Liquid treatment method and liquid treatment device

Abstract

This invention provides a liquid treatment method and a liquid treatment apparatus capable of suppressing the formation of lint-like clumps caused by coating liquid splashed from a substrate. The liquid treatment method includes: a step of supplying a coating liquid to the front side of a substrate; and a step of diffusing the coating liquid on the front side of the substrate to form a coating film on the front side, wherein in the step of forming the coating film, solvent of the coating liquid is continuously supplied from a solvent supply unit to the peripheral portion of the front side of the substrate before the coating liquid reaches the peripheral portion of the front side of the substrate, and this supply continues at least until the step of forming the coating film ends.

Description

Technical Field

[0001] This invention relates to liquid treatment methods and liquid treatment apparatus. Background Technology

[0002] The substrate processing apparatus of Patent Document 1 has a circular cup-shaped substrate positioned below a rotating holding part, and an annular middle cup-shaped part mounted on the cup-shaped substrate. A through hole is formed in the center of the cup-shaped substrate, through which the rotating shaft of the motor is disposed, and the rotating holding part is mounted at its front end. A plurality of vent holes are formed along the through hole in the cup-shaped substrate. The vent holes are positioned at a location corresponding to the inner side of the outer periphery of the rotating holding part. When the substrate held by the rotating holding part rotates at high speed, air is supplied to the back side of the substrate through the vent holes to prevent the space on the back side of the substrate from becoming negative pressure, thereby preventing mist from spreading to the back side of the substrate.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 11-283899 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] The technology of this invention can suppress the formation of cotton-like clumps caused by coating liquid falling off the substrate.

[0008] Technical solutions for solving technical problems

[0009] One aspect of the present invention includes: a step of supplying a coating liquid to the front side of a substrate; and a step of diffusing the coating liquid on the front side of the substrate to form a coating film on the front side, wherein, in the step of forming the coating film, solvent of the coating liquid is continuously supplied from a solvent supply unit to the peripheral portion of the front side of the substrate before the coating liquid reaches the peripheral portion of the front side of the substrate, and this supply continues at least until the step of forming the coating film ends.

[0010] Invention Effects

[0011] According to the present invention, the formation of cotton-like clumps caused by coating liquid falling off the substrate can be suppressed. Attached Figure Description

[0012] Figure 1 This is a schematic diagram illustrating the filamentous portions formed by the coating liquid that is splattered from the substrate.

[0013] Figure 2 This is a longitudinal cross-sectional view showing the general structure of the resist coating apparatus of the liquid treatment apparatus in this embodiment.

[0014] Figure 3 This is a cross-sectional view showing the outline structure of the resist coating apparatus of the liquid treatment apparatus in this embodiment.

[0015] Figure 4 This is a flowchart illustrating an example of a wafer processing procedure in a resist coating apparatus.

[0016] Figure 5 This is a diagram that roughly illustrates the state of the wafer W during the various steps involved in wafer processing.

[0017] Figure 6 This is a diagram showing an example of the position of the solvent supply nozzle when organic solvent is continuously supplied.

[0018] Figure 7 This is a graph that confirms the results of test 1.

[0019] Figure 8 This is a graph that confirms the results of test 3.

[0020] Explanation of reference numerals in the attached figures

[0021] 1. Resist Coating Device

[0022] 20 Rotary retaining part

[0023] 43 Corrosion resist liquid supply nozzle

[0024] 46 Solvent supply nozzle

[0025] 100 Control Department

[0026] B. Edge Sloping Section

[0027] W chip

[0028] We Periphery Department

[0029] Ws (Front) Detailed Implementation

[0030] In the manufacturing process of semiconductor devices, a coating process is performed to form a coating film by applying a coating liquid such as a photoresist solution onto a substrate such as a semiconductor wafer (hereinafter referred to as a "wafer").

[0031] In the aforementioned coating process, a coating liquid is supplied to the surface (front side) of a rotating wafer, and centrifugal force is used to spread the coating liquid across the wafer surface, thus coating the entire front surface of the wafer. This so-called spin coating method is widely used. In liquid treatment apparatuses that use spin coating, a container called a cup-shaped body is provided to prevent the coating liquid that splatters from the surface of the rotating wafer from spreading to the surrounding area. Furthermore, exhaust is performed from the bottom of the cup-shaped body for the purpose of creating a desired airflow on the surface of the coating film.

[0032] However, in recent years, there has been a demand for forming thicker coatings on the surface of wafers. When forming thicker coatings, for example, high-viscosity coating solutions are used. Regarding high-viscosity coating solutions, during spin coating, a portion of the coating solution supplied to the wafer surface is thrown off from the wafer's periphery. In this case, such as... Figure 1 As shown, filamentous portions H are formed extending radially outward from the periphery of the wafer W's surface. These filamentous portions H further extend during the rotation of the wafer W and then dry and solidify. The solidified filamentous portions H intertwine with each other, forming cotton-like clumps. These cotton-like clumps, for example, break off from the wafer W during processing, becoming a major cause of adverse conditions such as blocking the exhaust path within the cup-shaped body of the liquid processing apparatus and hindering exhaust. When exhaust from the cup-shaped body of the liquid processing apparatus is obstructed and the exhaust pressure rises, for example, the desired airflow cannot be formed on the surface of the coating film on the wafer, and a uniform in-plane film thickness distribution cannot be obtained.

[0033] Therefore, the technology of the present invention suppresses the formation of cotton-like clumps caused by the coating liquid falling from the wafer.

[0034] Hereinafter, the liquid treatment method and liquid treatment apparatus of this embodiment will be described with reference to the accompanying drawings. Furthermore, in this specification and the accompanying drawings, elements having substantially the same functional structure are labeled with the same reference numerals, thereby omitting redundant descriptions.

[0035] (Liquid treatment device)

[0036] Figure 2 and Figure 3 These are longitudinal and cross-sectional views showing the general structure of the resist coating apparatus 1, which is the liquid treatment apparatus of this embodiment.

[0037] Anti-corrosion coating device 1 Figure 2 As shown, the device has a processing container 10 capable of sealing its interior. A feed port (not shown) for a wafer W serving as a substrate is formed on the side of the processing container 10.

[0038] A rotation holding section 20 is provided within the processing container 10 to hold and rotate the wafer W. Specifically, the rotation holding section 20 holds the wafer W and rotates it about a rotation axis perpendicular to the front surface of the wafer W. Furthermore, the rotation holding section 20 includes a rotary chuck 21 rotatably configured to hold the wafer W, and a chuck drive section 22 having an actuator such as a motor to rotate the rotary chuck 21. The rotary chuck 21 is configured to rotate at various speeds (rotational speeds) using the chuck drive section 22. Furthermore, the chuck drive section 22 is provided with a lifting drive mechanism, for example, having an actuator such as a cylinder, and the rotary chuck 21 is configured to be lifted and lowered using the lifting drive mechanism.

[0039] Additionally, a cup-shaped body 30 is provided within the processing container 10. The cup-shaped body 30 includes: an outer cup-shaped body 31, which is disposed on the outside of the rotary chuck 21 in a manner capable of surrounding the wafer W held in the rotary chuck 21; and an inner cup-shaped body 32 located on the inner periphery of the outer cup-shaped body 31. The outer cup-shaped body 31 receives and recovers liquids that spill or fall from the wafer W.

[0040] like Figure 3 As shown, in the negative X direction of the outer cup-shaped body 31 ( Figure 3 The lower side is formed along the Y direction ( Figure 3 The track 40 extends in the left-right direction. For example, the track 40 extends from the negative Y direction of the outer cup-shaped body 31. Figure 3 The outer side of the left side forms to the positive direction of the Y direction. Figure 3 (To the right) on the outer side. Two arms 41 and 42 are provided on track 40.

[0041] A resist supply nozzle 43, serving as a coating liquid supply unit, is supported on the first arm 41. The resist supply nozzle 43 supplies resist liquid, which is used as a coating liquid, to the front of the wafer W held in the rotating chuck 21. The resist liquid released and supplied by the resist supply nozzle 43 has a high viscosity of 100 cp or more. The first arm 41 can move on the track 40 using a moving mechanism for the resist supply nozzle 43, namely a nozzle drive unit 44 equipped with an actuator such as an electric motor. As a result, the resist supply nozzle 43 can be moved from the standby unit 45 located on the outer side of the outer cup-shaped body 31 in the negative Y direction to above the center of the wafer W inside the outer cup-shaped body 31. Furthermore, the first arm 41 can be raised and lowered using the nozzle drive unit 44, allowing adjustment of the height of the resist supply nozzle 43.

[0042] Furthermore, a resist supply source (not shown) is connected to the resist supply nozzle 43. Additionally, a supply device assembly (not shown) is provided in the supply pipe (not shown) connecting the resist supply nozzle 43 and the aforementioned resist supply source to control the supply of resist from the resist supply source to the resist supply nozzle 43. This supply device assembly includes, for example, a supply valve for switching the supply of resist and stopping the supply, and a flow regulating valve for adjusting the flow rate of the resist.

[0043] A solvent supply nozzle 46, serving as a solvent supply unit, is supported on the second arm 42. The solvent supply nozzle 46 supplies the solvent of the coating liquid to the front side of the wafer W, which is held in the rotating chuck 21. The solvent supplied by the solvent supply nozzle 46 is, for example, an organic solvent such as a diluent. The second arm 42 can move on the track 40 using a moving mechanism for the solvent supply nozzle 46, namely a nozzle drive unit 47 having an actuator such as a motor. As a result, the solvent supply nozzle 46 can be moved from the standby section 48 located on the outer side of the outer cup-shaped body 31 in the positive Y direction to above the periphery of the wafer W inside the outer cup-shaped body 31. Furthermore, the second arm 42 can be raised and lowered using the nozzle drive unit 47, allowing adjustment of the height of the solvent supply nozzle 46.

[0044] Additionally, an organic solvent supply source (not shown) is connected to the solvent supply nozzle 46. Furthermore, a supply device assembly (not shown) for controlling the supply of organic solvent from the supply source to the solvent supply nozzle 46 is provided in the supply pipe (not shown) connecting the solvent supply nozzle 46 and the aforementioned organic solvent supply source. This supply device assembly includes, for example, a supply valve for switching the supply of organic solvent and stopping the supply, and a flow regulating valve for adjusting the flow rate of the organic solvent.

[0045] Furthermore, the solvent supply nozzle 46 is inclined so that the organic solvent released from the solvent supply nozzle 46 is directed downstream of the rotation direction of the wafer W, which is rotated by the rotation holding part 20. In other words, the organic solvent released from the solvent supply nozzle 46 is directed in the direction D (refer to...) Figure 3 The solvent supply nozzle 46 is tilted so that it faces the downstream side of the rotation direction of the wafer W, which is rotated by the rotation holding part 20 when viewed from above.

[0046] like Figure 2 As shown, a cleaning fluid supply nozzle 50 is provided in the portion between the inner cup-shaped body 32 and the rotary chuck 21. The cleaning fluid supply nozzle 50 supplies cleaning fluid to the back side of the wafer W held by the rotary chuck 21. The cleaning fluid supplied by the cleaning fluid supply nozzle 50 is, for example, an organic solvent such as a diluent, and can be the same solvent supplied by the solvent supply nozzle 46.

[0047] Additionally, a cleaning fluid supply source (not shown) is connected to the cleaning fluid supply nozzle 50. Furthermore, a supply device assembly (not shown) for controlling the supply of cleaning fluid from the supply source to the cleaning fluid supply nozzle 50 is provided in the supply pipe (not shown) connecting the cleaning fluid supply nozzle 50 and the aforementioned cleaning fluid supply source. This supply device assembly includes, for example, a supply valve for switching the supply of cleaning fluid and stopping the supply, and a flow regulating valve for adjusting the flow rate of the cleaning fluid.

[0048] A cylindrical wall 31a is provided at the lower part of the outer cup-shaped body 31, and a cylindrical wall 32a is provided at the lower part of the inner cup-shaped body 32. A gap forming the exhaust path d is formed between these walls 31a and 32a. Furthermore, below the inner cup-shaped body 32, a curved passage is formed by a horizontal member 33a that is annular when viewed from above, a cylindrical outer peripheral vertical member 33b and an inner peripheral vertical member 33c, and a bottom member 33d that is annular when viewed from above. This curved passage constitutes a gas-liquid separation section.

[0049] Furthermore, a drain port 34 for discharging the recovered liquid is formed in the portion between the wall 31a and the outer peripheral vertical member 33b in the bottom component 33d, and a drain pipe 35 is connected to the drain port 34.

[0050] On the other hand, an exhaust port 36 is formed in the portion between the outer peripheral vertical member 33b and the inner peripheral vertical member 33c in the bottom member 33d to discharge the atmosphere around the wafer W, and an exhaust pipe 37 is connected to the exhaust port 36.

[0051] Furthermore, a collecting member 60 is provided inside the cup-shaped body 30, above the venting path d formed between the wall 31a of the outer cup-shaped body 31 and the wall 32a of the inner cup-shaped body 32. The collecting member 60 is a component that collects the resist liquid, which extends in a filamentous manner and solidifies, and is made of a metal such as SUS. Furthermore, as described above, the collecting member 60 closes the venting path d, but has an opening 61 that communicates vertically, allowing venting to occur through this opening 61. Moreover, the collecting member 60 is, for example, an annular component when viewed from above, with the openings 61 arranged at equal intervals along the circumference. Furthermore, the collecting member 60 is provided inside the cup-shaped body 30, for example, with its upper surface being approximately horizontal.

[0052] In the above-mentioned resist coating device 1, such as Figure 2 A control unit 100 is shown. The control unit 100 is, for example, a computer with a CPU and memory, and includes a program storage unit (not shown). The program storage unit stores programs for implementing various processes in the resist coating apparatus 1. For example, the program storage unit stores programs for outputting control signals to the aforementioned supply device group, which is respectively provided to the chuck drive unit 22, nozzle drive units 44 and 47, resist liquid supply nozzle 43, solvent supply nozzle 46, and cleaning liquid supply nozzle 50, to implement the wafer processing described later. Alternatively, the aforementioned program may be a program recorded on a computer-readable, non-transitory storage medium, from which it is loaded into the control unit 100. Part or all of the program may also be implemented using dedicated hardware (circuit board).

[0053] (Example of chip processing)

[0054] Next, use Figures 4-6 An example of wafer processing in resist coating apparatus 1 will be described. Figure 4 This is a flowchart illustrating an example of the wafer processing procedure in the resist coating apparatus 1. Figure 5 This is a diagram that roughly illustrates the state of the wafer W during each step of the above wafer processing. Figure 6 This diagram illustrates an example of the position of the solvent supply nozzle 46 during the continuous supply of organic solvent, as described later. Furthermore, the subsequent wafer processing is performed under the control of the control unit 100.

[0055] First, such as Figure 4 As shown, the wafer W is fed into the processing container 10, and is placed and held on the rotating chuck 21 of the rotating holding part 20 (step S1).

[0056] Next, resist solution is supplied to the front side of the wafer W from the resist solution supply nozzle 43 (step S2).

[0057] Specifically, the wafer W held by the rotating chuck 21 is rotated at a speed ω1 (e.g., 50-150 rpm), and as... Figure 5 As shown in (A), resist solution is supplied from resist supply nozzle 43 to the center of the front side Ws of wafer W. As a result, a pool of resist solution is formed in the central region of the front side Ws of wafer W.

[0058] Next, the wafer W is rotated, and the resist solution diffuses on the front side of the wafer W due to the centrifugal force generated by the rotation, forming a resist film on the front side. Organic solvent is then continuously supplied from the solvent supply nozzle 46 to the periphery of the front side of the wafer W (step S3).

[0059] Specifically, in step S2, after forming the resist solution pool and stopping the supply of resist solution from the resist solution supply nozzle 43, the wafer W is rotated at a speed ω2 (e.g., 400-1000 rpm) that is higher than the rotational speed ω1. Due to the centrifugal force at this time, such as Figure 5 The coating liquid on the front side Ws of the wafer W shown in (B) diffuses to the periphery.

[0060] Before the diffused resist reaches the peripheral portion We of the front side Ws of the wafer W, an organic solvent is continuously supplied to the peripheral portion We from the solvent supply nozzle 46. Specifically, for example, the organic solvent is continuously supplied to the peripheral portion We from the solvent supply nozzle 46 immediately after the supply of resist from the resist supply nozzle 43 stops. Thus, at the moment the diffused resist reaches the peripheral portion We and thereafter, the organic solvent can be present in the peripheral portion We; in other words, the peripheral portion We can be pre-wetted with the organic solvent. Therefore, the resist reaching the peripheral portion We of the front side Ws of the wafer W mixes with the organic solvent, and its viscosity decreases. If the viscosity of the resist on the peripheral portion We of the front side Ws of the wafer W decreases as described above, it is difficult to form the aforementioned filamentous portion H (see reference) when it is thrown off from the front periphery. Figure 1 Therefore, in the diffusion step of step S3 and subsequent steps, the generation of cotton-like clumps caused by the resist solution falling from the wafer W can be suppressed.

[0061] In addition, the term "peripheral portion" refers to the portion of the non-device formation area on the front side of the wafer W that is located outside the semiconductor device formation area, such as the portion on the front side of the wafer W that is within 1 mm of the periphery.

[0062] Additionally, when organic solvent is continuously supplied to the periphery We of the front side Ws of the wafer W, the position of the solvent supply nozzle 46 is, for example, as... Figure 6 The image shows the position where the liquid column P formed by the organic solvent released from the solvent supply nozzle 46 contacts the inclined edge B of the peripheral portion of the front side of the wafer W.

[0063] After the resist film is formed, the wafer W is rotated further, the resist film is dried, and organic solvent continues to be supplied from the solvent supply nozzle 46 to the periphery of the front side of the wafer W (step S4).

[0064] Specifically, after the resist solution is diffused across the entire front side (excluding the periphery) of the wafer W in step S2, forming a resist film covering the entire front side (excluding the periphery) of the wafer W, the wafer W is rotated at a speed ω3 (e.g., 1000-1500 rpm), which is higher than the rotational speed ω2. By rotating the wafer W at this speed ω3 for a predetermined time, the resist film on the front side of the wafer W can be dried.

[0065] During this drying process, the resist solution that forms a resist film reaches the periphery of the front side of the wafer W and is thrown off from the periphery of the front side of the wafer W, potentially forming the aforementioned filamentary portion H (see reference). Figure 1 In this example, during the drying step, as follows: Figure 5As shown in (C), organic solvent is continuously supplied from solvent supply nozzle 46 to the peripheral portion We of the front side Ws of wafer W. Specifically, the continuous supply of the organic solvent continues until the drying step is completed. Therefore, when the resist liquid forming the resist film reaches the peripheral portion of the front side of wafer W, it mixes with the organic solvent and its viscosity decreases. If the viscosity of the resist liquid forming the resist film on the peripheral portion of the front side of wafer W decreases as described above, it is difficult for the resist liquid to form the aforementioned filamentous portion (see Figure 1) when it is thrown off from the periphery of the front side. Figure 1 Therefore, in this drying step, the formation of cotton-like clumps caused by the resist solution falling from the wafer W can be suppressed.

[0066] After the drying step, the coating liquid in a predetermined area on the periphery side of the front side of the wafer W is removed using an organic solvent from the solvent supply nozzle 46 (step S5).

[0067] Specifically, after the organic solvent is continuously supplied from the solvent supply nozzle 46 in the drying step of step S4, the coating liquid is then removed from a predetermined area on the peripheral side of the front side of the wafer W (hereinafter also referred to as "peripheral removal of the front side of the wafer"). That is, when turning to the peripheral removal of the front side of the wafer, the solvent is continuously supplied from the solvent supply nozzle 46 without interruption. Furthermore, during the peripheral removal of the front side of the wafer, the wafer W is rotated at a rotational speed ω4 that is approximately the same as the rotational speed ω2.

[0068] Furthermore, the liquid column P, during the continuous supply of organic solvent to the periphery of the front side of the wafer W starting in step S3, is positioned within the area removed from the periphery of the front side of the wafer. If this area removed from the periphery includes a region different from the solvent supply position up to step S4, the solvent supply nozzle can supply organic solvent while moving horizontally along the wafer W, without changing the liquid column P's position within that region.

[0069] In addition, the continuous supply of steps S3 and S4 can be carried out, for example, without changing the flow rate of the organic solvent during the removal of the periphery of the wafer front side in step S5.

[0070] Furthermore, in step S5, the coating liquid that has spread to the back side of the wafer W is also removed.

[0071] Specifically, cleaning fluid is released from the cleaning fluid supply nozzle 50 onto the back side of the wafer W, which rotates at a speed of ω4 as described above. This supplies cleaning fluid to the outer periphery of the back side of the wafer W, compared to the portion released from the cleaning fluid supply nozzle 50, and removes the coating fluid that has spread from the periphery of the front side of the wafer W to the back side. Furthermore, the cleaning fluid supplied to the back side of the wafer W is thrown off from the periphery of the back side of the wafer W and supplied to the collection member 60. Therefore, if lint or similar material is collected by the collection member 60, it can be dissolved and removed.

[0072] In addition, the release position of the cleaning fluid from the cleaning fluid supply nozzle 50 on the back side of the wafer W is more inward than the release position of the organic solvent from the solvent supply nozzle 46 on the front side of the wafer W, for example, a position 80mm to 120mm away from the periphery of the wafer W in a radially inward direction.

[0073] Next, the wafer W is removed from the rotary chuck 21 and sent out from the processing container 10 (step S6).

[0074] Thus, the series of wafer processing in the resist coating apparatus 1 is completed.

[0075] As described above, the wafer processing of this embodiment includes: a step of supplying a resist solution to the front side of the wafer W; and a step of rotating the wafer W to diffuse the supplied resist solution on the front side of the wafer W, thereby forming a resist film on the front side (hereinafter also referred to as the "diffusion formation step"). Furthermore, in the above wafer processing, before the resist solution reaches the periphery of the front side of the wafer W in the diffusion formation step, an organic solvent is continuously supplied from the solvent supply nozzle 46 to the periphery, and this continues at least until the end of the diffusion formation step. Therefore, in the diffusion formation step and subsequent steps, the resist solution on the periphery We of the front side Ws of the wafer W mixes with the organic solvent supplied from the solvent supply nozzle 46, reducing the viscosity. Therefore, when the resist solution is thrown off from the periphery of the front side, it is difficult to form the aforementioned filamentous portion H (see reference). Figure 1 Therefore, according to the wafer processing of this embodiment, the formation of cotton-like clumps caused by the resist solution falling from the wafer W can be suppressed in the diffusion formation step and subsequent steps. As a result, the occurrence of defects caused by cotton-like clumps can also be suppressed.

[0076] Furthermore, in the wafer processing of this embodiment, in the steps necessary for the formation of the resist film (e.g., the diffusion formation step), since the continuous supply of organic solvent from the solvent supply nozzle 46 to the periphery of the front side of the wafer W is carried out in parallel only, the overall processing time is not increased and the production capacity is not reduced.

[0077] Furthermore, it is also considered that the continuous supply of organic solvent during diffusion formation steps, etc., is not from the solvent supply nozzle 46, but from the cleaning liquid supply nozzle 50, which supplies the organic solvent as a cleaning solution to the back side of the wafer W. However, in this case, even if the organic solvent from the cleaning liquid supply nozzle 50 can spread to the periphery of the front side of the wafer W, the area of ​​the portion that comes into contact with the organic solvent on the wafer W and is cooled is too large, which has a significant impact on the film thickness distribution. Therefore, in this embodiment, the continuous supply of organic solvent during diffusion formation steps, etc., is performed from the solvent supply nozzle 46 located above the wafer W, that is, from the front side of the wafer W.

[0078] Furthermore, in the wafer processing of this embodiment, during the resist film drying step following the diffusion formation step, organic solvent is continuously supplied from the solvent supply nozzle 46 to the periphery of the front side of the wafer W. Therefore, the formation of lint-like clumps caused by resist liquid spilled from the wafer W can be further suppressed during the drying step. Moreover, by continuing the continuous supply of the aforementioned organic solvent until the end of the resist film drying step, the formation of lint-like clumps can be further suppressed.

[0079] Furthermore, in this embodiment, when organic solvent is continuously supplied to the peripheral portion of the front side of the wafer W, the position of the solvent supply nozzle 46 is, for example, the position where the liquid column P formed by the organic solvent released from the solvent supply nozzle 46 contacts the edge inclined portion B of the peripheral portion of the surface of the wafer W. As a result, the portion of the organic solvent supplied to the peripheral portion of the front side of the wafer W on the edge inclined portion B side, i.e., the outer peripheral portion, moves outward along the edge inclined portion. On the other hand, the portion of the organic solvent supplied to the peripheral portion of the front side of the wafer W on the inner peripheral side is drawn towards the edge inclined portion B side due to the surface tension of the organic solvent itself, and also moves outward due to the centrifugal force generated by the rotation of the wafer W. Therefore, it is possible to suppress the organic solvent from the solvent supply nozzle 46 from the supply position on the front side of the wafer W to the inner peripheral side. Furthermore, the aforementioned liquid column P, as... Figure 6 As shown, it can also be located inside the periphery of the wafer W. In other words, the width region of the liquid column P located above the liquid-contacting portion of the wafer W can also be located inside the periphery of the wafer W. This prevents the organic solvent released from the solvent supply nozzle 46 from spreading from the periphery of the wafer W downwards to the back surface of the wafer W due to the flow tendency in the release direction.

[0080] Furthermore, in the wafer processing of this embodiment, the solvent supply nozzle 46 is inclined so that the organic solvent released by the solvent supply nozzle 46 is directed downstream of the rotation direction of the wafer W, which is rotated by the rotation holding unit 20. Therefore, it is possible to suppress the generation of organic solvent droplets caused by collision between the organic solvent released from the solvent supply nozzle 46 and the rotating wafer W.

[0081] Furthermore, in this embodiment, after the photoresist film drying step, in which organic solvent is continuously supplied from the solvent supply nozzle 46 to the peripheral portion of the front side of the wafer W until the end of the photoresist film drying step, peripheral removal of the wafer surface using the same solvent supply nozzle 46 is then performed. Moreover, during peripheral removal of the front side of the wafer, solvent is continuously released from the solvent supply nozzle 46 without interruption. Therefore, the formation of cotton-like particles caused by the photoresist can be continuously suppressed throughout the period from the transition to peripheral removal until the peripheral removal is completed.

[0082] Furthermore, the wafer processing of this embodiment can be performed using an existing apparatus with a solvent supply nozzle for removing the periphery of the wafer's front side.

[0083] Furthermore, the resist coating apparatus 1 used for wafer processing in this embodiment is relatively easy to maintain due to its simple structure.

[0084] <Confirmation Test 1>

[0085] The inventors conducted experiments to confirm the effectiveness of using the wafer of the present invention in suppressing the formation of cotton-like clumps.

[0086] In this confirmation test 1, using Figure 2 and Figure 3 The resist coating device 1 shown measures the exhaust pressure (hereinafter referred to as "cup body exhaust pressure") from the exhaust pipe 37 of the cup body 30.

[0087] In the embodiment, the use of Figure 4 and Figure 5 Explanation of chip processing.

[0088] In addition, in Comparative Example 1, a comparison was made with the use of Figure 4 and Figure 5 The wafer processing described differs from the wafer processing in the following aspects. That is, the difference in the wafer processing is that, in steps S2 and S3, organic solvent is not continuously supplied from the solvent supply nozzle 46 to the periphery of the front side of the wafer W.

[0089] In Comparative Example 2, the same wafer processing as in Comparative Example 1 was performed, and an organic solvent as a cleaning liquid was supplied to the back side of the wafer W from the cleaning liquid supply nozzle 50 while the wafer W was rotated in advance, and the collection member 60 was wetted with the organic solvent.

[0090] Figure 7 This is a graph confirming the results of test 1. In Figure 7 In the figure, the horizontal axis represents the elapsed time since the start of the resist supply step S2 described above, and the vertical axis represents the cup-shaped body exhaust pressure.

[0091] like Figure 7 As shown, in Comparative Example 1, the maximum cup-shaped body exhaust pressure was approximately 120 Pa during the drying step in step S4. In contrast, in the embodiment, at the moment when the cup-shaped body exhaust pressure reached its maximum during the drying step in step S4, as in Comparative Example 1, the cup-shaped body exhaust pressure was approximately 75 Pa. That is, in the embodiment, compared to Comparative Example 1, the increase in cup-shaped body exhaust pressure could be suppressed by approximately 40%.

[0092] Furthermore, in Comparative Example 2, the cup-shaped body exhaust pressure reached its maximum of approximately 100 Pa during the drying step in step S4. In contrast, in this embodiment, at the moment when the cup-shaped body exhaust pressure reached its maximum during the drying step in step S4, as in Comparative Example 2, the cup-shaped body exhaust pressure was approximately 75 Pa. That is, in this embodiment, compared to Comparative Example 2, the increase in the cup-shaped body exhaust pressure was suppressed by approximately 25%.

[0093] <Confirmation Test 2>

[0094] In addition, the inventors obtained the film thickness distribution after wafer processing in the above embodiments and the film thickness distribution after wafer processing in Comparative Example 1 above.

[0095] According to the confirmation test 2, the film thickness distribution after wafer processing in the embodiment was not changed compared with the film thickness distribution after wafer processing in Comparative Example 1. That is, no effect on the film thickness distribution of the resist film caused by the continuous supply of organic solvent from the solvent supply nozzle 46 to the periphery of the surface of the wafer W in steps S2 and S3 was confirmed.

[0096] Furthermore, as shown in Comparative Example 2, when an organic solvent was supplied to the back side of wafer W beforehand, not only did the overall wafer processing time increase, but the portion of the back side of wafer W in contact with the organic solvent was also cooled. Therefore, it can be seen that because the portion of the back side of wafer W in contact with the organic solvent is relatively large, it affects the film thickness distribution of wafer W. No such trend was observed in the film thickness distribution after wafer processing in the embodiment.

[0097] <Confirmation Test 3>

[0098] In this confirmatory test 3, the following was used: Figure 2 and Figure 3 The resist coating apparatus 1 shown is used continuously on 5 wafers W. Figure 4 and Figure 5 The wafer processing was described, and the cup-shaped body exhaust pressure was measured at this time.

[0099] Figure 8 This is a graph confirming the results of test 3. In Figure 8 In the diagram, the horizontal axis represents the elapsed time since the start of the resist supply step S2 described above, and the vertical axis represents the cup-shaped body exhaust pressure. Furthermore, in... Figure 8 The results of Comparative Example 1 above are also presented in the comparison.

[0100] like Figure 8 As shown, when five wafers W were processed consecutively, the historical record of the cup-shaped body exhaust pressure remained almost unchanged during the processing. That is, according to the wafer processing of this embodiment, even when multiple wafers W are processed consecutively, the rise in the cup-shaped body exhaust pressure can be stably suppressed.

[0101] <Modifications of this embodiment>

[0102] In the above example, after the supply of the photoresist is stopped, organic solvent is continuously supplied from the solvent supply nozzle 46 to the periphery of the front side of the wafer W. However, the continuous supply can also be started before the supply of the photoresist is stopped. Furthermore, the continuous supply can also be started before the supply of the photoresist is started. However, by starting the continuous supply after the supply of the photoresist is stopped, the consumption of organic solvent can be suppressed.

[0103] Furthermore, in the above examples, the continuous supply of the aforementioned organic solvent is also performed during the drying step of the resist film. However, the continuous supply of the organic solvent can also be omitted during the drying step of the resist film. By also performing the continuous supply of the aforementioned organic solvent during the drying step of the resist film, the formation of cotton-like clumps can be further suppressed. On the other hand, by omitting the continuous supply of the aforementioned organic solvent during the drying step of the resist film, the consumption of organic solvent can be suppressed.

[0104] All aspects of the embodiments disclosed herein are illustrative and should not be considered limiting. The above embodiments can be omitted, substituted, or modified in various ways as long as they do not depart from the claims and their spirit.

Claims

1. A liquid treatment method, characterized in that, include: The step of applying the coating solution to the front side of the substrate; and The step of rotating the substrate to spread the supplied coating liquid on the front side of the substrate, thereby forming a coating film on the front side. In the step of forming the coating film, starting before the coating liquid reaches the peripheral portion of the front side of the substrate, while the substrate is rotating, the solvent of the coating liquid is continuously supplied from the solvent supply section to the peripheral portion in the form of a liquid column, and this continues at least until the step of forming the coating film ends. The solvent is continuously supplied from the solvent supply section to the peripheral portion in such a way that the liquid column formed by the solvent released from the solvent supply section contacts the inclined edge portion of the peripheral portion.

2. The liquid treatment method as described in claim 1, characterized in that: The step of forming the coating film includes a step of rotating the substrate to dry the coating film. During the drying step, the solvent is continuously supplied from the solvent supply section to the peripheral section in the form of a liquid column.

3. The liquid treatment method as described in claim 2, characterized in that: The method includes the following steps: after the drying step, using the solvent from the solvent supply unit to remove the coating liquid from a predetermined area on the peripheral side of the front side of the substrate.

4. The liquid treatment method as described in claim 3, characterized in that: When the solvent is continuously supplied from the solvent supply section to the peripheral portion in the form of a liquid column, the solvent is supplied from the solvent supply section to the area where the coating liquid is removed in the removal step.

5. The liquid treatment method as described in claim 3 or 4, characterized in that: After the solvent is continuously supplied from the solvent supply section to the peripheral section in the form of a liquid column, the removal step is performed, and the solvent is continuously released from the solvent supply section without interruption.

6. A liquid treatment device, characterized in that, include: A rotation holding part that holds the substrate and rotates it; A coating liquid supply unit that supplies coating liquid to the front side of the substrate held by the rotating holding part; A solvent supply section that supplies the solvent of the coating liquid to the front side of the substrate held by the rotating holding section; and Control Department The control unit performs the following steps: The step of supplying coating liquid from the coating liquid supply unit to the front side of the substrate; and The step of rotating the substrate to spread the supplied coating liquid on the front side of the substrate, thereby forming a coating film on the front side. In the step of forming the coating film, a control signal is output so that, starting before the coating liquid reaches the peripheral portion of the front side of the substrate, the solvent is continuously supplied from the solvent supply unit to the peripheral portion in the state of forming a liquid column while the substrate is rotating, and continues at least until the step of forming the coating film ends, so that the solvent is continuously supplied from the solvent supply unit to the peripheral portion in such a way that the liquid column formed by the solvent released from the solvent supply unit contacts the inclined edge portion of the peripheral portion.

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