Substrate processing method and substrate processing device

Abstract

The present invention provides a substrate processing method and a substrate processing device. The substrate processing method for processing a substrate includes: (a) applying a coating liquid to the surface of a substrate by spin coating to form a coating film; (b) supplying a solvent of the coating liquid to the convex portion of the coating film formed on the surface peripheral portion of the substrate in step (a); and (c) rotating the substrate while stopping the supply of the solvent to move the apex of the convex portion radially outward of the substrate, and repeating the steps (b) and (c). The present invention can remove the convex portion of the coating film formed on the surface peripheral portion of the substrate, so that the coating film is uniformly formed within the substrate surface.

Description

Technical Field

[0001] The present invention relates to a substrate processing method and a substrate processing device. Background Art

[0002] Patent Document 1 discloses a method in which, after a coating film is formed by discharging a coating liquid onto a wafer surface from a nozzle, an organic solvent is discharged from the nozzle onto a peripheral portion of the wafer surface, and the wafer is rotated at high speed for a short time.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-191853 Summary of the Invention

[0006] Technical problem to be solved by the invention

[0007] The technology of the present invention removes the protrusions of the coating film formed on the peripheral edge of the surface of the substrate, thereby forming the coating film uniformly within the substrate surface.

[0008] Technical solutions to technical problems

[0009] One embodiment of the present invention is a substrate processing method for processing a substrate, which includes: (a) a step of applying a coating liquid on the surface of a substrate by spin coating to form a coating film; (b) a step of supplying a solvent of the coating liquid to a convex portion of the coating film formed on the peripheral portion of the surface of the substrate in the above-mentioned step (a); and (c) a step of rotating the substrate while stopping the supply of the above-mentioned solvent to move the apex of the above-mentioned convex portion toward the radial outside of the substrate, and repeating the above-mentioned step (b) and the above-mentioned step (c).

[0010] Effects of the Invention

[0011] According to the present invention, it is possible to remove the protrusions of the coating film formed on the peripheral portion of the surface of the substrate, and form the coating film uniformly within the substrate surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a longitudinal sectional view schematically showing the configuration of the coating treatment apparatus according to this embodiment.

[0013] Figure 2 It is a cross-sectional view schematically showing the configuration of the coating treatment apparatus according to this embodiment.

[0014] Figure 3 These are explanatory diagrams schematically illustrating the state of the liquid film on the wafer in each step of the coating process.

[0015] Figure 4This is an explanatory diagram showing the state of a liquid film on the peripheral portion of the surface of a wafer when a conventional coating treatment method is performed.

[0016] Figure 5 It is an explanatory diagram showing the state of the liquid film on the peripheral portion of the surface of the wafer when the coating treatment method according to the first embodiment is performed.

[0017] Figure 6 This is a graph showing changes in the film thickness of the coating film at the peripheral portion of the surface of the wafer when the number of cycles is changed.

[0018] Figure 7 This is a graph showing changes in the film thickness of the coating film on the surface peripheral portion of the wafer when the supply time of the solvent is changed.

[0019] Figure 8 This is a graph showing changes in the film thickness of the coating film on the surface peripheral portion of the wafer when the supply position of the solvent is changed.

[0020] Figure 9 It is an explanatory diagram showing the state of the liquid film on the peripheral portion of the surface of the wafer when the coating treatment method according to the second embodiment is performed.

[0021] Figure 10 It is an explanatory diagram showing the state of the liquid film on the peripheral portion of the surface of the wafer when the coating treatment method according to the third embodiment is performed.

[0022] Figure 11 It is an explanatory diagram showing the state of the liquid film on the peripheral portion of the surface of the wafer when the coating treatment method according to the fourth embodiment is performed.

[0023] Description of Reference Numerals

[0024] 1 Coating treatment device

[0025] 20 Rotating chuck

[0026] 40 coating liquid nozzle

[0027] 50 1st solvent nozzle

[0028] 100 Control Department

[0029] W chip. DETAILED DESCRIPTION

[0030] In the photolithography process of the manufacturing process of semiconductor devices, a resist coating process is performed in which a resist liquid is coated on a semiconductor wafer (hereinafter referred to as a wafer) serving as a substrate to form a resist film, an exposure process is performed in which the resist film is exposed in a predetermined pattern, and a development process is performed in which the exposed resist film is developed, thereby forming a predetermined resist pattern on the wafer.

[0031] In the resist coating process described above, a so-called spin coating method is often used, in which resist liquid is supplied from a nozzle to the center of a rotating wafer, and the resist liquid is spread on the wafer by centrifugal force to coat the wafer.

[0032] However, in recent years, when manufacturing MEMS (Micro Electro Mechanical Systems), a relatively large resist film with a thickness of, for example, 20 to 80 μm is formed on the surface of a wafer. In this case, a high viscosity resist liquid of, for example, 1000 to 10000 cp can be used as the material for the resist film.

[0033] As described above, when a high-viscosity resist liquid is used to form a thick resist film, the resist liquid has difficulty flowing on the surface of the wafer, resulting in a convex protrusion (so-called hump) on the peripheral edge of the wafer surface, making the resist film particularly thick. Therefore, for example, in the method described in Patent Document 1, the hump on the peripheral edge of the resist film can be removed by releasing an organic solvent from a nozzle onto the peripheral edge of the wafer surface. Furthermore, by subsequently spinning the wafer briefly and at high speed (a so-called short spin), the organic solvent remaining on the surface of the resist film and any residue dissolved by the organic solvent are discharged from the surface of the resist film.

[0034] Furthermore, in the semiconductor device manufacturing process, after forming a device on the surface of a wafer, a protective film is formed to protect the device. This protective film has a high film thickness of, for example, about 20 μm to 80 μm, and the material of the protective film can be a high viscosity coating liquid of, for example, about 1000 cp to 10000 cp, such as photosensitive polyimide.

[0035] Furthermore, when a thick protective film is formed by spin coating using a high-viscosity coating liquid, a hump eventually forms on the peripheral edge of the wafer surface, similar to the resist film described above. As a countermeasure, for example, supplying an organic solvent to the peripheral edge of the wafer surface and briefly spinning the wafer can be considered to remove the hump.

[0036] However, when using an organic solvent to remove humps from coating films such as resists and protective films, it is difficult to optimize the timing and location of the organic solvent supply. Specifically, varying the timing and location of the organic solvent supply causes complex variations in the thickness of the coating film at the periphery, making its behavior difficult to predict. Consequently, setting the timing and location of the organic solvent supply requires repeated experimentation. Therefore, existing coating film formation methods leave room for improvement.

[0037] Therefore, the technology of the present invention removes the protrusions of the coating film formed on the peripheral edge of the surface of the substrate, and forms the coating film uniformly within the substrate surface.

[0038] Hereinafter, the substrate processing apparatus and substrate processing method of this embodiment will be described with reference to the accompanying drawings. In addition, in this specification and the accompanying drawings, elements having substantially the same functional configuration are denoted by the same reference numerals and repeated descriptions are omitted.

[0039] <Configuration of Coating Treatment Apparatus 1>

[0040] Figure 1 It is a longitudinal sectional view schematically showing the configuration of a coating processing apparatus 1 as a substrate processing apparatus according to the present embodiment. Figure 2 This is a cross-sectional view schematically illustrating the configuration of a coating processing apparatus 1 according to this embodiment. In the coating processing apparatus 1 according to this embodiment, a coating film is formed by applying a coating liquid to the surface of a wafer by spin coating. The following describes a case where the coating film is a protective film for devices (not shown) formed on the surface of the wafer W, and the coating liquid is, for example, a photosensitive polyimide having a high viscosity of approximately 1,000 to 10,000 cp.

[0041] like Figure 1 As shown, the coating treatment apparatus 1 includes a treatment container 10 capable of sealing the interior. Figure 2 As shown, a wafer W loading and unloading port 11 is formed on a side surface of the processing container 10 , and a shutter 12 is provided at the loading and unloading port 11 .

[0042] like Figure 1 As shown, a spin chuck 20 serving as a substrate holding portion for holding and rotating a wafer W is provided in the center of the processing chamber 10. The spin chuck 20 has a horizontal upper surface, and a suction port (not shown) is provided on the upper surface for sucking the wafer W. The wafer W can be held by suction on the spin chuck 20 by suction through the suction port.

[0043] A chuck driving unit 21 including, for example, a motor is provided below the rotary chuck 20. The rotary chuck 20 can be rotated at a predetermined speed by the chuck driving unit 21. Furthermore, a lifting drive source such as an air cylinder is provided in the chuck driving unit 21, so that the rotary chuck 20 can be raised and lowered.

[0044] A cup 22 is provided around the spin chuck 20 to collect and recover liquid scattered or dropped from the wafer W. A discharge pipe 23 for discharging the recovered liquid and an exhaust pipe 24 for exhausting the atmosphere within the cup 22 are connected to the bottom surface of the cup 22 .

[0045] like Figure 2 As shown, in the negative direction of the X direction of the cup-shaped body 22 ( Figure 2 The lower side of the Figure 2 The guide rail 30 extends from the negative direction of the Y direction ( Figure 2 The outer side of the left side is formed to the positive direction of the Y direction ( Figure 2 The guide rail 30 is provided with, for example, two support arms 31 and 32.

[0046] like Figure 1 and Figure 2 As shown, the first support arm 31 supports a coating liquid nozzle 40, which serves as a coating liquid supply unit for supplying coating liquid to the wafer W. The first support arm 31 is supported by Figure 2 The nozzle drive unit 41 shown is movable on the guide rail 30. Thus, the coating liquid nozzle 40 can be moved from a standby portion 42 provided on the outer side of the cup-shaped body 22 on the positive side in the Y direction to above the center of the wafer W within the cup-shaped body 22, and can also be moved on the surface of the wafer W in the radial direction of the wafer W. Furthermore, the first support arm 31 can be raised and lowered by the nozzle drive unit 41, so that the height of the coating liquid nozzle 40 can be adjusted.

[0047] like Figure 1 As shown, the coating liquid nozzle 40 is connected to a supply pipe 43 that supplies the coating liquid to the coating liquid nozzle 40. The supply pipe 43 is connected to a coating liquid supply source 44 that stores the coating liquid. Furthermore, the supply pipe 43 is provided with a supply device group 45 including a valve, a flow rate adjustment unit, and the like that controls the flow of the coating liquid.

[0048] like Figure 1 and Figure 2 As shown, the second support arm 32 supports a first solvent nozzle 50, which serves as a solvent supply unit (first solvent supply unit) for supplying a solvent such as a thinner for the coating liquid. Figure 2 The nozzle drive unit 51 shown is movable on the guide rail 30, enabling the first solvent nozzle 50 to be moved from a standby portion 52 provided on the outer side of the cup-shaped body 22 on the negative Y-direction side to a position above the center of the wafer W within the cup-shaped body 22, and to be moved radially over the surface of the wafer W. Furthermore, the nozzle drive unit 51 enables the second support arm 32 to be raised and lowered, thereby adjusting the height of the first solvent nozzle 50. In this embodiment, the guide rail 30, the second support arm 32, and the nozzle drive unit 51 constitute the moving mechanism of the present invention.

[0049] like Figure 1As shown, the first solvent nozzle 50 is connected to a supply pipe 53 that supplies solvent to the first solvent nozzle 50. The supply pipe 53 is connected to a solvent supply source 54 that stores solvent. In addition, the supply pipe 53 is provided with a supply device group 55 including a valve, a flow rate adjustment unit, etc. that controls the flow of the solvent.

[0050] In this embodiment, the first support arm 31 supporting the coating liquid nozzle 40 and the second support arm 32 supporting the first solvent nozzle 50 are mounted on the same guide rail 30, but they may be mounted on different guide rails. Furthermore, the coating liquid nozzle 40 and the first solvent nozzle 50 may be supported by different support arms 31 and 32, respectively, or they may be supported by the same support arm.

[0051] like Figure 1 As shown, a second solvent nozzle 60 is provided below the spin chuck 20. This second solvent nozzle 60 serves as another solvent supply unit (second solvent supply unit) for supplying a solvent such as a diluent for the coating liquid. The second solvent nozzle 60 is provided at, for example, two locations relative to the wafer W held on the spin chuck 20.

[0052] The second solvent nozzle 60 is connected to a supply pipe 61 that supplies solvent to the second solvent nozzle 60. The supply pipe 61 is connected to a solvent supply source 62 that stores solvent. Furthermore, the supply pipe 61 is provided with a supply device assembly 63 that includes a valve, a flow rate regulator, and other components for controlling the flow of the coating liquid. While the solvent supply source 54 and the solvent supply source 62 are separate components in this embodiment, a shared solvent supply source may also be used.

[0053] In the above coating treatment device 1, as Figure 1 As shown, a control unit 100 is provided. The control unit 100 is, for example, a computer having a CPU and memory, and includes a program storage unit (not shown). The program storage unit stores a program for controlling the processing of wafers W in the coating processing apparatus 1. Furthermore, the program storage unit also stores a program for controlling the operation of the coating processing apparatus 1 to implement the coating processing in the coating processing apparatus 1, which will be described later. The above-mentioned program is stored in a computer-readable storage medium H and can be installed from the storage medium H into the control unit 100.

[0054] <Operation of Coating Treatment Device 1>

[0055] Next, the coating process performed in the coating processing apparatus 1 configured as described above will be described. In the coating process of this embodiment, a coating film having a high film thickness of, for example, approximately 20 μm to 80 μm is formed on a wafer W. Figure 3 The state of the liquid film on the wafer W in each step of the coating process is schematically shown.

[0056] The wafer W introduced into the coating processing apparatus 1 is first held by the spin chuck 20 under suction. Next, the coating liquid nozzle 40 in the standby section 42 is moved by the first support arm 31 to a position above the center of the wafer W. At this time, the first solvent nozzle 50 is on standby in the standby section 52.

[0057] Then, if Figure 3 As shown in (a), while the wafer W is being rotated, the coating liquid L is supplied from the coating liquid nozzle 40 to the center of the wafer W. In this way, the coating liquid L is spread on the wafer W by the centrifugal force generated by the rotation of the wafer W. Figure 3 As shown in FIG. 5 ( b ), a coating film F is formed on the surface of the wafer W. When the supply of the coating liquid L is completed, the coating liquid nozzle 40 moves to the standby portion 42 .

[0058] Here, when using a coating liquid L having a high viscosity, the coating liquid L has difficulty flowing on the surface of the wafer W, and a convex protrusion (hereinafter referred to as a hump H) that appears annular when viewed from above is formed on the peripheral edge of the surface of the wafer W, thereby thickening the coating film F. In particular, when forming a thick coating film F, the hump H increases as the amount of coating liquid L supplied increases. Therefore, in order to uniformly form the coating film F on the wafer surface and remove the hump H, a solvent for the coating liquid L (coating film F) is supplied to the hump H.

[0059] Specifically, the first solvent nozzle 50 of the standby unit 52 is moved to above the peripheral edge of the wafer W by the second support arm 32. Figure 3 As shown in (c), the solvent S1 is supplied from the first solvent nozzle 50, that is, from the front side of the wafer W, to the hump H. At this time, the solvent S2 may be supplied from the second solvent nozzle 60, that is, from the back side of the wafer W, to the hump H. Figure 3 As shown in (d), the hump H is dissolved and removed by solvent S1 (solvent S2). The removal process of the hump H will be described in detail later.

[0060] In this way, a coating film F having a uniform film thickness is formed on the wafer surface, and a series of coating processes in the coating processing apparatus 1 is completed.

[0061] <Removal of Hump H>

[0062] Next, the removal process of the hump H on the peripheral edge of the wafer W will be described. In this embodiment, for example, when the radius of the wafer W is 150 mm, the peripheral edge is a circular ring extending from the center of the wafer W outside the radius of 140 mm.

[0063] (Existing method)

[0064] When a coating film F having a high film thickness is formed using a high-viscosity coating liquid L as in this embodiment, the hump H becomes large. Therefore, as in the coating treatment method described in the conventional patent document 1, it is difficult to completely remove the hump H by only performing the step of supplying a solvent to the hump H (hereinafter sometimes referred to as the solvent supply step) and the step of rotating the wafer W for a short time and at a high speed (hereinafter sometimes referred to as the short rotation step). Figure 4 This point will be explained. Figure 4 FIG. 1 shows the state of the liquid film on the peripheral portion of the surface of the wafer W when a conventional coating treatment method is performed.

[0065] like Figure 4 When the coating process is performed as shown in (a), a hump H of the coating film F is formed on the peripheral portion of the surface of the wafer W. Figure 4 As shown in (b), while the wafer W is rotated, the solvent S is supplied from the first solvent nozzle 50 to the hump H. The solvent S is supplied over the entire circumference of the hump H. As a result, a portion of the hump H is dissolved by the solvent S. Hereinafter, the portion dissolved in the hump H is referred to as residue M. Thereafter, when the wafer W is rotated for a short time (for example, 0.5 seconds) and at a high speed (for example, 1050 rpm), as shown in FIG. Figure 4 The solvent S and the residue M remaining on the surface of the coating film F shown in (c) are discharged from the surface of the coating film F due to the centrifugal force.

[0066] However, as described above, only the solvent supply step and the short rotation step are performed. Figure 4 As shown in (c), the hump H becomes smaller, but the hump H still remains. Figure 4 The original hump H shown in (a) is large, so it cannot be completely removed by supplying the solvent S only once. Figure 4 As shown in (c), the residue M on the outside of the hump H is discharged from the surface of the coating film F, but the residue M on the inside of the hump H flows to the outside (see Figure 4 (c)), it remains on the surface of the coating film F and forms a hump H again. Therefore, during the solvent supply step and the short rotation step, the top position of the hump H moves radially outward and remains on the surface peripheral portion of the wafer W.

[0067] (First embodiment)

[0068] Then, the inventors have conducted in-depth research and have come up with the idea of repeatedly performing the solvent supply step and the short rotation step. In the following description, a continuous process of the solvent supply step and the short rotation step is referred to as a loop process, and the number of repetitions of the loop process is referred to as the number of cycles. Figure 5 1 and 2 show the state of the liquid film on the peripheral portion of the surface of the wafer W when the coating treatment method according to the first embodiment is performed.

[0069] like Figure 5 When the coating process is performed as shown in (a), a hump H of the coating film F is formed on the peripheral edge of the surface of the wafer W. When the coating process is completed, the first solvent nozzle 50 is moved to a position 1 mm from the outer edge of the wafer W and arranged.

[0070] Then, if Figure 5 As shown in (b), while the wafer W is rotating, the solvent S is supplied from the first solvent nozzle 50 to the hump H. The solvent S is supplied over the entire circumference of the hump H. At this time, the solvent S is supplied at a position, for example, 7 mm from the outer edge of the wafer W. During the solvent supply step, the first solvent nozzle 50 moves to the solvent S supply position. Furthermore, the solvent S supply time is, for example, 10 seconds, and the rotation speed of the wafer W is, for example, 200 rpm. As a result, a portion of the hump H is dissolved by the solvent S.

[0071] Furthermore, the rotation speed of the wafer W during the solvent supply step is preferably 500 rpm or less, and the supply time of the solvent S is preferably 10 seconds or less. The target film thickness of the coating film F is a high film thickness, so the rotation speed of the wafer W and the supply time of the solvent S can be reduced to prevent excessive dissolution of the solvent S.

[0072] Then, the supply of solvent S is stopped and the rotation of wafer W is accelerated. Thus, wafer W is rotated for a short time and at a high speed. At this time, the rotation time of wafer W is, for example, 0.5 seconds and the rotation speed is, for example, 2000 rpm. Figure 5 As shown in (c), the solvent S and residue M remaining on the surface of the coating film F are expelled from the surface of the coating film F due to centrifugal force. Consequently, the peak position of the hump H moves radially outward and becomes smaller. Furthermore, during the short rotation step, the first solvent nozzle 50 returns to a position, for example, 1 mm from the original outer edge of the wafer W.

[0073] Furthermore, the rotation speed of the wafer W during the short rotation step is preferably 2000 rpm or less. For example, if the wafer W is rotated at a high speed exceeding 2000 rpm, the residue M is easily transferred, and the remaining hump H becomes larger. Furthermore, when the wafer W is rotated at a high speed, bubbles are easily generated in the coating film F. Therefore, in this embodiment, the rotation speed of the wafer W is set to 2000 rpm.

[0074] like Figure 4 As shown, in the conventional coating method, the solvent supply step and the short rotation step are completed at once, but in this embodiment, the solvent supply step and the short rotation step are repeated. Figure 5 The solvent supply step shown in (d) and Figure 5The solvent supply step and the short rotation step in each circulation process are respectively the same as those in the embodiment of the present invention. Figure 5 (b) and Figure 5 The method described in (c) is the same.

[0075] Furthermore, during the circulation process, that is, from the end of the short rotation step until the next solvent supply step, the rotation speed of the wafer W is preferably kept at 500 rpm or less while the wafer W continues to rotate. Rotating the wafer W at high speed during the circulation process may reduce the overall thickness of the coating film F.

[0076] So, if Figure 5 (d) and Figure 5 When the cycle process is repeated as shown in (e), the top position of the hump H moves radially downward and outward in each cycle, and the hump H is gradually removed. As a result, as shown in FIG. Figure 5 As shown in (f), it is possible to flatten the peripheral edge of the coating film F. Therefore, according to this embodiment, it is possible to form a coating film F having a uniform film thickness on the surface of the wafer W.

[0077] In addition, Figure 4 In the conventional coating method shown above, when the supply timing and radial supply position of the solvent S are varied, the film thickness of the coating film F at the peripheral edge portion changes in a complex manner, making it difficult to predict this behavior and requiring repeated trial and error to set the supply timing and supply position of the organic solvent. Therefore, setting conditions to optimize the supply timing and supply position of the solvent S is difficult.

[0078] In this regard, in the method of repeatedly performing the cycle treatment as in the present embodiment, the parameters when setting the conditions can be minimized, which can simplify the optimization of the processing conditions. Specifically, the parameters when setting the conditions are the number of cycles, the supply time of the solvent S, and the radial supply position of the solvent S. Figures 6 to 8 These are graphs showing changes in the film thickness of the coating film F on the peripheral portion of the surface of the wafer W when the number of cycles, the supply time of the solvent S, and the supply position of the solvent S are changed. Figures 6 to 8 In FIG. 1 , the horizontal axis represents the radial position of the wafer W, and the vertical axis represents the film thickness of the coating film F. In this embodiment, the radius of the wafer W is 150 mm, and the position of 150 mm on the horizontal axis represents the outer edge of the wafer W.

[0079] like Figure 7 As shown in FIG. 1 , the supply time of the solvent S is varied to 4 seconds, 5 seconds, 6 seconds, and 7 seconds, while the number of cycles is fixed at 5 and the supply position of the solvent S is fixed at a position 7 mm from the outer edge of the wafer W. In this case, as the supply time of the solvent S is increased, the thickness of the coating film F radially outward of the supply position of the solvent S decreases.

[0080] like Figure 8 As shown in FIG. 1 , under the conditions that the number of cycles is fixed at 4 and the solvent supply time is fixed at 4 seconds, the supply position of the solvent S is changed to 5 mm, 7 mm, and 9 mm from the outer edge of the wafer W. In this case, as the supply position of the solvent S is moved radially inward, the top position of the hump H also moves radially inward.

[0081] When the supply timing or supply position of the solvent S is changed as described above, the film thickness of the coating film F at the peripheral portion changes in a complex manner.

[0082] On the other hand, Figure 6 As shown in FIG. 1 , the supply time of solvent S is fixed at 4 seconds, and the supply position of solvent S is fixed at a position 7 mm from the outer edge of wafer W. The number of cycles is varied to 4, 5, and 6. In this case, as the number of cycles increases, the overall thickness of the coating film F at the peripheral edge decreases. In other words, the coating film F does not change locally, as when the supply time or supply position of solvent S is changed, but by controlling the number of cycles, the overall thickness of the coating film F at the peripheral edge can be changed.

[0083] As described above, by controlling the number of cycles according to the supply timing and supply position of the solvent S, the coating film F in the peripheral portion can be changed as a whole to remove the hump H. As described above, in this embodiment, the setting conditions can be easily optimized.

[0084] Next, another embodiment of the hump H removal process will be described. While the first embodiment described above repeatedly performs a loop process, the second to fourth embodiments perform different processes in addition to the repeated loop process. The following description will focus on the differences from the first embodiment.

[0085] (Second embodiment)

[0086] The second embodiment will be described. Figure 9 1 shows the state of the liquid film on the surface peripheral portion of the wafer W when the coating treatment method according to the second embodiment is performed. In the first embodiment, during the solvent supply step in the circulation treatment, the solvent S is supplied from the front side of the wafer W to the hump H. However, in the second embodiment, the solvent S is supplied from both the front side and the back side of the wafer W to the hump H.

[0087] like Figure 9As shown in (b), while the wafer W is rotated, the solvent S1 is supplied to the hump H from the first solvent nozzle 50 on the front side of the wafer W, and the solvent S2 is supplied to the hump H from the second solvent nozzle 60 on the back side of the wafer W. At this time, the supply time of the solvent S1 and the solvent S2 are both 10 seconds, for example, and the rotation speed of the wafer W is, for example, 200 rpm. The solvent S1 from the first solvent nozzle 50 dissolves the upper part of the hump H. Figure 9 In (b), the portion dissolved by the solvent S1 is shown as a residue M1. The solvent S2 from the second solvent nozzle 60 flows from the back side of the wafer W along the outer side to the front side, dissolving the lower portion of the hump H. In particular, in the solvent supply step, the wafer W is rotated at a low speed, so that the solvent S2 from the back side easily flows around the hump H on the front side. Figure 9 In (b), the portion dissolved by the solvent S2 is shown as the residue M2.

[0088] Then, the supply of solvent S1 and solvent S2 is stopped, and the wafer W is rotated for a short time and at a high speed. At this time, the rotation time of the wafer W is, for example, 0.5 seconds, and the rotation speed is, for example, 2000 rpm. Figure 9 As shown in (c), the solvents S1 and S2 and the residues M1 and M2 remaining on the surface of the coating film F are discharged from the surface of the coating film F by the centrifugal force. Then, the top position of the hump H moves radially outward and becomes smaller.

[0089] Then, repeat Figure 9 The solvent supply step shown in (d) and Figure 9 The solvent supply step and the short rotation step in each circulation process are respectively the same as those in the embodiment of the present invention. Figure 9 (b) and Figure 9 Then, when the cycle process is repeated, the top position of the hump H moves radially outward in each cycle process, and the hump H is gradually removed. As a result, Figure 9 As shown in (f), the peripheral portion of the coating film F can be flattened.

[0090] In this embodiment, a coating film F having a uniform thickness can also be formed on the surface of the wafer W. Furthermore, during the solvent supply step in each cycle, solvents S1 and S2 are supplied to the hump H from both the front and back sides of the wafer W, further improving the solubility of the hump H. In particular, during the solvent supply step, the wafer W is rotated at a low speed, and the supply time of solvents S1 and S2 is short. Therefore, the solvents S1 and S2 have a greater effect in improving the solubility of the hump H. Furthermore, the increased solubility of the hump H increases the fluidity of the residues M1 and M2, making it easier to remove the residues M1 and M2 during the short rotation step. Consequently, the flatness of the coating film F can be further improved.

[0091] Furthermore, in this embodiment, solvent S1 and solvent S2 are supplied simultaneously to hump H. However, the timing of these supplies may be different. For example, solvent S1 may be supplied to hump H from first solvent nozzle 50, followed by solvent S2 supplied to hump H from second solvent nozzle 60. In this case, hump H can be dissolved by both solvent S1 and solvent S2. However, by supplying solvent S1 and solvent S2 simultaneously, the solubility of hump H increases.

[0092] In the present embodiment, the position at which the solvent S1 is supplied from the first solvent nozzle 50 and the position at which the solvent S2 is supplied from the second solvent nozzle 60 may be shifted in the circumferential direction.

[0093] (Third embodiment)

[0094] A third embodiment will be described. Figure 10 The figure shows the state of the liquid film on the peripheral portion of the surface of the wafer W when the coating method according to the third embodiment is performed. In the third embodiment, when the circulation process is repeated, the supply position of the solvent S in each solvent supply step is moved from the radial inside to the outside.

[0095] like Figure 10 As shown in (a), after the coating process, a hump H is wide and extends radially inward on the outer peripheral portion of the surface of the wafer W. The shape and position of the hump H are determined by the type of the coating liquid L.

[0096] When the coating process is completed, the first solvent nozzle 50 is disposed at a position, for example, 1 mm from the outer edge of the wafer W. Hereinafter, the position of the first solvent nozzle 50 is referred to as an origin position P0.

[0097] Afterwards, if Figure 10 As shown in (b) of FIG. , while the wafer W is rotated, solvent S is supplied from the first solvent nozzle 50 to the hump H. At this time, the supply position P1 of the solvent S is, for example, 7 mm from the outer edge of the wafer W. Specifically, in this solvent supply step, the first solvent nozzle 50 moves from the origin position P0 to the supply position P1, and then returns from the supply position P1 to the origin position P0. Furthermore, during this movement from the origin position P0 to the supply position P1 to the origin position P0, solvent S is supplied from the first solvent nozzle 50.

[0098] Furthermore, in the solvent supply step of this embodiment, the solvent S is supplied even while the first solvent nozzle 50 is moving. However, the solvent S may be supplied only when the first solvent nozzle 50 is stopped at the supply position P1. However, when the solvent S is supplied while the first solvent nozzle 50 is stopped at the supply position P1, the hump H may be significantly affected, causing the solvent S to scatter (splash). Therefore, by supplying the solvent S even while the first solvent nozzle 50 is moving from the radially outer side to the radially inner side, such splashing can be reliably prevented.

[0099] After that, the supply of solvent S is stopped and the wafer W is rotated for a short time at a high speed. Figure 10 As shown in (c), the solvent S and residue M remaining on the surface of the coating film F are expelled from the surface of the coating film F due to centrifugal force. As a result, the peak position of the hump H moves radially outward and becomes smaller. Furthermore, during the short rotation step, the first solvent nozzle 50 returns to its origin position P0.

[0100] Furthermore, in this embodiment, Figure 10 The solvent supply step shown in (b) and Figure 10 The cyclic treatment of the short rotation step shown in (c) was repeated twice.

[0101] Then, proceed Figure 10 The solvent supply step (d) is shown in FIG. At this time, the supply position P2 of the solvent S is positioned outside the supply position P1, for example, 5 mm from the outer edge of the wafer W. Furthermore, during this solvent supply step, the first solvent nozzle 50 moves from the origin position P0 to the supply position P2 and then returns from the supply position P2 to the origin position P0. Furthermore, during this movement from the origin position P0 to the supply position P2 to the origin position P0, the solvent S is supplied from the first solvent nozzle 50.

[0102] Afterwards, proceed Figure 10 The short rotation step shown in (e) is shown in FIG. Figure 10 The solvent supply step shown in (d) and Figure 10 The cycle treatment of the short rotation step shown in (e) was repeated three times.

[0103] In this embodiment, as described above, the supply position of the solvent S is moved from the radially inner side (supply position P1) to the radially outer side (supply position P2). Figure 10 The width of the hump H shown in (a) is wide and extends radially inward. The inner portion of the hump H is removed first, and then the entire hump H is uniformly removed. In other words, the hump H can be appropriately removed by adjusting the supply position of the solvent S according to the shape of the hump H after the coating process.

[0104] Furthermore, when the circulation process is repeated, the top position of the hump H moves radially outward. In this regard, the solvent S can be reliably supplied to the hump H by moving the supply position of the solvent S from radially inside to outside.

[0105] Moreover, the results are as follows Figure 10 As shown in (f), it is possible to flatten the peripheral edge of the coating film F. Therefore, according to this embodiment, it is possible to form a coating film F having a uniform film thickness on the surface of the wafer W.

[0106] (Fourth embodiment)

[0107] A fourth embodiment will be described. Figure 11 1 shows the state of the liquid film on the surface peripheral portion of the wafer W when the coating treatment method according to the fourth embodiment is performed. In the third embodiment, the supply position of the solvent S is moved from the radial inner side to the radial outer side in each solvent supply step. However, in the fourth embodiment, the supply position of the solvent S can be moved from the radial outer side to the radial inner side in each solvent supply step.

[0108] like Figure 11 As shown in (a), after the coating process is performed, the hump H on the outer peripheral portion of the surface of the wafer W is narrow and exists only on the radially outer side.

[0109] Then, if Figure 11 As shown in (b), while the wafer W is rotated, the solvent S is supplied from the first solvent nozzle 50 to the hump H. At this time, the supply position P3 of the solvent S is, for example, a position 3 mm from the outer edge of the wafer W. The first solvent nozzle 50 moves from the origin position P0 to the supply position P3, and then from the supply position P3 to the origin position P0, supplying the solvent S during the movement.

[0110] After that, the supply of solvent S is stopped and the wafer W is rotated for a short time at a high speed. Figure 11 As shown in (c), the solvent S and residue M remaining on the surface of the coating film F are discharged from the surface of the coating film F due to centrifugal force. Furthermore, the peak position of the hump H moves radially outward and becomes smaller. Furthermore, during the short rotation step, the first solvent nozzle 50 returns to the origin position P0.

[0111] Furthermore, in this embodiment, Figure 11 The solvent supply step shown in (b) and Figure 11 The cyclic treatment of the short rotation step shown in (c) was repeated twice.

[0112] Afterwards, proceed Figure 11The solvent supply step (d) is shown in FIG. At this time, the supply position P4 of the solvent S is set to be located inside the supply position P3, for example, 7 mm from the outer edge of the wafer W. In addition, in this solvent supply step, the first solvent nozzle 50 moves from the origin position P0 to the supply position P4, and then from the supply position P4 to the origin position P0, supplying the solvent S during the movement.

[0113] Afterwards, proceed Figure 10 The short rotation step shown in (e) is shown in FIG. Figure 10 The solvent supply step shown in (d) and Figure 10 The cyclic treatment of the short rotation step shown in (e) was repeated three times.

[0114] In this embodiment, the supply position of the solvent S is moved from the radially inner side (supply position P3) to the radially outer side (supply position P4) as described above. Figure 11 The narrow hump H shown in (a) is only located on the radially outer side. The outer portion of the hump H is removed first, and then the entire hump H is uniformly removed. In other words, the hump H can be appropriately removed by adjusting the supply position of the solvent S according to the shape of the hump H after the coating process.

[0115] Moreover, the result is Figure 11 As shown in (f), it is possible to flatten the peripheral edge of the coating film F. Therefore, according to this embodiment, it is possible to form a coating film F having a uniform film thickness on the surface of the wafer W.

[0116] The embodiments disclosed herein are illustrative in all respects and should not be construed as limiting. The embodiments described above may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims.

[0117] While the above embodiments illustrate an example of forming a protective film on the surface of a wafer, the present invention is also applicable to coating processes in which a resist film is formed by applying another coating liquid, such as a resist liquid, to the surface of the wafer. Furthermore, while the above embodiments illustrate an example of coating a wafer, the present invention is also applicable to substrates other than wafers, such as FPDs (flat panel displays) and photomask reticles.

[0118] In addition, the following configurations also belong to the technical scope of the present invention.

[0119] (1) A substrate processing method for processing a substrate, comprising:

[0120] (a) a step of applying a coating liquid on the surface of a substrate by spin coating to form a coating film;

[0121] (b) a step of supplying the solvent of the coating liquid to the convex portion of the coating film formed on the peripheral portion of the surface of the substrate in the step (a); and

[0122] (c) rotating the substrate while stopping the supply of the solvent so as to move the apex of the protrusion outward in the radial direction of the substrate,

[0123] Repeat the above steps (b) and (c).

[0124] According to the above (1), when the process of steps (b) and (c) is repeated continuously, the apex position of the protrusion moves radially outward in each cycle, and the protrusion is gradually removed. As a result, the peripheral edge of the coating film can be flattened, and a coating film F with a uniform film thickness can be formed on the surface of the substrate. In addition, when the process cycle is repeated as described above, the parameters for setting the conditions can be minimized, making it easier to optimize the processing conditions.

[0125] (2) In the substrate processing method described in (1) above,

[0126] In the step (b), the solvent is supplied to the protrusions from the front side of the substrate, and the solvent is supplied to the protrusions from the back side of the substrate.

[0127] According to (2) above, since the solvent is supplied to the protrusions from both the front and back sides of the substrate, the solubility of the protrusions can be further improved. Furthermore, the increased solubility of the protrusions increases the fluidity of the residue formed by dissolving the protrusions, making it easier to remove the residue in step (c). Consequently, the flatness of the coating film can be further improved.

[0128] (3) In the substrate processing method described in (2) above,

[0129] In the above step (b), the above solvent is supplied from both the front side and the back side of the substrate.

[0130] (4) In the substrate processing method described in any one of (1) to (3),

[0131] When the steps (b) and (c) are repeated, the supply position of the solvent in the step (b) is moved in the radial direction of the substrate.

[0132] According to the above (4), the supply position of the solvent in step (b) is moved in the radial direction of the substrate according to the shape of the protrusion, so that the protrusion can be appropriately removed.

[0133] (5) In the substrate processing method described in (4) above,

[0134] The supply position of the solvent in the step (b) is moved from the inner side to the outer side in the radial direction of the substrate.

[0135] (6) In the substrate processing method described in (4) above,

[0136] The supply position of the solvent in the step (b) is moved from the outer side to the inner side in the radial direction of the substrate.

[0137] (7) In the substrate processing method described in any one of (1) to (6),

[0138] The thickness of the coating film is controlled by controlling the number of repetitions of the steps (b) and (c) according to the supply timing and supply position of the solvent in the step (b).

[0139] (8) In the substrate processing method described in any one of (1) to (7),

[0140] The solvent is supplied in the step (b) while the substrate is rotated.

[0141] The rotation speed of the substrate in the above step (c) is greater than the rotation speed of the substrate in the above step (b),

[0142] The rotation speed of the substrate in the above step (c) is 2000 rpm or less.

[0143] (9) In the substrate processing method described in any one of (1) to (8),

[0144] The viscosity of the coating liquid is 1000 cp to 10000 cp.

[0145] (10) A substrate processing device for applying a coating liquid to a substrate, comprising:

[0146] a substrate holding portion configured to hold and rotate the substrate;

[0147] a coating liquid supply portion configured to apply the coating liquid to the substrate held by the substrate holding portion;

[0148] a solvent supply portion configured to supply the solvent of the coating liquid to the peripheral edge portion of the substrate held by the substrate holding portion from the front side of the substrate;

[0149] and control department,

[0150] The control unit is configured to include:

[0151] (a) a step of applying a coating liquid on the surface of a substrate by spin coating to form a coating film;

[0152] (b) a step of supplying the solvent of the coating liquid to the convex portion of the coating film formed on the peripheral portion of the surface of the substrate in the step (a); and

[0153] (c) rotating the substrate while stopping the supply of the solvent so as to move the apex of the protrusion outward in the radial direction of the substrate,

[0154] The control unit controls the substrate holding unit, the coating liquid supply unit, and the solvent supply unit to repeatedly perform the steps (b) and (c).

[0155] (11) In the substrate processing apparatus described in (10) above,

[0156] The system further includes another solvent supplying member configured to supply the solvent to the peripheral edge of the substrate held by the substrate holding portion from the back side of the substrate,

[0157] The control unit is configured to control the solvent supply unit and the other solvent supply unit so that in the step (b), the solvent is supplied to the convex portion from the front side of the substrate and the solvent is supplied to the convex portion from the back side of the substrate.

[0158] (12) In the substrate processing apparatus described in (10) or (11) above,

[0159] The device further includes a moving mechanism configured to move the solvent supply portion in a horizontal direction.

[0160] The control unit is configured to control the solvent supply unit and the moving mechanism so that when the steps (b) and (c) are repeated, the supply position of the solvent in the step (b) is moved in the radial direction of the substrate.

Claims

1. A substrate processing method for processing a substrate, characterized in that: include: (a) a step of applying a coating liquid on the surface of a substrate by spin coating to form a coating film; (b) a step of supplying the solvent of the coating liquid to the convex portion of the coating film formed on the peripheral portion of the surface of the substrate in the step (a); and (c) rotating the substrate while stopping the supply of the solvent so as to move the apex of the protrusion outward in the radial direction of the substrate, Repeat the cycle of step (b) and step (c). By repeating the cycle process, the apex position of the convex portion moves radially outward in each cycle process, and the convex portion is gradually removed. When the circulation process is repeated, the supply position of the solvent in the step (b) is moved in the radial direction of the substrate according to the shape of the protrusion.

2. The substrate processing method according to claim 1, wherein: In the step (b), the solvent is supplied to the protrusions from the front side of the substrate, and the solvent is supplied to the protrusions from the back side of the substrate.

3. The substrate processing method according to claim 2, wherein: In the step (b), the solvent is supplied from both the front side and the back side of the substrate.

4. The substrate processing method according to claim 1, wherein: The supply position of the solvent in the step (b) is moved from the inner side to the outer side in the radial direction of the substrate.

5. The substrate processing method according to claim 1, wherein: The supply position of the solvent in the step (b) is moved from the outer side to the inner side in the radial direction of the substrate.

6. The substrate processing method according to claim 1 or 2, wherein: The thickness of the coating film is controlled by controlling the number of repetitions of the steps (b) and (c) according to the supply timing and supply position of the solvent in the step (b).

7. The substrate processing method according to claim 1 or 2, wherein: The solvent is supplied in the step (b) while the substrate is rotated. The rotation speed of the substrate in step (c) is greater than the rotation speed of the substrate in step (b), The rotation speed of the substrate in the step (c) is below 2000 rpm.

8. The substrate processing method according to claim 1 or 2, wherein: The coating liquid has a viscosity of 1000 cp to 10000 cp.

9. A substrate processing device for applying a coating liquid to a substrate, characterized in that: include: a substrate holding portion configured to hold and rotate the substrate; a coating liquid supply portion configured to apply the coating liquid to the substrate held by the substrate holding portion; a solvent supply portion configured to supply the solvent of the coating liquid to the peripheral edge portion of the substrate held by the substrate holding portion from the front side of the substrate; a moving mechanism configured to move the solvent supply portion in a horizontal direction; and Control Department, The control unit includes: (a) a step of applying a coating liquid on the surface of a substrate by spin coating to form a coating film; (b) a step of supplying the solvent of the coating liquid to the convex portion of the coating film formed on the peripheral portion of the surface of the substrate in the step (a); and (c) rotating the substrate while stopping the supply of the solvent so as to move the apex of the protrusion outward in the radial direction of the substrate, The control unit controls the substrate holding unit, the coating liquid supply unit and the solvent supply unit so that the cycle processing of step (b) and step (c) is repeatedly performed, and the apex position of the protrusion moves radially outward in each cycle processing, and the protrusion is gradually removed. When the cycle processing is repeated, the supply position of the solvent in step (b) is moved radially of the substrate according to the shape of the protrusion.

10. The substrate processing device according to claim 9, wherein: The system further includes another solvent supplying member configured to supply the solvent to the peripheral edge of the substrate held by the substrate holding portion from the back side of the substrate, The control unit is configured to control the solvent supply unit and the other solvent supply unit so that in the step (b), the solvent is supplied to the protrusion from the front side of the substrate and the solvent is supplied to the protrusion from the back side of the substrate.

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