a of the rotation holding mechanism 621 grips the wafer W. At this time, the wafer W is held by the holding unit 621a with the circuit forming surface facing upward. Thereafter, the rotation holding mechanism 621 is rotated by the drive mechanism 621b. As a result, the wafer W rotates together with the rotation holding mechanism 621 while being held horizontally by the rotation holding mechanism 621.

  Subsequently, in the second processing unit 6, a volatilization promotion process is performed (step S109). Such a volatilization promoting process is a process for promoting further volatilization of a volatile component contained in the top coat liquid that forms a film on the entire main surface of the wafer W. Specifically, as shown in FIG. 7A, when the valve 128 (see FIG. 4) is opened for a predetermined time, high-temperature N 2 gas is supplied from the fluid supply unit 622 to the back 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.

  In addition, the pressure inside the second chamber 61 is reduced by the pressure reducing device 66 (see FIG. 4). Also by this, volatilization of the volatile component can be promoted. Further, downflow gas is supplied from the airflow forming unit 65 during the substrate cleaning process. The volatilization of the volatile components can also be promoted by reducing the humidity in the airflow forming unit 65 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, in the substrate cleaning apparatus 7, by promoting the volatilization of the volatile components contained in the film-forming treatment liquid, it is possible to shorten the time until the film-forming treatment liquid is solidified or cured. 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 fluid supply unit 622, the decompression device 66, and the airflow forming unit 65 are examples of “a volatilization promoting unit”. Here, the second processing unit 6 includes the fluid supply unit 622, the decompression device 66, and the airflow forming unit 65 as the volatilization promoting unit. However, the second processing unit 6 includes any one of these. It may be.

  Moreover, although the example in which the 2nd process part 6 performs a volatilization promotion process was shown here, a volatilization promotion process is omissible. That is, the second processing unit 6 may be kept on standby until the top coat liquid is naturally solidified or cured. Further, volatilization of the top coat liquid is stopped by stopping the rotation of the wafer W or rotating the wafer W at a rotation speed that does not expose the main surface of the wafer W by shaking the top coat liquid. It may be promoted.

  Subsequently, in the second processing unit 6, a back surface cleaning process is performed (step S110). In such a back surface cleaning process, the valve 129 (see FIG. 4) is opened for a predetermined time, whereby SC1 is supplied from the fluid supply unit 622 to the back surface of the rotating wafer W (see FIG. 7B). Thereby, the back surface of the wafer W is cleaned. SC1 supplied to the back surface of the wafer W is discharged from a drain port 641 of the recovery cup 64 to a waste liquid line via a switching valve (not shown). The fluid supply unit 622 is also an example of a back surface cleaning unit that supplies a cleaning liquid to the center of the back surface of the wafer W held by the holding unit 621a.

  As described above, in the substrate cleaning apparatus 7 according to the first embodiment, the film forming processing liquid supply process is performed in the first processing unit 5 including the suction holding unit 521 that sucks and holds the back surface of the wafer W. Therefore, for example, compared to the case where a substrate holding part of the type that holds the peripheral edge of the wafer W is used like the second substrate holding part 62 provided in the second processing part 6, the topcoat liquid is applied to the peripheral part of the wafer W. No application leakage occurs. Further, since the topcoat liquid does not adhere to the substrate holding part, there is no possibility that the wafer W is soiled by gripping the wafer W by the substrate holding part to which the topcoat liquid has adhered.

  In the substrate cleaning apparatus 7 according to the first embodiment, the back surface cleaning process is performed in the second processing unit 6 including the rotation holding mechanism 621 that holds the peripheral edge of the wafer W. Therefore, it is possible to remove dirt on the back surface of the wafer W, particularly dirt caused by the suction holding unit 521 of the first processing unit 5.

  In the substrate cleaning apparatus 7 according to the first embodiment, the back surface of the wafer W is cleaned while the main surface of the wafer W is covered with the solidified or hardened top coat liquid. For this reason, even if the cleaning liquid is scattered during the back surface cleaning process, it is possible to prevent the cleaning liquid from adhering to the main surface of the wafer W and contaminating the main surface of the wafer W. In addition, contamination of the main surface of the wafer W due to the wraparound of the cleaning liquid can be prevented.

  In addition, although the example in the case of performing a back surface cleaning process after a volatilization acceleration process was shown here, you may perform a back surface cleaning process after a 2nd carrying-in process and before a volatilization acceleration process.

  Subsequently, in the second processing unit 6, a removal liquid supply process is performed (step S111). In the removal liquid supply process, the nozzle 631 is positioned above the center of the wafer W as shown in FIG. 8A. Thereafter, the valve 126 (see FIG. 4) is opened for a predetermined time, whereby an alkaline developer as a removing solution is supplied onto the rotating wafer W from the nozzle 631. 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.

  The removal liquid splashed from the wafer W due to the centrifugal force is discharged from the drain port 641 of the recovery cup 64 to the recovery line via a switching valve (not shown). The removal liquid discharged to the recovery line is reused.

  It should be noted that the drain port 641 is connected to the waste liquid line for a predetermined time from the start of the supply of the removing liquid until the topcoat film is sufficiently removed, and then the drain port 641 is connected to the recovery line. You may do it. Thereby, it can prevent that a topcoat film | membrane mixes in the removal liquid to recycle.

  Subsequently, in the second processing unit 6, the main surface of the wafer W is rinsed with DIW (Step S112). In the rinsing process, the nozzle 635 is positioned above the center of the wafer W as shown in FIG. 8B. Thereafter, the valve 127 (see FIG. 4) is opened for a predetermined time, whereby DIW is supplied from the nozzle 635 of the liquid supply unit 63 to the main surface of the rotating wafer W, and the top coat film and alkali remaining on the wafer W are supplied. The developer is washed away.

  Specifically, DIW supplied onto the wafer W is scattered outside the wafer W while being diffused onto 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 DIW. At this time, the inside of the second chamber 61 can be quickly exhausted by the downflow formed by the airflow forming unit 65. When the rinsing process is completed, the nozzle 635 moves to the outside of the wafer W.

  Subsequently, in the second processing unit 6, a drying process is performed (step S113). In this drying process, the DIW remaining on the main 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. 8C). Thereafter, the rotation of the wafer W is stopped.

  And in the 2nd process part 6, a 2nd carrying-out process is performed (step S114). In such substrate carry-out processing, the fluid supply unit 622 is raised by the lifting mechanism 622b (see FIG. 4), and the wafer W held by the gripping unit 621a is placed on the support pins 622c. Then, the wafer W placed on the support pins 622c is transferred to the substrate transfer device 31. 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 second processing unit 6 with the circuit forming surface exposed.

  As described above, the substrate cleaning system 100 according to the first embodiment includes the first processing unit 5 and the second processing unit 6. The first processing unit 5 includes a first substrate holding unit 52 (an example of a first holding unit) that holds the wafer W and a processing liquid that contains a volatile component and forms a film on the entire main surface of the substrate. Liquid supply unit 54 (an example of a first supply unit) to be supplied. The second processing unit 6 constitutes a processing unit different from the first processing unit 5, and is supplied to the substrate by the second substrate holding unit 62 (an example of the second holding unit) that holds the wafer W and the liquid supply unit 53. A liquid supply unit 63 (an example of a second supply unit) that supplies to the wafer W a removal liquid that dissolves all of the film formed by solidifying or curing on the substrate by volatilization of volatile components from the treated liquid. Including.

  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.

  Further, in the substrate cleaning system 100 according to the first embodiment, different substrate holders are used for the film forming process liquid supply process and the removal liquid supply process. Specifically, since the film forming process liquid supply process is performed in the first processing unit 5 including the suction holding unit 521 that sucks and holds the back surface of the wafer W, the topcoat liquid is applied to the peripheral portion of the wafer W. Application leakage and adhesion of the top coat liquid to the substrate holding part can be prevented. Further, since the removal liquid supply process is performed in the second processing unit 6 including the rotation holding mechanism 621 that holds the peripheral edge of the wafer W, the back surface of the wafer W can be cleaned before the removal liquid supply process. The dirt by the suction holding unit 521 of the first processing unit 5 can be removed. Moreover, it can prevent that a topcoat liquid adheres to a 2nd holding | maintenance part.

  Further, the substrate cleaning system 100 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, the comparison conditions will be described with reference to FIGS. 15A and 15B. FIG. 15A and FIG. 15B are explanatory diagrams of comparative conditions between this cleaning method and two-fluid cleaning.

  As shown in FIGS. 15A and 15B, a wafer without a pattern (see FIG. 15A) 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. 15B). ) 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. 16 is a diagram showing a comparison result between this cleaning method and two-fluid cleaning. In FIG. 16, the particle removal rate for the wafer without 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. 16, 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 wafer without pattern 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. 17 and 18 are diagrams showing comparison results between this cleaning method and chemical cleaning. FIG. 17 shows the comparison result of the particle removal rate, and FIG. 18 shows the comparison result of the 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. 15B was used as the wafer.

  As shown in FIG. 17, the particle removal rate by chemical cleaning is 97.5%, which is slightly lower than the particle removal rate (98.9%) of the present 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. 18, as a result of the chemical cleaning, a film loss of 7A (angstrom) was generated, but no film loss was generated 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 the first embodiment described above, an example in which the first holding unit included in the first processing unit 5 is a vacuum chuck that holds the wafer W by suction is shown. However, the first holding unit included in the first processing unit 5 is described. The part is not limited to a vacuum chuck. For example, the first holding unit may be a mechanical chuck that grips the peripheral edge of the wafer W, like the second substrate holding part 62 included in the second processing unit 6, or the peripheral part on the back surface side of the wafer W may be used. It may be a holding unit that supports (that is, only mounts the wafer W).

  In the first embodiment described above, after the chemical treatment (step S102 in FIG. 5), a rinsing process, a replacement process, and a solvent supply process (steps S103 to S105 in FIG. 5) are performed to form a film-forming treatment liquid supply process. (Step S106 in FIG. 5) is performed. However, the first processing unit 5 may perform the film-forming process liquid supply process after the chemical process without performing the rinse process, the replacement process, and the solvent supply process.

  In the first embodiment, the example in which the process of supplying SC1 to the back surface of the wafer W is performed as the back surface cleaning process has been described. However, the back surface cleaning process is not limited to the above process. . For example, brush cleaning using a brush, two-fluid cleaning using a two-fluid nozzle that mists the cleaning liquid with gas and sprays it on the back surface of the wafer W, or ultrasonic cleaning using an ultrasonic vibrator, etc. You may do as.

  In the first embodiment, the example in which the back surface cleaning process is performed in a state where the main surface of the wafer W is covered with the top coat film has been described. However, the process performed in such a state is not limited to the back surface cleaning process, for example, a polishing process for polishing the back surface or bevel portion of the wafer W using a polishing brush, a back surface of the wafer W using a chemical solution, An etching process or the like for etching the bevel portion may be used. The etching process is a process of removing the oxide film using, for example, hydrofluoric acid (HF).

  In this way, by processing the other surface of the wafer W in a state where the entire main surface of the wafer W is covered with the top coat film, the contamination of the main surface of the wafer W is prevented, while the other surface of the wafer W is protected. The surface can be processed. Further, by performing the etching process in a state where the main surface of the wafer W is covered with the top coat film, the main surface of the wafer W is covered with the top coat even if the chemical solution circulates from the back surface side to the main surface side. It is not etched because it is protected by the film. Thus, since the etching region is determined by the top coat film, the etching can be performed with high accuracy.

(Second Embodiment)
The configuration of the substrate cleaning apparatus is not limited to the configuration shown in the first embodiment. Therefore, hereinafter, another configuration of the substrate cleaning apparatus will be described with reference to FIG. FIG. 9 is a schematic diagram illustrating the 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.

  As shown in FIG. 9, the second processing unit according to the second embodiment is replaced with a liquid supply unit 63 provided in the second processing unit 6 (see FIG. 4) according to the first embodiment. 63A.

  The liquid supply unit 63A further includes a nozzle 634 in addition to the nozzles 631 and 635. The nozzle 634 is supported obliquely with respect to the arm 632, and is configured such that the discharge port faces the peripheral direction of the wafer W when the nozzle 631 is located above the center of the wafer W. The nozzle 634 is an example of a third supply unit.

  The removal liquid supply source 116 (see FIG. 4) is connected to the nozzle 634 via a valve (not shown). Then, the nozzle 634 discharges the alkaline developer supplied from the removal liquid supply source 116 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 grip portion 621a is supplied to the grip portion 621a.

  Note that the valve connected to the nozzle 634 is a different valve from the valve 126 (see FIG. 4) connected to the nozzle 631. Accordingly, the supply start timing and supply stop timing of the alkaline developer can be individually controlled by the nozzle 631 and the nozzle 634. Since the other configuration is the same as that of the second processing unit 6 according to the first embodiment, description thereof is omitted here.

  The second processing unit according to the second embodiment performs the cleaning process of the gripping unit 621a using the liquid supply unit 63A according to the control by the control device 8. Specifically, in the above-described removal liquid supply process (step S111 in FIG. 5), a valve and a valve 126 (not shown) connected to the nozzle 634 after the nozzle 631 is positioned above the center of the wafer W (see FIG. 4). Are released for a predetermined time, so that an alkaline developer as a removing solution is supplied from the nozzle 631 onto the rotating wafer W and supplied from the nozzle 634 to the periphery of the wafer W.

  Thereby, the topcoat film adhering to the grip portion 621a is dissolved and removed from the grip portion 621a. That is, the grip part 621a is cleaned.

  The valve connected to the nozzle 634 is closed before the valve 126 (see FIG. 4). As a result, the supply of the alkaline developer from the nozzle 634 to the grip portion 621a stops before the supply of the alkaline developer from the nozzle 631 to the wafer W.

  As a result, even if the top coat film adhering to the grip portion 621a is removed by the alkali developer supplied from the nozzle 634 and scattered to the wafer W side, it adheres to the wafer W by the alkali developer supplied from the nozzle 631. And can be washed away.

  As described above, according to the substrate cleaning apparatus according to the second embodiment, since the nozzle 634 that supplies the alkaline developer to the grip portion 621a is further provided, the top coat film attached to the grip portion 621a is removed. It is possible to prevent the wafer W from being soiled or dusting.

  Here, an example in which the supply of the alkaline developer from the nozzle 634 to the gripper 621a is stopped before the supply of the alkaline developer from the nozzle 631 to the wafer W is stopped is shown. The stop timing is not limited to this. For example, the supply of the alkaline developer from the nozzle 634 to the gripper 621a may be stopped before the rinsing process is completed, that is, before the supply of DIW from the nozzle 631 to the wafer W is stopped. Even in such a case, the top coat film removed from the gripping portion 621a can be washed away by DIW supplied from the nozzle 631, and adhesion to the wafer W can be prevented.

  As described above, the supply of the alkaline developer from the nozzle 634 to the gripper 621a may be stopped before the supply of the processing solution (alkaline developer or DIW) from the nozzle 631 to the wafer W is stopped.

(Third embodiment)
Next, a substrate cleaning apparatus according to the third embodiment will be described. FIG. 10A and FIG. 10B are schematic views showing a modification of the rotation holding mechanism provided in the second processing unit.

  As shown in FIG. 10A, the second processing unit according to the third embodiment is replaced with a rotation holding mechanism 621 provided in the second processing unit 6 (see FIG. 4) according to the first embodiment. 621 ′. Since the other configuration is the same as that of the second processing unit 6, the description thereof is omitted here.

  The rotation holding mechanism 621 ′ replaces the holding unit 621 a included in the rotation holding mechanism 621, and includes a first holding unit 621 e that holds the wafer W and a second holding unit that can operate independently of the first holding unit 621 e. Part 621f.

  A plurality of first holding portions 621e are provided at equal intervals along the circumferential direction of the wafer W, and here, three are provided at intervals of 120 degrees, and are configured to be movable along the radial direction of the wafer W. . The second grips 621f are arranged at equal intervals between the first grips 621e, and are configured to be movable along the radial direction of the wafer W, similarly to the first grips 621e.

  Thus, the 2nd processing part concerning a 3rd embodiment is provided with two grasping parts which can operate independently, and can change wafer W using these.

  For example, FIG. 10A shows a state where the wafer W is held by the first gripping portion 621e. In such a state, after the second grip 621f is moved in the direction approaching the wafer W, the first grip 621e is moved away from the wafer W, whereby the wafer W is moved as shown in FIG. 10B. The first gripper 621e can be changed to the second gripper 621f.

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

  As shown in FIG. 11A, the wafer W is changed between the first holding unit 621e and the second holding unit 621f at a predetermined timing during the removal liquid supply process (step S110 in FIG. 5). Specifically, after the start of the removal liquid supply process, the second gripping portion is washed away at a timing when the topcoat film is washed away to some extent by the alkaline developer and the topcoat film is not likely to adhere to the second gripping portion 621f. 621f is moved in a direction approaching the wafer W, and then the first gripping part 621e is moved in a direction away from the wafer W.

  As described above, in the third embodiment, the wafer W is changed between the first holding part 621e and the second holding part 621f. For this reason, even if the top coat film is attached to the first gripping part 621e, the wafer W can be prevented from being soiled or dusted by switching to the second gripping part 621f. it can.

  Note that the change from the first gripping part 621e to the second gripping part 621f may be performed immediately after the end of the back surface cleaning process, as shown in FIG. 11B, or as shown in FIG. 11C. It may be performed immediately after the end of. Since the top coat liquid is difficult to adhere to the second gripping part 621f by solidifying, the wafer W can be prevented from being soiled or dusted even if it is performed immediately after the completion of the volatilization promoting process.

  Moreover, the 2nd process part which concerns on 3rd Embodiment may be provided with the nozzle which supplies alkali removal liquid to the 1st holding part 621e like the 2nd process part which concerns on 2nd Embodiment. The first gripper 621e may be periodically cleaned using such a nozzle. Note that the cleaning process is preferably performed in a state where the wafer W is not present in the second chamber 61.

(Fourth embodiment)
In each of the above-described embodiments, an example has been described in which the deposition processing liquid supply process is performed in the first processing unit, and the volatilization promotion process and the removal liquid supply process are performed in the second processing unit. However, the volatilization promotion process may be performed in the first processing unit. Therefore, in the following, a modified example in which the volatilization promoting function is provided in the first processing unit will be described with reference to FIGS. 12A and 12B. FIG. 12A and FIG. 12B are diagrams showing a modification in the case where a volatilization promoting function is provided in the first processing unit.

  As illustrated in FIG. 12A, for example, the first processing unit includes a first substrate holding unit 52A instead of the first substrate holding unit 52. The adsorption holding unit 521A included in the first substrate holding unit 52A is provided with a heating unit 521A1, and volatilization promotion processing is performed by the heating unit 521A1. That is, the topcoat liquid is heated by the heating unit 521A1. 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, by providing the heating unit 521A1 in the suction holding unit 521A, the wafer W held by suction can be directly heated, so that the volatilization of the volatile components contained in the topcoat liquid is more effectively promoted. be able to. The heating unit 521A1 is an example of a volatilization promoting unit.

  Further, as shown in FIG. 12B, the first processing unit may further include an ultraviolet irradiation unit 57 as a volatilization promoting unit. The ultraviolet irradiation unit 57 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 main surface of the wafer W. Thereby, the topcoat liquid is activated and the volatilization of the volatile components is promoted.

  In addition, it is preferable to arrange | position the ultraviolet irradiation part 57 in the position higher than the nozzles 531 and 541 of the liquid supply parts 53 and 54 so that the process by the liquid supply parts 53 and 54 may not be inhibited. Alternatively, the ultraviolet irradiation unit 57 may be configured to be movable so as to be positioned above the wafer W only when the volatilization promotion process is performed.

  Moreover, the 1st process part may be provided with an airflow formation unit and a decompression device as a volatilization promotion part similarly to the 2nd process part 6. FIG. In addition, the first processing unit may include a nozzle that supplies high-temperature N 2 gas to the main surface of the wafer W from above the wafer W, and a heating unit such as a heater may be disposed above the wafer W. .

(Fifth embodiment)
In each of the embodiments described above, the volatilization promoting process is performed in either the first processing unit or the second processing unit. However, the substrate cleaning apparatus may further include a processing unit for the volatilization promoting process. Good. An example of such a case will be described with reference to FIG. FIG. 13 is a schematic diagram illustrating a schematic configuration of a substrate cleaning system according to the fifth embodiment.

  As shown in FIG. 13, the substrate cleaning system 100 ′ according to the fifth embodiment includes a processing station 3 ′ instead of the processing station 3 (see FIG. 1). Then, instead of the substrate cleaning device 7, a substrate cleaning device 7 ′ is disposed in the processing station 3 ′. Other configurations are the same as those of the substrate cleaning system 100.

  The substrate cleaning apparatus 7 ′ includes three processing units, a first processing unit 5 ′, a second processing unit 6 ′, and a third processing unit 9. The first processing unit 5 ′, the second processing unit 6 ′, and the third processing unit 9 are arranged in the order of the first processing unit 5 ′, the third processing unit 9, and the second processing unit 6 ′. Are arranged side by side in the front-rear direction. However, the arrangement of the first processing unit 5 ′, the second processing unit 6 ′, and the third processing unit 9 is not limited to the illustrated one.

  The first processing unit 5 ′ has the same configuration as the first processing unit 5 according to the first embodiment, for example. Further, the second processing unit 6 ′ excludes the configuration (N2 supply source 118, valve 128, airflow forming unit 65, decompression device 66, etc.) related to the volatilization promotion processing from the second processing unit 6 according to the first embodiment, for example. The configuration is as follows.

  The third processing unit 9 is a processing unit for volatilization promotion processing. An example of the configuration of the third processing unit 9 will be described with reference to FIG. FIG. 14 is a schematic diagram illustrating an example of the configuration of the third processing unit 9.

  As shown in FIG. 14, the third processing unit 9 includes a base 92 and a hot plate 93 in the third chamber 91. The base 92 is installed at the bottom of the third chamber 91 and supports the hot plate 93 at a predetermined height.

  The hot plate 93 includes a heating unit 931 inside. In addition, support pins 932 for supporting the wafer W are provided on the upper surface of the heating unit 931.

  In the substrate cleaning apparatus 7 ′ according to the fifth embodiment, after the first carry-out process shown in Step S <b> 106 of FIG. 5, the wafer W is loaded into the third processing unit 9 by the substrate transfer device 31 and the hot plate 93. Is placed on the support pin 932. Thereafter, in the third processing unit 9, the hot plate 93 heats the wafer W. Thereby, the topcoat liquid is heated together with the wafer W, and the volatilization of the volatile components is promoted.

  As described above, the substrate cleaning apparatus may include a first processing unit that performs the processing liquid supply process for film formation, a second processing unit that performs the removal liquid supply process, and a third processing unit that performs the volatilization promotion process. Good.

  The configuration of the third processing unit 9 is not limited to that shown in FIG. For example, the third processing unit 9 includes a substrate holding unit similar to the second substrate holding unit 62 included in the second processing unit 6, and supplies high-temperature N 2 gas to the back surface of the wafer W from the gas supply unit, The structure which heats the wafer W may be sufficient. Moreover, the 3rd process part 9 may be a structure provided with an airflow formation unit, a decompression device, an ultraviolet irradiation part, etc. as a volatilization promotion part.

  Further, in each of the embodiments described above, the chemical processing and the film-forming processing liquid supply processing are performed in the first processing unit. However, the chemical processing is performed separately from the first processing unit. It may be performed as a unit. Moreover, it is good also as performing a chemical | medical solution process in a 2nd process part. In such a case, the liquid supply unit 53 and the like may be provided in the second processing unit.

  Further, in each of the embodiments described above, the example in the case where the top coat solution and the alkaline developer are supplied to the main surface of the wafer W has been shown. However, the first processing unit and the second processing unit You may supply a topcoat liquid and an alkali developing solution to both surfaces. In such a case, the first processing unit and the second processing unit include a mechanical chuck such as the second substrate holding unit 62, and the top coat solution and the alkaline developer may be supplied from the fluid supply unit, respectively.

  By providing an under plate that covers the lower surface of the wafer W, the gap formed between the wafer W and the under plate can be filled with a top coat solution or an alkali developer. It can be efficiently spread on the back surface of the wafer W. Moreover, when providing an underplate in the 1st process part 5, a heating part may be provided in an underplate and a volatilization promotion process may be performed using this heating part.

(Other embodiments)
In each of the above-described embodiments, the example in which the topcoat liquid is used as the film-forming treatment liquid has been described. However, the film-forming treatment liquid is not limited to the 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 reflection of the main surface of the wafer W and increasing the transmittance. When such an antireflection film liquid is used as a film-forming treatment liquid, DIW 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. As described above, 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 metal-based contaminant (particle). It is. 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 as compared with the chemical solution in the normal chemical cleaning in which cleaning is performed using only the chemical action of the chemical solution. For this reason, it is possible to perform more effective particle removal while suppressing erosion to the base film as compared with general 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 alkali developer, it is possible to suppress surface roughness of the wafer main surface due to the alkali developer.

  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, an example in which the first processing unit 5 and the second processing unit 6 are accommodated in different chambers (the first chamber 51 and the second chamber 61) has been described. The first processing unit 5 and the second processing unit 6 may be accommodated in one chamber.

  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 first processing unit 6 second processing unit 7 substrate cleaning device 8 control device 9 third processing unit 52 first substrate holding unit 521 suction holding unit 53, 54, 55 liquid supply unit 62 second substrate holding unit 621 rotation Holding mechanism 621a Grasping part 622 Fluid supply part 63 Liquid supply part 100 Substrate cleaning system

Claims (1)

A first processing unit that includes a first holding unit that holds the substrate, and a first supply unit that contains a volatile component and supplies a processing liquid for forming a film over the entire main surface of the substrate to the substrate;
All of films formed by solidifying or curing on the substrate by volatilization of the volatile component from the processing liquid supplied to the substrate by the first supply unit and a second holding unit that holds the substrate And a second supply unit for supplying a rinsing liquid for removing the dissolved film remaining on the substrate and the removing liquid from the substrate to the substrate. A processing unit and
The first processing unit includes:
A substrate cleaning system comprising a processing liquid recovery cup for recovering the processing liquid.

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