Substrate processing method, storage medium, and substrate processing apparatus

Abstract

This invention provides a substrate processing method, a storage medium, and a substrate processing apparatus, which are effective in suppressing pattern collapse of resist patterns. One aspect of the substrate processing method includes: supplying a developing solution for forming a resist pattern to the surface of a substrate on which a resist film is formed; performing a multiple cleaning process, wherein the cleaning process involves supplying a modifying liquid containing a modifier having a hydrophilic group to the surface of the substrate on which the resist pattern is formed and supplying a rinsing solution for removing the modifying liquid to the surface of the substrate; and drying the surface of the substrate after performing the multiple cleaning processes.

Description

Technical Field

[0001] This disclosure relates to a substrate processing method, a storage medium, and a substrate processing apparatus. Background Technology

[0002] Patent Document 1 discloses a method for developing a resist film on a substrate (substrate processing method). The substrate processing method includes the following steps: supplying a developing solution to form a resist pattern on the substrate; coating the developed substrate with an aqueous solution of a water-soluble polymer; and supplying a rinsing solution to the substrate coated with the above-mentioned aqueous solution to clean the substrate.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2018 / 116985 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] This disclosure provides a substrate processing method, storage medium, and substrate processing apparatus that are effective in suppressing pattern collapse of resist patterns.

[0008] Solution for solving the problem

[0009] One aspect of this disclosure relates to a substrate processing method comprising: supplying a developing solution for forming a resist pattern to the surface of a substrate on which a resist film is formed; performing multiple cleaning processes, said cleaning processes being a process of supplying a modifying liquid containing a modifier having a hydrophilic group to the surface of the substrate on which the resist pattern is formed and supplying a rinsing solution for removing the modifying liquid to the surface of the substrate; and drying the surface of the substrate after performing the multiple cleaning processes.

[0010] The effects of the invention

[0011] According to this disclosure, a substrate processing method, a storage medium, and a substrate processing apparatus are provided that are effective in suppressing pattern collapse of resist patterns. Attached Figure Description

[0012] Figure 1 This is a schematic diagram illustrating the general structure of a substrate processing system.

[0013] Figure 2 This is a schematic diagram illustrating the internal structure of a coating and developing apparatus.

[0014] Figure 3 This is a schematic diagram illustrating the structure of a developing unit.

[0015] Figure 4 It is a block diagram illustrating the functional structure of the control device.

[0016] Figure 5 This is a graph illustrating an example of the control of rotational speed during the developing process.

[0017] Figure 6 This is a block diagram illustrating the hardware structure of the control device.

[0018] Figure 7 This is a flowchart illustrating an example of the developing process.

[0019] Figure 8 This is a flowchart illustrating an example of a cleaning process.

[0020] Figure 9 (a) and Figure 9 (b) is a schematic diagram illustrating the supply of the modified liquid during the cleaning process.

[0021] Figure 10 (a) and Figure 10 (b) is a schematic diagram illustrating the removal of the modified liquid during the cleaning process.

[0022] Figure 11 (a) and Figure 11 (b) is a schematic diagram showing the reaction of the resist pattern surface caused by the modified liquid.

[0023] Explanation of reference numerals in the attached figures

[0024] 1: Substrate processing system; 2: Coating and developing apparatus; 20: Rotation holding unit; 30: Developer supply unit; 50: Modifier supply unit; 52: Nozzle; 60: Rinse solution supply unit; 62: Nozzle; 70: Solution supply unit; 100: Control device; 102: Developing control unit; 106: Cleaning control unit; 108: Replacement control unit; 110: Drying control unit; W: Wafer; Wa: Surface; U3: Developing unit. Detailed Implementation

[0025] Hereinafter, one embodiment will be described with reference to the accompanying drawings. In the description, the same reference numerals are used to label the same elements or elements having the same function to omit repeated descriptions.

[0026] [Substrate Processing System]

[0027] First, refer to Figure 1 and Figure 2The following describes the general structure of the substrate processing system 1 (substrate processing apparatus). The substrate processing system 1 is a system for forming a photosensitive coating on a substrate, exposing the photosensitive coating, and developing the photosensitive coating. The substrate to be processed is, for example, a semiconductor wafer W. The photosensitive coating is, for example, a resist film. The substrate processing system 1 includes a coating and developing apparatus 2, an exposure apparatus 3, and a control device 100. The exposure apparatus 3 is an apparatus for exposing the resist film (photosensitive coating) formed on the wafer W (substrate). Specifically, the exposure apparatus 3 irradiates the exposed portion of the resist film with energy rays for exposure using methods such as immersion exposure. The coating and developing apparatus 2 forms a resist film by coating a resist (solution) on the surface of the wafer W (substrate) before the exposure process performed by the exposure apparatus 3. Furthermore, the coating and developing apparatus 2 develops the resist film after the exposure process.

[0028] (Coating and developing apparatus)

[0029] like Figure 1 and Figure 2 As shown, the coating and developing apparatus 2 (substrate processing apparatus) includes a carrier block 4, a processing block 5, and an interface block 6.

[0030] The carrier block 4 guides the wafer W into and out of the coating and developing apparatus 2. For example, the carrier block 4 can support multiple carriers C for the wafer W and has a built-in conveying device A1 including a transfer arm. The carriers C, for example, hold multiple circular wafers W. The conveying device A1 removes the wafer W from the carrier C and transfers it to the processing block 5, receives the wafer W from the processing block 5, and returns the wafer W to the carrier C. The processing block 5 has multiple processing modules 11, 12, 13, and 14.

[0031] Processing module 11 includes a coating unit U1, a heat treatment unit U2, and a conveying device A3 for transporting wafer W to these units. Processing module 11 forms a lower layer film on the surface of wafer W using the coating unit U1 and the heat treatment unit U2. The coating unit U1 coats the wafer W with a processing solution used to form the lower layer film. The heat treatment unit U2 performs various heat treatments accompanying the formation of the lower layer film. Examples of lower layer films include SOG (Spin On Glass) film, which is mainly composed of SiO2, and SiARC (Silicon-containing Anti-Reflective Coating).

[0032] Processing module 12 includes a coating unit U1, a heat treatment unit U2, and a transport device A3 for transporting wafer W to these units. Processing module 12 forms a resist film on a lower layer film using the coating unit U1 and the heat treatment unit U2. The coating unit U1 coats the lower layer film with a resist as a processing solution for forming the resist film. The heat treatment unit U2 performs various heat treatments accompanying the formation of the resist film. Thus, a resist film is formed on the surface of wafer W.

[0033] Processing module 13 includes a coating unit U1, a heat treatment unit U2, and a conveying device A3 for transporting wafer W to these units. Processing module 13 forms an upper film on the resist film using the coating unit U1 and the heat treatment unit U2. The coating unit U1 coats the resist film with a processing solution used to form the upper film. The heat treatment unit U2 performs various heat treatments accompanying the formation of the upper film.

[0034] Processing module 14 includes a developing unit U3, a heat treatment unit U4, and a transport device A3 for transporting wafer W to these units. Processing module 14 performs development processing on the exposed resist film using the developing unit U3 and the heat treatment unit U4. The developing unit U3 coats the surface of the exposed wafer W with a developer. Furthermore, the developing unit U3 performs a rinsing process to remove the coated developer using a rinsing solution or the like. Details of the rinsing process will be described later. The heat treatment unit U4 performs various heat treatments accompanying the development process. Specific examples of heat treatments accompanying the development process include pre-development heat treatment (PEB: Post Exposure Bake) and post-development heat treatment (PB: Post Bake).

[0035] A rack unit U10 is provided on the side of the support block 4 within the processing block 5. The rack unit U10 is divided into multiple layers arranged in the vertical direction. A conveying device A7, including a lifting arm, is provided near the rack unit U10. The conveying device A7 moves the wafer W up and down between the layers of the rack unit U10.

[0036] A frame unit U11 is provided on the side of the interface block 6 within the processing block 5. The frame unit U11 is divided into multiple layers arranged in the vertical direction.

[0037] Interface block 6 and exposure apparatus 3 exchange wafer W. For example, interface block 6 has a built-in transfer device A8 including a transfer arm and is connected to exposure apparatus 3. Transfer device A8 transfers wafer W, which is disposed in rack unit U11, to exposure apparatus 3. Transfer device A8 receives wafer W from exposure apparatus 3 and returns wafer W to rack unit U11.

[0038] (Developing unit)

[0039] Next, refer to Figure 3 Let's take a clear example of the U3 shadow unit. For instance... Figure 3 As shown, the developing unit U3 includes, for example, a rotation holding part 20, a developing solution supply part 30, a modifying solution supply part 50, a rinsing solution supply part 60, and a solution supply part 70.

[0040] A rotation holding portion 20 holds and rotates the wafer W. The rotation holding portion 20 includes, for example, a holding portion 22 and a rotation drive portion 24. The holding portion 22 supports the center portion of the wafer W, which is horizontally arranged with its surface Wa facing upwards, and holds the wafer W, for example, by vacuum suction. The rotation drive portion 24 is, for example, an actuator powered by an electric motor, which rotates the holding portion 22 about a vertical axis Ax. Thus, the wafer W on the holding portion 22 rotates. The holding portion 22 may also hold the wafer W such that the center of the wafer W is approximately aligned with the axis Ax.

[0041] The developer supply unit 30 supplies developer (hereinafter referred to as "developer L1") to the surface Wa of the wafer W on which the resist film R is formed. Developer L1 is a solution used to form the resist pattern. For example, a solution containing tetramethylammonium hydroxide (TMAH) is used as developer L1. The developer supply unit 30 may also include a nozzle 32, a supply source 34, and a nozzle moving mechanism 36. The nozzle 32 sprays developer L1 onto the surface Wa of the wafer W. For example, the nozzle 32 is positioned above the wafer W and sprays developer L1 downwards. The supply source 34 supplies developer L1 to the nozzle 32 via a pump or the like (not shown). The nozzle moving mechanism 36 uses an electric motor or the like as a power source to move the nozzle 32 between a spray position above the wafer W and a retracted position away from that spray position. The spray position is, for example, vertically above the rotation center of the wafer W. Thus, developer L1 is supplied to the center (rotation center) of the wafer W.

[0042] The modification solution supply unit 50 supplies a modification solution (hereinafter referred to as "modification solution L2") to the surface Wa of the wafer W on which the resist pattern is formed. Modification solution L2 is a solution used to modify the surface of the resist pattern. In this specification, surface modification refers to making the surface hydrophilic (reducing the contact angle). The modification solution contains a modifier having a hydrophilic group. An example of a hydrophilic group is a hydroxyl (OH) group. The modifier may include a water-soluble polymer. An example of a water-soluble polymer is a homopolymer or copolymer of monomers containing a hydrophilic group, or a condensation polymer having a hydrophilic group, etc.

[0043] Specific examples of water-soluble polymers include acrylic acid, methacrylic acid, fluoroacrylic acid, perfluoroalkyl acids, vinyl alcohol, vinylpyrrolidone, acrylates, methacrylates, polyvinyl alcohol (including some saponified forms), polyacrylic acid, polymethacrylic acid, polyvinyl methyl ether, polyvinylpyrrolidone, polyethylene glycol, polyvinyl acetal (including some acetalized forms), polyethyleneimine, polyethylene oxide, styrene-maleic anhydride copolymer, polyvinylamine, polyallylamine, water-soluble resins containing oxazoline groups, water-soluble melamine resins, water-soluble urea resins, alkyd resins or sulfonamides, and salts made from these water-soluble polymers. Additionally, polyglycerol can be used as a water-soluble polymer. These water-soluble polymers can be used alone or in combination of two or more. The concentration of the modifier (water-soluble polymer) in the modified liquid L2 can be less than 10% or less than 5%. A surfactant can be added to the modified liquid L2. The concentration of the surfactant can be less than 5%. The modified solution L2 can be acidic, for example, the pH of the modified solution L2 can be 3 to 6.

[0044] The modified liquid supply unit 50 may include a nozzle 52 (a nozzle for modified liquid), a supply source 54, and a nozzle moving mechanism 56. The nozzle 52 sprays modified liquid L2 onto the surface Wa of the wafer W. For example, the nozzle 52 is positioned above the wafer W, spraying modified liquid L2 downwards. The supply source 54 supplies modified liquid L2 to the nozzle 52 via a pump or the like (not shown). The nozzle moving mechanism 56 uses an electric motor or the like as a power source to move the nozzle 52 between a spraying position above the wafer W and a retracted position away from that spraying position. The spraying position is, for example, vertically above the rotation center of the wafer W. Thus, modified liquid L2 is supplied to the center (rotation center) of the wafer W.

[0045] The rinsing solution supply unit 60 can also supply rinsing solution (hereinafter referred to as "rinsing solution L3") to the surface Wa of the wafer W to which developer L1 has been supplied. The rinsing solution supply unit 60 supplies rinsing solution L3 to the surface Wa of the wafer W to which modifier L2 has been supplied. The rinsing solution L3 is a solution for removing modifier L2 (developer L1) from the surface Wa. Furthermore, removing modifier L2 (developer L1) includes replacing the modifier L2 (developer L1) on the surface Wa with rinsing solution L3. The rinsing solution L3 is, for example, an aqueous cleaning solution. As an example, the rinsing solution L3 is pure water, but DIW (Deionized Water) can also be used as the rinsing solution L3.

[0046] The rinsing fluid supply unit 60 may include a nozzle 62 (rinsing fluid nozzle), a supply source 64, and a nozzle moving mechanism 66. The nozzle 62 sprays rinsing fluid L3 onto the surface Wa of the wafer W. For example, the nozzle 62 is positioned above the wafer W, spraying the rinsing fluid L3 downwards. The supply source 64 supplies the rinsing fluid L3 to the nozzle 62 via a pump or the like (not shown). The nozzle moving mechanism 66 uses an electric motor or the like as a power source to move the nozzle moving mechanism 66 between a spraying position above the wafer W and a retracted position away from that spraying position. The spraying position is, for example, vertically above the rotation center of the wafer W. Thus, rinsing fluid L3 is supplied to the center (rotation center) of the wafer W.

[0047] The solution supply unit 70 supplies a solution containing a surfactant (hereinafter referred to as "solution L4") to the surface Wa of the wafer W. The solution supply unit 70 replaces the rinsing liquid L3 on the surface Wa with solution L4 by supplying solution L4. Examples of surfactants included in solution L4 include sorbitan monooleate, glycerol α-monooleate, polyethylene glycol dehydrated sorbitan fatty acid ester, polyethylene glycol linear alkyl ether, polyethylene glycol phenyl ether linear alkyl addition type, branched alkyl addition type, acetylenide glycol, anionic sodium laurate, sodium stearate, sodium oleate, sodium dodecyl sulfate, or sodium dodecylbenzene sulfonate. These surfactants can be used alone or in combination. The concentration of the surfactant in solution L4 can be less than 5%.

[0048] The solution supply unit 70 may include a nozzle 72, a supply source 74, and a nozzle moving mechanism 76. The nozzle 72 sprays solution L4 onto the surface Wa of the wafer W. For example, the nozzle 72 is positioned above the wafer W, spraying solution L4 downwards. The supply source 64 supplies solution L4 to the nozzle 72 via a pump or the like (not shown). The nozzle moving mechanism 76 uses an electric motor or the like as a power source to move the nozzle 72 between a spraying position above the wafer W and a retracted position away from that spraying position. The spraying position is, for example, vertically above the rotation center of the wafer W. Thus, solution L4 is supplied to the center (rotation center) of the wafer W.

[0049] (Control device)

[0050] Next, the specific structure of the control device 100 will be illustrated. The control device 100 controls part or all of the coating and developing apparatus 2. The control device 100 is configured to perform the following controls: while the holding part 22 holds the wafer W, supplying developer L1 to the surface Wa of the wafer W through the developer supply part 30; while the holding part 22 holds the wafer W, performing multiple cleaning processes, wherein the cleaning processes involve supplying modified liquid L2 to the surface Wa of the wafer W through the modified liquid supply part 50 and supplying rinsing liquid L3 through the rinsing liquid supply part 60; and after performing multiple cleaning processes, continuing to hold the wafer W in the holding part 22 to allow the surface Wa of the wafer W to dry.

[0051] like Figure 4 As shown, the control device 100 has a functional structure (hereinafter referred to as "functional module") including a developing control unit 102, a rinsing control unit 104, a cleaning control unit 106, a replacement control unit 108, and a drying control unit 110.

[0052] While the wafer W with the resist film R formed is held by the holding part 22, the developing control unit 102 supplies developer L1 to the surface Wa of the wafer W via the developer supply unit 30. For example, the developing control unit 102 controls the nozzle moving mechanism 36 so that the nozzle 32 of the developer supply unit 30 is positioned on the axis Ax (ejection position). While rotating the wafer W by rotating the holding part 20, the developing control unit 102 controls the developer supply unit 30 to eject developer L1 from the nozzle 32 on the axis Ax toward the resist film R. The developing control unit 102 holds the wafer W, which has been supplied with developer L1, in a stationary state by the holding part 22 (rotating holding part 20) to maintain the liquid film of developer L1 formed on the surface Wa of the wafer W.

[0053] The rinsing control unit 104 can supply rinsing fluid L3 to the surface Wa of the wafer W where the resist pattern is formed via the rinsing fluid supply unit 60 to remove the developer L1 on the surface Wa. The rinsing control unit 104 controls, for example, the nozzle moving mechanism 66 so that the nozzle 62 of the rinsing fluid supply unit 60 is positioned on the axis Ax. While rotating the wafer W via the rotation holding unit 20, the rinsing control unit 104 controls the rinsing fluid supply unit 60 to supply rinsing fluid L3 to the surface Wa of the wafer W via the nozzle 62 on the axis Ax. While supplying rinsing fluid L3, the rinsing control unit 104 adjusts the rotation speed of the wafer W to replace the developer L1 on the wafer W with rinsing fluid L3.

[0054] As an example, such as Figure 5As shown, the rinsing control unit 104 starts supplying rinsing fluid L3 through the rinsing fluid supply unit 60 while the wafer W is rotating at a speed ω1 via the rotation holding unit 20. After starting to supply rinsing fluid L3, the rinsing control unit 104 continues to supply rinsing fluid L3 through the rinsing fluid supply unit 60 while increasing the rotation speed of the wafer W from the rotation speed ω1 to the rotation speed ω2. During the supply of rinsing fluid L3, the rinsing control unit 104 controls the rotation holding unit 20 to gradually decrease the rotation speed of the wafer W from the rotation speed ω2 to the rotation speed ω3. When the rotation speed of the wafer W reaches the rotation speed ω3, the rinsing control unit 104 stops supplying rinsing fluid L3 through the rinsing fluid supply unit 60. The rinsing fluid L3 supplied from the rinsing fluid supply unit 60 diffuses on the surface Wa of the wafer W as the wafer W rotates via the rotation holding unit 20.

[0055] The rotational speed ω1 is set to a low speed that minimizes the impact of rotation on the liquid mass reaching surface Wa when the rinsing fluid L3 is initially supplied. For example, the rotational speed ω1 is approximately 20 rpm to 200 rpm. The rotational speed ω1 can also be approximately 50 rpm to 150 rpm, or approximately 80 rpm to 120 rpm. The rotational speed ω2 is set to a speed sufficient to allow the rinsing fluid L3 reaching surface Wa to diffuse to the periphery of wafer W. For example, the rotational speed ω2 is approximately 1000 rpm to 1400 rpm. The rotational speed ω2 can also be approximately 1100 rpm to 1300 rpm, or approximately 1150 rpm to 1250 rpm. The rotational speed ω3 is set according to the processing performed after the supply of rinsing fluid L3. The rotational speed ω3 can also be the same as the rotational speed ω1.

[0056] The cleaning control unit 106 performs multiple cleaning processes while the holding unit 22 holds the wafer W. These cleaning processes involve supplying a modified liquid L2 to the surface Wa of the wafer W via a modified liquid supply unit 50 and a rinsing liquid L3 via a rinsing liquid supply unit 60. In at least one of these multiple cleaning processes, after supplying the modified liquid L2 to the surface Wa of the wafer W and before supplying the rinsing liquid L3, the cleaning control unit 106 controls the developing unit U3 to increase the concentration of the modifier in the modified liquid L2 supplied to the surface Wa. For example, the cleaning control unit 106 controls the developing unit U3 to promote the evaporation of the solvent in the modified liquid L2 supplied to the surface Wa.

[0057] The cleaning control unit 106 can supply the modification liquid L2 from the same nozzle 52 and the rinsing liquid L3 from the same nozzle 62 during multiple cleaning processes. For example, when performing two cleaning processes, the cleaning control unit 106 uses the same nozzle 52 (nozzle 62) to supply the modification liquid L2 (rinsing liquid L3) to the wafer W in both the first and second cleaning processes. Furthermore, the cleaning control unit 106 performs multiple cleaning processes while the wafer W is placed in the same position. For example, the cleaning control unit 106 can repeatedly perform cleaning processes while the wafer W is held in the same rotating holding part 20 (holding part 22) within the developing unit U3. The cleaning control unit 106 includes, for example, a modification control unit 112, a promotion control unit 114, and a removal control unit 116.

[0058] During the cleaning process, the modification control unit 112 controls the nozzle movement mechanism 56 to position the nozzle 52 of the modification liquid supply unit 50 on the axis Ax. While rotating the wafer W via the rotation holding unit 20, the modification control unit 112 controls the modification liquid supply unit 50 to supply modification liquid L2 to the surface Wa of the wafer W via the nozzle 52 on the axis Ax (ejection position). While supplying modification liquid L2, the modification control unit 112 adjusts the rotation speed of the wafer W to replace the rinsing liquid L3 on the wafer W with modification liquid L2. For example, as... Figure 5 As shown, while the wafer W is rotating at a speed of ω3 via the rotation holding unit 20, the modification control unit 112 begins supplying modification liquid L2 via the modification liquid supply unit 50. After the supply of modification liquid L2 begins, the modification control unit 112 increases the rotation speed of the wafer W to a speed ω4, which is higher than the rotation speed ω3, while the modification liquid supply unit 50 continues to supply modification liquid L2. The rotation speed ω4 is set to such that the modification liquid L2 reaching the surface Wa of the wafer W diffuses to the periphery of the wafer W. The rotation speed ω4 can be greater than the rotation speed ω2; for example, it is approximately 1300 rpm to 1700 rpm. The rotation speed ω4 can be approximately 1400 rpm to 1600 rpm, or approximately 1450 rpm to 1550 rpm.

[0059] The modification control unit 112 can supply the modification liquid L2 to the nozzle 52 at the same flow rate or at the same supply time during multiple cleaning processes. The modification control unit 112 can change at least one of the flow rate and supply time in any cleaning process after the second one. For example, the modification control unit 112 can reduce at least one of the flow rate and supply time compared to the first cleaning process in any cleaning process after the second one. Furthermore, when the developing unit U3 has a nozzle for the modification liquid that is separate from the nozzle 52, the modification control unit 112 supplies the modification liquid L2 from different nozzles for the modification liquid during multiple cleaning processes.

[0060] In at least one cleaning process, the acceleration control unit 114 increases the concentration of the modifier in the modification liquid L2 by promoting the evaporation of the solvent in the modification liquid L2 on the surface Wa. For example, in this cleaning process, the acceleration control unit 114 rotates the wafer W by rotating the holding unit 20 without supplying any solution, thereby promoting the evaporation of the solvent in the modification liquid L2. As an example, the acceleration control unit 114 promotes the evaporation of the solvent to the point that solvent remains in the modification liquid L2 and the concentration of the modification liquid L2 increases. The time for the acceleration control unit 114 to rotate the wafer W to promote the evaporation of the solvent can be longer than the time for the modification control unit 112 to supply the modification liquid L2.

[0061] For example, Figure 5 As shown, after stopping the supply of the modified liquid L2, the acceleration control unit 114 controls the rotation holding unit 20 to reduce the rotation speed of the wafer W from rotation speed ω4 to rotation speed ω5, and then increase the rotation speed of the wafer W from rotation speed ω5 to rotation speed ω6. For example, the rotation speed ω5 is approximately 300 rpm to 700 rpm. The rotation speed ω5 can be approximately 400 rpm to 600 rpm, or approximately 450 rpm to 550 rpm. The rotation speed ω6 is set to the degree to which the solvent of the modified liquid L2 remains on the surface Wa. For example, the rotation speed ω6 can be the same as the rotation speed ω2. Furthermore, the acceleration control unit 114 may not rotate the wafer W, but continue to supply the modified agent to the modified liquid L2 after the modified liquid L2 has diffused to approximately the entire surface of the wafer W, thereby increasing the concentration of the modified agent. Alternatively, the acceleration control unit 114 may also heat the modified liquid L2 on the surface Wa to evaporate the solvent.

[0062] The removal control unit 116 controls the nozzle movement mechanism 66 during the cleaning process to position the nozzle 62 of the rinsing fluid supply unit 60 on the axis Ax. While rotating the wafer W via the rotation holding unit 20, the removal control unit 116 controls the rinsing fluid supply unit 60 to supply rinsing fluid L3 to the surface Wa of the wafer W via the nozzle 62 on the axis Ax. For example, the removal control unit 116 begins supplying rinsing fluid L3 via the rinsing fluid supply unit 60 when the rotation speed of the rotation holding unit 20 is controlled to be zero (when the wafer W is stationary). The removal control unit 116 continues to supply rinsing fluid L3 via the rinsing fluid supply unit 60 while rotating the wafer W about the axis Ax passing through the supply position of rinsing fluid L3. The time for the removal control unit 116 to supply rinsing fluid L3 can be longer than the time for the evaporation of the solvent promoted by the promotion control unit 114.

[0063] The control unit 116 adjusts the rotation speed of the wafer W while supplying rinsing fluid L3, so as to replace the modification fluid L2 on the wafer W with rinsing fluid L3. As an example, such as... Figure 5As shown, after the flushing fluid L3 is supplied, the control unit 116 gradually increases the rotational speed from zero to rotational speed ω7, and then increases it from rotational speed ω7 to rotational speed ω8 in a short time. The time for the rotational speed to increase from zero to rotational speed ω7 can be longer than the time for the rotational speed ω7 to increase to rotational speed ω8, for example, it can be about 2 to 20 times longer. The rotational speed ω7 can be the same as the rotational speed ω1 (rotational speed ω3). The rotational speed ω8 can be the same as the rotational speed ω2 (rotational speed ω6).

[0064] The removal control unit 116 controls the rotation holding unit 20 to change (reduce) the rotation speed of the wafer W from rotation speed ω8 to rotation speed ω9 until the supply of rinsing fluid L3 ends. When the rotation speed of the wafer W reaches rotation speed ω9, the removal control unit 116 stops the supply of rinsing fluid L3 by the rinsing fluid supply unit 60. The rotation speed ω9 is set according to the subsequent processing after the supply of rinsing fluid L3 ends. As an example, the rotation speed ω9 is the same as the rotation speed ω3. In this case, the removal control unit 116 changes the rotation speed of the wafer W during the supply of rinsing fluid L3 by the rotation holding unit 20 so that the rotation speed of the wafer W at the time when the supply of rinsing fluid L3 ends is consistent with the rotation speed of the wafer W at the time when the supply of modified liquid L2 begins in the next cleaning process. Hereinafter, the control of changing the rotation speed of the wafer W from rotation speed ω8 to rotation speed ω3 during the supply of rinsing fluid L3 will be referred to as "rotation speed change control".

[0065] The removal control unit 116 can control the rotation speed during the supply of rinsing fluid L3 in each of the multiple cleaning processes. Alternatively, the removal control unit 116 can also control the rotation speed during at least one of the multiple cleaning processes. Furthermore, if the removal control unit 116 does not control the rotation speed, the modification control unit 112 can adjust the rotation of the wafer W to a rotation speed ω1 via the rotation holding unit 20 after the supply of rinsing fluid L3 ends and before the next cleaning process begins.

[0066] Furthermore, when the developing unit U3 has a separate nozzle for rinsing liquid from the nozzle 62, the removal control unit 116 can supply modified liquid L2 from different modified liquid nozzles during multiple cleaning processes. During the supply of rinsing liquid during multiple cleaning processes and during the supply of rinsing liquid prior to multiple cleaning processes, the control device 100 can supply rinsing liquid from different rinsing liquid nozzles (different rinsing liquid supply units), and can also supply different types of rinsing liquid.

[0067] Before drying the surface Wa of the wafer W that has undergone multiple cleaning processes, the replacement control unit 108 controls the developing unit U3 to replace the rinsing liquid L3 on the surface Wa of the wafer W with a solution L4 containing a surfactant. The replacement of rinsing liquid L3 with solution L4 also includes removing at least a portion of the rinsing liquid L3 from the surface Wa of the wafer W, resulting in a mixture of rinsing liquid L3 and solution L4 on the surface Wa. The replacement control unit 108, for example, controls the nozzle moving mechanism 76 to position the nozzle 72 of the solution supply unit 70 on the axis Ax. While rotating the wafer W via the rotation holding unit 20, the replacement control unit 108 controls the solution supply unit 70 to supply solution L4 to the surface Wa of the wafer W via the nozzle 72 on the axis Ax. The replacement control unit 108 adjusts the rotation speed of the wafer W while supplying solution L4 to replace the rinsing liquid L3 on the wafer W with solution L4. For example, the replacement control unit 108 continues to supply solution L4 while rotating the wafer W at a rotation speed ω10. The rotational speed ω10 is set to the extent that the solution L4 can diffuse to the periphery of the wafer W, and for example, it is the same as the rotational speed ω5.

[0068] After the cleaning control unit 106 performs multiple cleaning processes, the drying control unit 110 continues to hold the wafer W in the holding unit 22 without supplying any solution, so that the surface Wa of the wafer W dries (removing the liquid filling the recesses of the resist pattern). For example, the drying control unit 110 removes the solution L4 from the surface Wa of the wafer W while rotating the holding unit 20 at a rotational speed ω11. The rotational speed ω11 is set to the extent that the solution L4 on the surface Wa is bounced towards the outer periphery of the wafer W. As an example, the rotational speed ω11 is the same as the rotational speed ω4.

[0069] The control device 100 comprises one or more control computers. For example, the control device 100 has... Figure 6 The circuit 120 shown has one or more processors 122, a memory 124, a storage device 126, and an input / output port 128. The storage device 126 has a computer-readable storage medium, such as a hard disk. The storage medium stores a program for causing the control device 100 to execute the substrate processing procedure (development process) described later. The storage medium can be a removable medium such as a non-volatile semiconductor memory, a magnetic disk, or an optical disk. The memory 124 temporarily stores the program loaded from the storage medium of the storage device 126 and the calculation results obtained by the processor 122. The processor 122 and the memory 124 cooperate to execute the program, thereby constituting the functional modules described above. The input / output port 128 performs electrical signal input / output with the controlled component according to instructions from the processor 122.

[0070] When the control device 100 is composed of multiple control computers, the developing control unit 102, rinsing control unit 104, cleaning control unit 106 (modification control unit 112, acceleration control unit 114, and removal control unit 116), replacement control unit 108, and drying control unit 110 can each be implemented by a separate control computer. Alternatively, each of these functional modules can be implemented by a combination of two or more control computers. In these cases, the multiple control computers cooperate to execute the substrate processing process described later, connected in a manner that allows them to communicate with each other. Furthermore, the hardware structure of the control device 100 is not necessarily limited to configuring each functional module through a program. For example, each functional module of the control device 100 can be composed of dedicated logic circuits or ASICs (Application Specific Integrated Circuits) obtained by integrating such logic circuits.

[0071] [Substrate Processing]

[0072] Next, as an example of a substrate processing method, the substrate processing process performed in the substrate processing system 1 will be described. The control device 100 controls the substrate processing system 1, for example, to perform substrate processing including coating and developing processes through the following steps. First, the control device 100 controls the transport device A1 to transport the wafer W in the carrier C to the rack unit U10, and controls the transport device A7 to arrange the wafer W in the layer for the processing module 11.

[0073] Next, the control device 100 controls the transfer device A3 to transfer the wafer W from the rack unit U10 to the coating unit U1 and the heat treatment unit U2 within the processing module 11. Additionally, the control device 100 controls the coating unit U1 and the heat treatment unit U2 to form a lower layer film on the surface Wa of the wafer W. Afterward, the control device 100 controls the transfer device A3 to return the wafer W with the lower layer film formed to the rack unit U10, and controls the transfer device A7 to place the wafer W into the layer grid used in the processing module 12.

[0074] Next, the control device 100 controls the transfer device A3 to transfer the wafer W from the rack unit U10 to the coating unit U1 and the heat treatment unit U2 within the processing module 12. Additionally, the control device 100 controls the coating unit U1 and the heat treatment unit U2 to form a resist film R on the lower layer of the wafer W. Afterward, the control device 100 controls the transfer device A3 to return the wafer W to the rack unit U10, and controls the transfer device A7 to place the wafer W in the layer for the processing module 13.

[0075] Next, the control device 100 controls the conveying device A3 to transport the wafer W from the rack unit U10 to the respective units within the processing module 13. Additionally, the control device 100 controls the coating unit U1 and the heat treatment unit U2 to form an upper film on the resist film R of the wafer W. Afterward, the control device 100 controls the conveying device A3 to transport the wafer W to the rack unit U11.

[0076] Next, the control device 100 controls the transport device A8 to deliver the wafer W housed in the rack unit U11 to the exposure apparatus 3. Furthermore, in the exposure apparatus 3, the resist film R formed on the wafer W is exposed. Afterward, the control device 100 controls the transport device A8 to receive the exposed wafer W from the exposure apparatus 3 and arrange the wafer W in the layer of the processing module 14 in the rack unit U11.

[0077] Next, the control device 100 controls the conveying device A3 to convey the wafer W from the rack unit U11 to the heat treatment unit U4 of the processing module 14. Furthermore, the control device 100 controls the execution of a processing procedure including heat treatment, development treatment, and rinsing treatment (hereinafter referred to as the "development process"). As a result, a resist pattern is formed on the surface Wa of the wafer W. Details of the development process will be described later. Afterward, the control device 100 controls the conveying device A3 to return the developed wafer W to the rack unit U10, and controls the conveying devices A7 and A1 to return the wafer W to the carrier C. Through the above process, the coating and development process is completed.

[0078] (Developing process)

[0079] Next, refer to Figures 7-10 (b) is a clear example of the impact on the processing. Figure 7 This is a flowchart illustrating an example of the developing process. First, the control device 100 executes step S01. In step S01, for example, the control device 100 controls the processing unit U4 to perform heat treatment on the wafer W, which has undergone exposure processing, at a predetermined temperature for a predetermined time. Then, the control device 100 controls the transport device A3 to transport the wafer W, which has undergone heat treatment before developing, to the developing unit U3.

[0080] Next, the control device 100 executes step S02. In step S02, for example, the developing control unit 102, while holding the wafer W with the resist film R formed on it by the holding part 22, supplies developing solution L1 to the surface Wa of the wafer W through the developing solution supply unit 30. Specifically, the developing control unit 102 controls the nozzle moving mechanism 36 to position the nozzle 32 of the developing solution supply unit 30 on the axis Ax. Then, while rotating the wafer W by rotating the holding part 20, the developing control unit 102 controls the developing solution supply unit 30 to spray developing solution L1 from the nozzle 32 on the axis Ax toward the surface Wa of the wafer W with the resist film R formed. After supplying developing solution L1, the developing control unit 102 can hold the wafer W in a stationary state by the rotating holding part 20 (holding part 22), thereby developing the resist film R. As a result, a resist pattern is formed on the surface Wa of the wafer W.

[0081] Next, the control device 100 executes step S03. In step S03, for example, the rinsing control unit 104 controls the rinsing fluid supply unit 60 to supply rinsing fluid L3 to the surface Wa on which the resist pattern is formed. Specifically, the rinsing control unit 104 controls the nozzle moving mechanism 66 to position the nozzle 62 of the rinsing fluid supply unit 60 on the axis Ax. Then, while rotating the wafer W via the rotation holding unit 20, the rinsing control unit 104 controls the rinsing fluid supply unit 60 to supply rinsing fluid L3 to the surface Wa of the wafer W via the nozzle 62 on the axis Ax. The rinsing control unit 104 can control the rotation holding unit 20 to change the rotation speed while supplying rinsing fluid L3. For example, the rinsing control unit 104 controls the rotation holding unit 20 to rotate the wafer W at a rotation speed ω1 when the supply of rinsing fluid L3 begins, and to increase the rotation speed of the wafer W to a rotation speed ω2 after the supply begins. Then, the rinsing control unit 104 controls the rotation holding unit 20 to gradually reduce the rotation speed of the wafer W from rotation speed ω2 to rotation speed ω3. When the rotation speed of the wafer W reaches rotation speed ω3, the rinsing fluid supply unit 60 stops supplying rinsing fluid L3.

[0082] Next, the control device 100 executes steps S04 and S05. In steps S04 and S05, for example, the cleaning control unit 106 performs multiple cleaning processes. Specific examples of multiple cleaning processes (cleaning procedures) will be described later. After the cleaning control unit 106 performs multiple cleaning processes, rinsing fluid L3 remains on the surface Wa (recess of the resist pattern) of the wafer W.

[0083] After performing a predetermined number of cleaning processes, the control device 100 executes step S06. In step S06, for example, the displacement control unit 108 controls the developing unit U3 to replace the rinsing liquid L3 on the surface Wa of the wafer W, which has undergone multiple cleaning processes, with a solution L4 containing a surfactant. Specifically, the displacement control unit 108 controls the nozzle moving mechanism 76 to position the nozzle 72 of the solution supply unit 70 on the axis Ax. Then, while rotating the wafer W at a rotational speed ω10 via the rotation holding unit 20, the displacement control unit 108 controls the solution supply unit 70 to supply solution L4 to the surface Wa of the wafer W via the nozzle 72 on the axis Ax. The displacement control unit 108 can continue supplying solution L4 for a predetermined time to a degree that the solution L4 is diffused substantially uniformly across the entire surface Wa of the wafer W, and after the predetermined time, stop the solution supply unit 70 from supplying solution L4.

[0084] Next, the control device 100 executes step S07. In step S07, for example, the drying control unit 110 dries the surface Wa of the wafer W held by the holding unit 22 (removing the liquid filling the recesses of the resist pattern). Specifically, the drying control unit 110 removes the solution L4 from the surface Wa of the wafer W while rotating the wafer W at a rotational speed ω11 via the rotating holding unit 20. The drying control unit 110 continues to rotate the wafer W for a predetermined time to ensure that no liquid (solution L4) remains on the surface Wa, and after the predetermined time, stops the rotation of the wafer W by the rotating holding unit 20.

[0085] Next, the control device 100 executes step S08. In step S08, for example, the control device 100 controls the heat treatment unit U4 to perform heat treatment on the wafer W with the resist pattern formed at a predetermined temperature for a predetermined time. Thus, the heat treatment after development is performed, and the development process ends.

[0086] (Cleaning process)

[0087] Figure 8 This is a flowchart illustrating an example of a cleaning process. In this cleaning process, the control device 100 first executes step S41 while the wafer W continues to rotate at a speed ω3 set by the rotation holding unit 20. In step S41, for example, the modification control unit 112 begins supplying modification liquid L2 to the surface Wa of the wafer W rotating at speed ω3 via the modification liquid supply unit 50. Specifically, as... Figure 9 As shown in (a), the modification control unit 112 controls the nozzle moving mechanism 56 to position the nozzle 52 of the modification liquid supply unit 50 on the axis Ax, and then causes the modification liquid supply unit 50 to start supplying modification liquid L2.

[0088] Next, the control device 100 executes steps S42 and S43. In step S42, for example, the modification control unit 112 controls the rotation holding unit 20 to increase the rotational speed of the wafer W from rotational speed ω3 to rotational speed ω4. Thus, as... Figure 9 As shown in (a), as the modified liquid L2 diffuses, the rinsing liquid L3 is gradually removed (replaced by the modified liquid L2). In step S43, the modification control unit 112 stops the supply of modified liquid L2 by the modified liquid supply unit 50.

[0089] Next, the control device 100 executes steps S44 and S45. In step S44, for example, the control unit 114 controls the rotation holding unit 20 to reduce the rotational speed of the wafer W from rotational speed ω4 to rotational speed ω5. Then, the control unit 114 controls the rotation holding unit 20 to increase the rotational speed of the wafer W from rotational speed ω5 to rotational speed ω6. Afterwards, as... Figure 9 As shown in (b), the acceleration control unit 114 controls the rotation holding unit 20 to keep the wafer W rotating at a rotational speed ω6. Specifically, the acceleration control unit 114 keeps the wafer W rotating at a rotational speed ω6 until a predetermined time has elapsed. The predetermined time is, for example, the time during which the concentration of the modifier in the modifier liquid L2 rises to the point where the modifier liquid L2 does not solidify. The predetermined time is, for example, approximately several seconds to tens of seconds.

[0090] After a predetermined time has elapsed, the control device 100 executes steps S46 and S47. In step S46, the control unit 116 stops controlling the rotation holding unit 20 to stop the wafer W from rotating (rotation speed is zero). In step S47, for example, the control unit 116 stops controlling the wafer W to rotate at zero speed (wafer W is stationary) and starts supplying the rinsing fluid supply unit 60 with the rinsing fluid L3. Specifically, as... Figure 10 As shown in (a), the removal control unit 116 controls the nozzle moving mechanism 66 to position the nozzle 62 of the rinsing fluid supply unit 60 on the axis Ax. Then, the removal control unit 116 controls the rinsing fluid supply unit 60 to supply rinsing fluid L3 to the surface Wa of the wafer W held by the rotating holding unit 20 via the nozzle 62 on the axis Ax.

[0091] Next, the control device 100 executes steps S48 and S49. In step S48, for example, the control unit 116 is deactivated to control the rotation holding unit 20, so that the wafer W can start rotating again and the rotation speed is changed. As an example, first, after the control unit 116 gradually accelerates the rotation of the wafer W to a rotation speed ω7, the rotation speed of the wafer W is briefly increased from rotation speed ω7 to rotation speed ω8. Thus, as Figure 10As shown in (b), the modified liquid L2 on the surface Wa of the wafer W is replaced with rinsing liquid L3 (removal of modified liquid L2). Then, the removal control unit 116 gradually reduces the rotation speed of the wafer W from rotation speed ω8 to rotation speed ω9. In step S49, for example, the removal control unit 116 stops the rinsing liquid supply unit 60 from supplying rinsing liquid L3.

[0092] After completing one cleaning process including steps S41 to S49, the control device 100 repeats the process of steps S41 to S49. Furthermore, the acceleration control unit 114 can perform the solvent evaporation promotion in steps S44 and S45 in each of the multiple cleaning processes, or it can perform steps S44 and S45 in only a portion of the multiple cleaning processes. Alternatively, the control device 100 may omit steps S44 and S45 in each cleaning process.

[0093] [Effects of the Implementation Method]

[0094] As described above, the substrate processing procedure includes: supplying a developer L1 for forming a resist pattern to the surface Wa of the wafer W on which the resist film R is formed; performing multiple cleaning processes, wherein the cleaning processes are a process of supplying a modifier L2 containing a modifier having a hydrophilic group to the surface Wa of the wafer W on which the resist pattern is formed and supplying a rinsing solution L3 for removing the modifier L2 to the surface Wa of the wafer W; and drying the surface Wa of the wafer W after performing multiple cleaning processes.

[0095] The substrate processing system 1 includes: a holding section 22 that holds a wafer W; a developer supply section 30 that supplies a developer L1 for forming a resist pattern to the surface Wa of the wafer W on which a resist film R is formed; a modifier supply section 50 that supplies a modifier L2 containing a hydrophilic modifier to the surface Wa of the wafer W on which a resist pattern is formed; a rinsing solution supply section 60 that supplies a rinsing solution L3 for removing the modifier L2 to the surface Wa of the wafer W; and a development control section 102 that, while the holding section 22 holds the wafer W, controls the development of the wafer W by passing the developer... The supply unit 30 supplies developer L1 to the surface Wa of the wafer W; the cleaning control unit 106 performs multiple cleaning processes while the holding unit 22 holds the wafer W, the cleaning processes being the supply of modified liquid L2 to the surface Wa of the wafer W by the modified liquid supply unit 50 and the supply of rinsing liquid L3 by the rinsing liquid supply unit 60; and the drying control unit 110, after the cleaning control unit 106 performs multiple cleaning processes, continues to hold the wafer W by the holding unit 22 without supplying liquid, so that the surface Wa of the wafer W dries.

[0096] When drying the surface Wa of wafer W, if the contact angle between the liquid on surface Wa and the surface of the resist pattern is large, liquid breakage will occur when the liquid is removed from surface Wa, resulting in a portion of the liquid being cut off. When liquid breakage occurs, liquid remains in a recess of a portion of the resist pattern, and the pattern collapses due to the surface tension of the liquid remaining in that area. In the above method (the above substrate processing system 1), the surface of the resist pattern is modified by repeatedly supplying the modifying liquid L2 through multiple cleaning processes. As a result, the possibility of liquid breakage occurring when removing liquid from wafer W is reduced. Therefore, it is effective in suppressing pattern collapse of the resist pattern. In addition, repeatedly supplying the modifying liquid L2 and removing it with rinsing liquid L3 is also useful for removing dissolution products generated during development.

[0097] Figure 11 (a) and Figure 11 (b) schematically illustrates the surface modification of the resist pattern by modifying liquid L2. Figure 11 (a) indicates the state of surface Wa after the first cleaning treatment. Figure 11 (b) indicates the state of surface Wa after a second or subsequent cleaning treatment (multiple cleaning treatments). Figure 11 As shown in (a), it can be assumed that during the first cleaning process, the surface of the resist pattern 200 reacts with the hydrophilic groups 202 in the modifying liquid L2, thereby forming a modified layer 204 on the portion of the resist pattern 200 where the reaction occurs. At this time, the modified layer 204 is formed in a sparse state on the resist pattern 200. Furthermore, a sparse state refers to a state where the surface area of ​​the modified layer 204 is small relative to the total surface area of ​​the resist pattern 200. In the sparse state, spots of the modified layer 204 are generated on the surface of the resist pattern 200.

[0098] After a modified layer 204 is formed in a sparse state on the surface of the resist pattern 200, when a second or subsequent cleaning process is performed, such as Figure 11As shown in (b), the modified layer 204 is formed in a dense state on the resist pattern 200. Furthermore, "dense state" refers to a state where the surface area of ​​the modified layer 204 is large relative to the total surface area of ​​the resist pattern 200. In subsequent cleaning processes, since the modified layer 204 has already formed in a portion of the resist pattern up to the previous cleaning process, it is considered that the modifier further penetrates to areas where the reaction has not progressed, and hydrophilicity also progresses in these areas. Thus, the modified layer 204 is uniformly formed on the surface of the resist pattern 200, and the thickness of the modified layer 204 gradually increases. It can be considered that by uniformly forming the modified layer 204 on the surface of the resist pattern 200, including the exposed portions between the resist patterns 200 in the surface Wa (underlying film), liquid breakage during liquid removal from the surface Wa can be suppressed. Furthermore, it can be considered that when the contact angle of the resist pattern 200 differs from the contact angle of the exposed portions of the underlying film, uniformity of the modified layer 204 is more useful.

[0099] The aforementioned modifiers may include water-soluble polymers. Water-soluble polymers contain a large number of hydrophilic groups, thus enabling efficient modification of the surface of resist patterns.

[0100] In at least one cleaning process, the concentration of the modifier may be increased after the modifier liquid L2 is supplied to the surface Wa of the wafer W and before the rinsing liquid L3 is supplied. In this case, by increasing the concentration of the modifier, the modification of the contact angle of the resist pattern surface is more reliably achieved. Therefore, it is more effective in suppressing pattern collapse of the resist pattern.

[0101] Increasing the concentration of the modifier can include promoting the evaporation of the solvent in the modified liquid L2. In this case, the concentration of the modifier in the modified liquid L2 can be increased using a simple device.

[0102] Supplying rinsing fluid L3 to the surface Wa of wafer W can include: starting to supply rinsing fluid L3 to the surface Wa of wafer W while wafer W is stationary; and continuing to supply rinsing fluid L3 while wafer W is rotating. When the supply of rinsing fluid L3 begins while wafer W is rotating, the liquid mass of rinsing fluid L3 adhering to the surface Wa of wafer W at the start of the supply is disturbed by the rotation. Therefore, the amount of liquid diffused to the periphery of wafer W varies in the circumferential direction of the substrate, which may produce removal spots of modified fluid L2. In the above method, by stopping wafer W, the liquid mass of rinsing fluid L3 adhering to the surface Wa is less likely to be disturbed, thus effectively suppressing the aforementioned removal spots.

[0103] Supplying the modification solution L2 to the surface Wa of wafer W can include supplying the modification solution L2 while rotating wafer W. Supplying the rinsing solution L3 while rotating wafer W can include changing the rotation speed of wafer W during the supply of rinsing solution L3, so that the rotation speed of wafer W at the point where the supply of rinsing solution L3 ends is consistent with the rotation speed of wafer W at the point where the supply of modification solution L2 begins in the subsequent cleaning process. In this case, there is no need to adjust the rotation speed of wafer W between the supply of rinsing solution L3 and the subsequent cleaning process. Therefore, it is possible to achieve both suppression and processing capabilities against pattern collapse.

[0104] The aforementioned substrate processing may further include replacing the rinsing solution L3 on the surface Wa of the wafer W, which has undergone multiple cleaning processes, with a solution L4 containing a surfactant before drying. Solution L4 has low surface tension, thus suppressing pattern collapse even if some of the solution L4 remains between the patterns during drying. Furthermore, on the surface of the resist pattern, the modification progresses gradually through multiple cleaning processes, allowing for more reliable replacement from rinsing solution L3 to solution L4. Therefore, this is more effective in suppressing pattern collapse.

[0105] In the aforementioned substrate processing, during multiple cleaning processes, the modified liquid L2 can be supplied from the same nozzle 52, and the rinsing liquid L3 can be supplied from the same nozzle 62. In this case, the apparatus for supplying the modified liquid L2 and the rinsing liquid L3 can be simplified.

[0106] In the aforementioned substrate processing, multiple cleaning processes can be performed while the wafer W is placed in the same position. In this case, there is no need to transfer the wafer W between multiple cleaning processes. Therefore, it is possible to achieve both suppression and handling capabilities for pattern collapse.

[0107] The embodiments have been described above, but this disclosure is not necessarily limited to the embodiments described above, and various modifications can be made without departing from its spirit. The substrate to be processed is not limited to semiconductor wafers, but may also be, for example, a glass substrate, a mask substrate, an FPD (Flat Panel Display), etc.

Claims

1. A substrate processing method, comprising: supplying a developing solution for forming a resist pattern to a surface of a substrate on which a resist film is formed; performing a plurality of cleaning processes to form a modified layer on the surface of the substrate, the cleaning process being a process of supplying a modifying solution containing a modifier having a hydrophilic group to the surface of the substrate on which the resist pattern is formed and supplying a rinsing solution for removing the modifying solution to the surface of the substrate; and drying the surface of the substrate after performing the plurality of cleaning processes, wherein the supplying of the rinsing solution to the surface of the substrate includes: starting the supplying of the rinsing solution to the surface of the substrate in a state where the substrate is stationary; and continuing the supplying of the rinsing solution while rotating the substrate, wherein, during the supplying of the modifying solution, the substrate is rotated at a first speed, and then rotated at a second speed higher than the first speed, and wherein, during the supplying of the rinsing solution, the supplying of the rinsing solution is started in a state where the rotation speed of the substrate is zero, and then the substrate is rotated and the rotation speed of the substrate is brought to a third speed higher than zero, and then the substrate is rotated at a fourth speed higher than the third speed.

2. The substrate processing method according to claim 1, wherein the modifier contains a water-soluble polymer.

3. The substrate processing method according to claim 1 or 2, wherein at least one of the cleaning processes further includes increasing the concentration of the modifier after the supplying of the modifying solution to the surface of the substrate and before the supplying of the rinsing solution.

4. The substrate processing method according to claim 3, wherein the increasing of the concentration of the modifier includes promoting the volatilization of a solvent of the modifying solution.

5. The substrate processing method according to claim 1, wherein the supplying of the modifying solution to the surface of the substrate includes supplying the modifying solution while rotating the substrate, the supplying of the rinsing solution while rotating the substrate includes changing the rotation speed of the substrate during the supplying of the rinsing solution so that the rotation speed of the substrate at the time point of ending the supplying of the rinsing solution coincides with the rotation speed of the substrate at the time point of starting the supplying of the modifying solution in the next cleaning process.

6. The substrate processing method according to claim 1 or 2, wherein before drying the surface of the substrate to which the plurality of cleaning processes are applied, further including replacing the rinsing solution on the surface of the substrate with a solution containing a surfactant.

7. The substrate processing method according to claim 1 or 2, wherein in the plurality of cleaning processes, the modifying solution is supplied from the same modifying solution nozzle, and the rinsing solution is supplied from the same rinsing solution nozzle.

8. The substrate processing method according to claim 1 or 2, wherein the plurality of cleaning processes are performed in a state where the substrate is placed at the same position.

9. A computer-readable storage medium, storing a program for causing an apparatus to perform the substrate processing method according to any one of claims 1 to 8.

10. A substrate processing apparatus comprising: a holding section that holds a substrate and rotates the substrate; a developer supply section that supplies a developer for forming a resist pattern to a surface of the substrate on which a resist film is formed; a modifying liquid supply section that supplies a modifying liquid containing a modifying agent having a hydrophilic group to the surface of the substrate on which the resist pattern is formed; a rinse liquid supply section that supplies a rinse liquid for removing the modifying liquid to the surface of the substrate; a control section that controls to perform the following processes: in a state where the holding section holds the substrate, the developer supply section supplies the developer to the surface of the substrate; in a state where the holding section holds the substrate, a plurality of cleaning processes are performed to form a modifying layer on the surface of the substrate, the cleaning process being a process in which the modifying liquid supply section supplies the modifying liquid to the surface of the substrate and the rinse liquid supply section supplies the rinse liquid, and after the plurality of cleaning processes are performed, the holding section continues to hold the substrate in a state where no liquid is supplied to dry the surface of the substrate, wherein the supply of the rinse liquid to the surface of the substrate includes: in a state where the substrate is stationary, the supply of the rinse liquid to the surface of the substrate is started, and the supply of the rinse liquid is continued while the substrate is rotated, wherein during the supply of the modifying liquid, the substrate is rotated at a first speed, and then the substrate is rotated at a second speed higher than the first speed, and wherein during the supply of the rinse liquid, the supply of the rinse liquid is started in a state where the rotation speed of the substrate is zero, and then the substrate is rotated and the rotation speed of the substrate reaches a third speed higher than zero, and then the substrate is rotated at a fourth speed higher than the third speed.

11. A computer program product including a program for causing an apparatus to execute the substrate processing method according to any one of claims 1 to 8.

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