Periphery coating method, substrate processing apparatus and storage medium

Abstract

To suppress defects in an outer periphery coating of a substrate.SOLUTION: An outer periphery coating method contains: (A) a step of forming a coating film wider than a target width by supplying a coating liquid of an ultraviolet hardening type material to an outer peripheral part of a substrate; (B) a step of selectively irradiating an ultraviolet and hardening the coating film wider than the target width to a predetermined region having the target width; and (C) a step of removing a part to which the ultraviolet is not irradiated and the coating film wider than the target width is not hardened with a solvent.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to a peripheral coating method, a substrate processing apparatus, and a storage medium. [Background technology]

[0002] Patent Document 1 discloses a peripheral coating device that applies a coating liquid to the peripheral portion of a substrate. This device includes a rotational holding unit that holds the substrate horizontally and rotates it, a coating liquid supply unit that is located above the substrate and has a coating liquid nozzle that discharges the coating liquid downward and supplies the coating liquid to the surface of the substrate, a horizontal transport unit that moves the coating liquid nozzle in a horizontal direction, and a coating control unit that controls the rotational holding unit, the coating liquid supply unit, and the horizontal transport unit. The coating control unit controls the rotational holding unit to rotate the substrate, and controls the coating liquid supply unit to discharge the coating liquid from the coating liquid nozzle, while controlling the horizontal transport unit to perform scan-in control to move the coating liquid nozzle from the outside of the peripheral portion of the substrate to above the peripheral portion of the substrate. The coating control unit also controls the rotational holding unit to rotate the substrate, and controls the coating liquid supply unit to discharge the coating liquid from the coating liquid nozzle, while controlling the horizontal transport unit to perform scan-out control to move the coating liquid nozzle from above the peripheral portion of the substrate to the outside of the peripheral portion of the substrate. When the scan-out control is performed, the coating liquid nozzle is moved at a speed slower than the speed at which the coating liquid moves toward the peripheral edge of the substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-110386 A Summary of the Invention [Problem to be solved by the invention]

[0004] The technology disclosed herein suppresses defects in the peripheral coating of a substrate. [Means for solving the problem]

[0005] One aspect of the present disclosure is a peripheral coating method, comprising the steps of: (A) supplying a coating liquid of an ultraviolet-curable material to a peripheral portion of a substrate to form a coating film wider than a target width; (B) selectively irradiating a predetermined region of the coating film wider than the target width with ultraviolet light to cure the region; and (C) removing a portion of the coating film wider than the target width that has not been irradiated with ultraviolet light and has not been cured with a solvent. The step (B) is a step of irradiating the substrate with ultraviolet light while rotating the substrate, and (D) a step of rotating the substrate without supplying the coating liquid before the step (B) to reduce the fluidity of the coating film formed in the step (A) and having a width greater than the target width. of moreover Contains In the step (D), the substrate is rotated at a rotation speed at which the coating liquid discharged from the substrate does not collide with the cup surrounding the outer periphery of the substrate. . Effect of the Invention

[0006] According to the present disclosure, defects in the peripheral coating of a substrate can be suppressed. [Brief description of the drawings]

[0007] [Figure 1] 1 is an explanatory diagram showing an outline of an internal configuration of a coating and developing treatment system including a peripheral coating apparatus as a substrate treatment apparatus according to an embodiment of the present invention; [Diagram 2] 1 is a diagram showing an outline of an internal configuration of a coating and developing treatment system from the front side; [Diagram 3] FIG. 2 is a diagram showing an outline of the internal configuration of the coating and developing treatment system on the rear side. [Figure 4] FIG. 2 is a vertical cross-sectional view showing the outline of the configuration of a peripheral coating device. [Diagram 5] FIG. 2 is a cross-sectional view showing an outline of the configuration of a peripheral coating device. [Figure 6] 13 is a flowchart showing an example of a peripheral coating process. [Figure 7] 1 is a diagram showing the state of the periphery of the surface of a wafer W during peripheral coating processing. [Figure 8] 13 is a diagram for explaining another example of a coating film formation region. FIG. [Figure 9] FIG. 2 is a partially enlarged cross-sectional view showing an example of a wafer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] For example, in a photolithography process in a semiconductor device manufacturing process, a resist liquid is applied to a semiconductor wafer (hereinafter referred to as a "wafer") as a substrate to form a resist film, a pattern is then exposed onto the resist film, and the wafer is then subjected to a development process to form a resist pattern on the wafer surface.

[0009] Incidentally, peripheral coating is known, in which a coating liquid is supplied only to the peripheral portion of a wafer to form a coating film (see Patent Document 1). However, with conventional peripheral coating, liquid splashing occurs when the coating liquid is supplied to the peripheral portion of the wafer, and this liquid splashing can cause defects and other problems.

[0010] Therefore, the technology disclosed herein suppresses defects in the outer periphery coating of a substrate.

[0011] Hereinafter, the peripheral coating method and the substrate processing apparatus according to the present embodiment will be described with reference to the drawings. In this specification and the drawings, elements having substantially the same functional configurations are denoted by the same reference numerals, and duplicated explanations will be omitted.

[0012] <Coating and developing processing system> Fig. 1 is an explanatory diagram showing an outline of the internal configuration of a coating and developing treatment system including a peripheral coating device as a substrate processing apparatus according to this embodiment. Fig. 2 and Fig. 3 are diagrams showing an outline of the internal configuration of the front side and rear side of the coating and developing treatment system 1, respectively.

[0013] 1 to 3, the coating and developing treatment system 1 includes a cassette station 2 into which a cassette C, which is a container capable of accommodating a plurality of wafers, is carried in and out, and a treatment station 3 including a plurality of treatment devices for performing predetermined treatments such as a resist coating treatment. The coating and developing treatment system 1 includes an interface station 5 that transfers the wafer W between the cassette station 2, the treatment station 3, and an exposure device 4 adjacent to the treatment station 3, all of which are integrally connected. The coating and developing treatment system 1 also includes a control unit 6 that controls the coating and developing treatment system 1, including the control of a transport device 70 described below.

[0014] The cassette station 2 is divided into, for example, a cassette loading / unloading section 10 and a wafer transport section 11. For example, the cassette loading / unloading section 10 is provided at the end of the coating and developing processing system 1 on the negative Y direction side (left direction in FIG. 1). The cassette loading / unloading section 10 is provided with a cassette mounting table 12. A plurality of mounting plates 13, for example, four mounting plates 13, are provided on the cassette mounting table 12. The mounting plates 13 are arranged in a row in the horizontal X direction (up and down direction in FIG. 1). The mounting plates 13 can be used to mount the cassettes C when they are loaded or unloaded from the coating and developing processing system 1.

[0015] The wafer transfer section 11 is provided with a transfer device 20 that transfers the wafer W. The transfer device 20 is provided with a transfer path 21 extending in the X direction and a transfer unit 22 that is movable on the transfer path 21. The transfer unit 22 is also movable in the up-down direction and around the vertical axis (θ direction), and can transfer the wafer W between the cassette C on each mounting plate 13 and a transfer device in the third block G3 of the processing station 3, which will be described later.

[0016] The processing station 3 is provided with a plurality of blocks, for example, four blocks G1, G2, G3, and G4, each equipped with various devices. For example, a first block G1 is provided on the front side (negative side in the X direction in FIG. 1) of the processing station 3, and a second block G2 is provided on the rear side (positive side in the X direction in FIG. 1) of the processing station 3. A third block G3 is provided on the cassette station 2 side (negative side in the Y direction in FIG. 1) of the processing station 3, and a fourth block G4 is provided on the interface station 5 side (positive side in the Y direction in FIG. 1) of the processing station 3.

[0017] In the first block G1, as shown in FIG. 2, a plurality of liquid processing devices are arranged in this order from the bottom, such as a development processing device 30 that develops the wafer W, a resist coating device 31 that coats the wafer W with resist liquid to form a resist film, and a peripheral coating device 32 that supplies coating liquid to the peripheral portion of the wafer W to form a coating film.

[0018] For example, three developing treatment devices 30, three resist coating devices 31, and three peripheral coating devices 32 are arranged horizontally. The number and arrangement of the developing treatment devices 30, the resist coating devices 31, and the peripheral coating devices 32 can be selected arbitrarily.

[0019] In the developing treatment device 30 and the resist coating device 31, a predetermined processing liquid is applied onto the wafer W by, for example, a spin coating method. In the spin coating, for example, the processing liquid is discharged onto the wafer W from a discharge nozzle, and the wafer W is rotated to diffuse the processing liquid onto the surface of the wafer W.

[0020] 3, in the second block G2, heat treatment devices 40 for performing heat treatment such as heating and cooling of the wafer W and edge exposure devices 41 for exposing the edge of the resist film on the wafer W are arranged in a vertical and horizontal direction. The number and arrangement of these heat treatment devices 40 and edge exposure devices 41 can also be selected arbitrarily.

[0021] The third block G3 is provided with an inspection device 50 and a plurality of transfer devices 51. The fourth block G4 is provided with a plurality of transfer devices 60.

[0022] 1, a region surrounded by the first block G1 to the fourth block G4 forms a wafer transfer region D. In the wafer transfer region D, a transfer device 70 that transfers, for example, a wafer W is disposed.

[0023] The transfer device 70 has a transfer arm 70a that is movable in, for example, the Y direction, the θ direction, and the vertical direction. The transfer device 70 moves the transfer arm 70a holding the wafer W within the wafer transfer region D, and can transfer the wafer W to a predetermined device within the surrounding first block G1, second block G2, third block G3, and fourth block G4. A plurality of transfer devices 70 are arranged vertically as shown in, for example, FIG. 3, and can transfer the wafer W to a predetermined device at approximately the same height in each of the blocks G1 to G4.

[0024] In addition, in the wafer transfer region D, a shuttle transfer device 71 is provided which linearly transfers the wafer W between the third block G3 and the fourth block G4.

[0025] The shuttle transfer device 71 can move the supported wafer W linearly in the Y direction and transfer the wafer W between the delivery device 51 in the third block G3 and the delivery device 60 in the fourth block G4, which are at approximately the same height.

[0026] 1, a transfer device 72 is provided on the positive side of the X direction of the third block G3. The transfer device 72 has a transfer arm 72a that is movable in, for example, the θ direction and the vertical direction. The transfer device 72 can transfer the wafer W to each delivery device 51 in the third block G3 by moving the transfer arm 70a holding the wafer W up and down.

[0027] The interface station 5 is provided with a transfer device 73 and a delivery device 74. The transfer device 73 has a transfer arm 73a that is movable, for example, in the θ direction and in the vertical direction. The transfer device 73 holds a wafer W on the transfer arm 73a and can transfer the wafer W between each delivery device 60 in the fourth block G4, the delivery device 74, and the exposure device 4.

[0028] The control unit 6 is a computer equipped with a processor such as a CPU, a memory, and the like, and has a program storage unit (not shown). The program storage unit stores a program that controls the operation of the drive systems of the various processing devices and the various transport devices, and controls the wafer processing described below. The program may be recorded in a non-transitory computer-readable storage medium M and installed from the storage medium M to the control unit 6. The storage medium M may be either temporary or non-transitory. A part or all of the program may be realized by dedicated hardware (circuit board).

[0029] <Wafer processing> Next, a description will be given of an example of wafer processing using the coating and developing processing system 1. The following processing is performed under the control of the control unit 6.

[0030] In wafer processing using the coating and developing processing system 1, first, the transfer device 20 removes the wafer W from the cassette C on the cassette mounting table 12 and transfers it to the inspection device 50 in the processing station 3. In the inspection device 50, an image of the surface of the wafer W is captured by an imaging unit (not shown) included in the inspection device 50, and the imaging result is output to the control unit 6. The imaging result is used, for example, to inspect the wafer W.

[0031] Next, the wafer W is transferred by the transfer device 70 to the heat treatment device 40 in the second block G2 and subjected to temperature adjustment processing. Thereafter, the wafer W is transferred to the resist coating device 31 in the first block G1, where a resist film is formed on the wafer W. Thereafter, the wafer W is transferred to the heat treatment device 40 and subjected to a pre-baking process (PAB: Pre-Applied Bake). Note that the pre-baking process, the subsequent PEB (Post Exposure Bake) process, and the post-baking process all perform similar heat treatments. However, the heat treatment devices 40 used for each heat treatment are different from each other.

[0032] Thereafter, the wafer W is transferred to the edge exposure device 41 and subjected to edge exposure processing. Next, the wafer W is transferred to the exposure device 4 and subjected to exposure processing with a predetermined pattern.

[0033] Next, the wafer W is transferred to the heat treatment device 40 and subjected to PEB treatment. Thereafter, the wafer W is transferred to, for example, the development treatment device 30 and subjected to development treatment. After completion of the development treatment, the wafer W is transferred to the heat treatment device 40 and subjected to post-bake treatment.

[0034] Next, the wafer is transferred to the peripheral coating device 32, where a peripheral coating process is performed, and an annular coating film is formed on the surface of the peripheral edge of the wafer W. The peripheral coating process will be described in detail later. Thereafter, the wafer W is transferred to the cassette C on the cassette mounting table 12 by the transfer unit 22 or the like, and a series of photolithography steps is completed.

[0035] <Outer circumference coating device 32> Next, the configuration of the above-mentioned peripheral coating device 32 will be described with reference to Figures 4 and 5. Figures 4 and 5 are vertical and horizontal sectional views showing the outline of the configuration of the peripheral coating device 32, respectively.

[0036] 4 and 5, the peripheral coating device 32 has a processing container 120 whose interior can be sealed. A loading / unloading port (not shown) for the wafer W is formed on the side of the processing container 120, and an opening / closing shutter (not shown) is provided at the loading / unloading port.

[0037] A spin chuck 121 is provided in the processing vessel 120 as a rotary holder that holds and rotates the wafer W. The spin chuck 121 has a horizontal upper surface, and the upper surface is provided with, for example, a suction port (not shown) for sucking the wafer W. The wafer W can be sucked and held on the spin chuck 121 by suction from the suction port.

[0038] The spin chuck 121 is connected to a chuck driving mechanism 122 and can be rotated at a desired speed by the chuck driving mechanism 122. The chuck driving mechanism 122 has a rotation driving source (not shown) such as a motor that generates a driving force for rotating the spin chuck 121. The spin chuck 121 is rotated by the chuck driving mechanism 122, whereby the wafer W is rotated.

[0039] Furthermore, the chuck driving mechanism 122 is provided with a lifting drive source such as a cylinder, and the spin chuck 121 can be lifted and lowered by the chuck driving mechanism 122. When the spin chuck 121 is lifted and lowered by the chuck driving mechanism 122, the wafer W is lifted and lowered. The chuck driving mechanism 122 is controlled by the control unit 6 .

[0040] Lift pins 123 for supporting the wafer W from below and lifting and lowering the wafer W are provided so as to surround the lower side of the spin chuck 121. The lift pins 123 are connected to a pin driving mechanism 124 and can be raised and lowered by the pin driving mechanism 124. The pin driving mechanism 124 enables the lift pins 123 to protrude to a position higher than the upper surface of the spin chuck 121, so that the wafer W can be transferred to and from the spin chuck 121.

[0041] Around the spin chuck 121, there are provided an outer cup 130 that receives and collects liquid scattered or dropped from the wafer W, and an inner cup 140 that is located on the inner periphery side of the outer cup 130. The outer cup 130 surrounds the outer periphery side of the wafer W that rotates while being held by the spin chuck 121, and the inner cup 140 is located below the wafer W held by the spin chuck 121.

[0042] As shown in Fig. 5, rails 150A and 150B extending along the Y direction (left and right direction in Fig. 5) are formed on the negative X direction side (downward in Fig. 5) of the outer cup 130. The rails 150A and 150B are formed, for example, from the outside of the negative Y direction side (left direction in Fig. 5) of the outer cup 130 to the outside of the positive Y direction side (right direction in Fig. 5). Two arms 151 and 152 are provided on the rail 150A, and one arm 153 is provided on the rail 150B.

[0043] The first arm 151 supports a liquid supply nozzle 160 as a coating liquid supply unit. The liquid supply nozzle 160 supplies a coating liquid of an ultraviolet curing material to the surface of the wafer W held by the spin chuck 121. The coating liquid of the ultraviolet curing material is different from the resist liquid used in the resist coating device 31, and is, for example, an ultraviolet curing resin. The ultraviolet curing resin contains, for example, monomers, oligomers, photopolymerization initiators, etc., and when irradiated with ultraviolet light, it changes from a liquid monomer state to a solid polymer state by photopolymerization and hardens. The coating liquid of the ultraviolet curing material has fluidity when it is supplied from the liquid supply nozzle 160 to the surface of the wafer W.

[0044] The first arm 151 is movable on the rail 150A by the nozzle driving mechanism 161. The nozzle driving mechanism 161 has a movement driving source (not shown) such as a motor that generates a driving force for moving the first arm 151. When the first arm 151 moves on the rail 150A by the nozzle driving mechanism 161, the liquid supply nozzle 160 can move from a waiting section 162 installed outside the outer cup 130 on the negative Y-direction side to above the peripheral portion of the wafer W in the outer cup 130. The nozzle driving mechanism 161 is provided with a lifting driving source such as a cylinder, and the first arm 151 can be raised and lowered by the nozzle driving mechanism 161. When the first arm 151 moves up and down by the nozzle driving mechanism 161, the liquid supply nozzle 160 moves up and down. The nozzle driving mechanism 161 is controlled by the control unit 6 .

[0045] A supply source (not shown) of the coating liquid of the ultraviolet curable material is connected to the liquid supply nozzle 160. A supply pipe (not shown) connecting the liquid supply nozzle 160 and the supply source is provided with a group of supply devices (not shown) for controlling the supply of the coating liquid of the ultraviolet curable material from the supply source to the liquid supply nozzle 160. The group of supply devices includes, for example, a supply valve that switches between supply and stop of the coating liquid of the ultraviolet curable material and a flow rate adjustment valve that adjusts the flow rate of the coating liquid. The above-mentioned supply devices are controlled by a control unit 6.

[0046] A solvent supply nozzle 170 serving as a solvent supply unit is supported on the second arm 152. The solvent supply nozzle 170 supplies a solvent to the surface of the wafer W held by the spin chuck 121. The solvent can remove only the uncured portion of the coating film formed on the wafer W by supplying a coating liquid of an ultraviolet curable material, without removing the cured portion.

[0047] The second arm 152 is movable on the rail 150A by the nozzle drive mechanism 171. The nozzle drive mechanism 171 has a movement drive source (not shown) such as a motor that generates a drive force for moving the second arm 152. When the second arm 152 moves on the rail 150A by the nozzle drive mechanism 171, the solvent supply nozzle 170 can move from a waiting section 172 installed outside the Y direction positive side of the outer cup 130 to above the peripheral portion of the wafer W in the outer cup 130. In addition, the nozzle drive mechanism 171 is provided with a lifting drive source such as a cylinder, and the second arm 152 can be lifted and lowered by the nozzle drive mechanism 171. When the second arm 152 moves up and down by the nozzle drive mechanism 161, the solvent supply nozzle 170 moves up and down. The nozzle driving mechanism 171 is controlled by the control unit 6 .

[0048] A solvent supply source (not shown) is connected to the solvent supply nozzle 170. A supply pipe (not shown) connecting the solvent supply nozzle 170 and the supply source is provided with a supply device group (not shown) for controlling the supply of the solvent from the supply source to the solvent supply nozzle 170. The supply device group includes, for example, a supply valve that switches between supply and stop of the solvent and a flow rate adjustment valve that adjusts the flow rate of the solvent. The above-mentioned supply devices are controlled by a control unit 6.

[0049] An irradiation nozzle 180 serving as an irradiation unit is supported on the third arm 153. The irradiation nozzle 180 irradiates the surface of the wafer W held by the spin chuck 121 with ultraviolet light from above. The wavelength of the ultraviolet light irradiated from the irradiation nozzle 180 is, for example, 10 to 500 nm. The irradiation nozzle 180 has, for example, a light source (not shown) that emits ultraviolet light. This light source is controlled by the control unit 6.

[0050] The third arm 153 is movable on the rail 150B by the nozzle driving mechanism 181. The nozzle driving mechanism 181 has a movement driving source (not shown) such as a motor that generates a driving force for moving the third arm 153. The third arm 153 is moved on the rail 150B by the nozzle driving mechanism 181, so that the irradiation nozzle 180 can move from the outside of the Y direction positive side of the outer cup 130 to above the peripheral portion of the wafer W in the outer cup 130. The nozzle driving mechanism 181 is provided with a lifting driving source such as a cylinder, so that the third arm 153 can be lifted and lowered by the nozzle driving mechanism 181. The third arm 153 is lifted and lowered by the nozzle driving mechanism 181, so that the irradiation nozzle 180 is lifted and lowered. The nozzle driving mechanism 181 is controlled by the control unit 6 .

[0051] A supply source (not shown) of the coating liquid of the ultraviolet curable material is connected to the liquid supply nozzle 160. A supply pipe (not shown) connecting the liquid supply nozzle 160 and the supply source is provided with a group of supply devices (not shown) for controlling the supply of the coating liquid of the ultraviolet curable material from the supply source to the liquid supply nozzle 160. The group of supply devices includes, for example, a supply valve that switches between supply and stop of the coating liquid of the ultraviolet curable material and a flow rate adjustment valve that adjusts the flow rate of the coating liquid. The above-mentioned supply devices are controlled by a control unit 6.

[0052] The outer periphery coating device 32 is connected to a control unit 6, which controls the nozzle driving mechanisms 161, 171, 181, the above-mentioned supply equipment group for supplying the coating liquid of the ultraviolet curable material and the solvent, the light source of the irradiation nozzle 180, and the like to form a coating film that is approximately concentric with the wafer W and is annular along the periphery of the surface of the wafer W. Note that this coating film is used, for example, as a protective film for the periphery of the resist pattern. By providing a protective film in this manner, it is possible to prevent the periphery of the resist pattern from being removed, exposing the base, or the resist pattern from becoming abnormally shaped during etching of the wafer W after the protective film is formed.

[0053] <Outer circumference coating treatment> Next, an example of the peripheral coating process in the peripheral coating device 32 will be described. Fig. 6 is a flow chart showing an example of the peripheral coating process. Fig. 7 is a diagram showing the state of the periphery of the surface of the wafer W during the peripheral coating process. The following process is performed under the control of the control unit 6.

[0054] (Step S1) 6, for example, first, the wafer W is carried into the peripheral coating device 32 by the transfer device 70 (step S1). The wafer W carried into the peripheral coating device 32 is transferred from the transfer device 70 to the lift pins 123 that have been raised and are on standby in advance, and then the lift pins 123 are lowered to transfer the wafer W to the spin chuck 121 in the outer cup 130 and hold it by suction.

[0055] (Step S2) 7(a), a coating liquid D1 of an ultraviolet-curable material is supplied to the peripheral portion of the wafer W, and a coating film T1 wider than the target width P is formed (step S2). Specifically, for example, when an unnecessary portion H of the coating film T1 is removed in step S5 described later, the wafer W is rotated so that the unnecessary portion H is formed on the central side of the wafer W, and during the rotation, the coating liquid D1 of an ultraviolet-curable material is supplied, and a ring-shaped coating film T1 wider than the target width P is formed on the surface of the peripheral portion of the wafer W.

[0056] More specifically, the liquid supply nozzle 160 is moved to above the peripheral portion of the wafer W. Thereafter, the wafer W held by the spin chuck 121 is rotated, and during the rotation, the coating liquid D1 of the ultraviolet curing material is supplied from the liquid supply nozzle 160 to the surface of the peripheral portion of the wafer W, inside a region R1 where a coating film of the target width P is to be formed. As a result, a ring-shaped coating film T1 wider than the target width P is formed on the surface of the peripheral portion of the wafer W.

[0057] When the coating liquid D1 of the ultraviolet curing material is supplied, as shown in the figure, the liquid supply nozzle 160 may be inclined so that the coating liquid D1 of the ultraviolet curing material is supplied from the center side of the wafer W toward the outer periphery of the wafer W. More specifically, when the coating liquid D1 of the ultraviolet curing material is supplied, the liquid supply nozzle 160 may be inclined so that the coating liquid D1 of the ultraviolet curing material is supplied from the center side of the wafer W toward the outer periphery of the wafer W from the target width P in a side view. This can prevent the following. That is, the coating liquid of the ultraviolet curing material discharged from the liquid supply nozzle 160 may bounce when it collides with the surface of the wafer W, but it is possible to prevent the rebounded coating liquid from adhering to the center side of the wafer W, i.e., the inside, of the region R1 where the annular coating film of the target width P is formed. The width of the annular coating film formed in step S2 is, for example, 0.5 mm or more larger than the target width, and the distance L from its inner peripheral edge to the peripheral edge of the wafer W is less than 10 mm. The rotation speed of the wafer W in step S2 is, for example, 200 to 700 rpm.

[0058] (Step S3) Next, the wafer W is rotated without supplying the coating liquid D1 of the ultraviolet curing material, thereby reducing the fluidity of the coating film wider than the target width. Specifically, after the supply of the coating liquid D1 of the ultraviolet curable material from the liquid supply nozzle 160 is stopped, the liquid supply nozzle 160 is retreated to the outside of the outer cup 130, and the wafer W is rotated continuously from step S2. This causes a part of the coating liquid constituting the coating film T1 on the surface of the peripheral portion of the wafer W to be discharged, and as a result, the fluidity of the coating film T1 is reduced.

[0059] This step S3 reduces the fluidity of the coating film T1 to an extent that the coating film T1 is not displaced by the rotation of the wafer W when the wafer W is rotated and the coating film is irradiated with ultraviolet rays in step S4 described later. However, this step S3 does not completely eliminate the fluidity of the coating film T1. In other words, this step S3 does not dry the coating film T1. If the coating film T1 dries in this step S3, a bulge (hump) may occur at the outer and inner edges of the surface of the coating film T1, but as described above, the coating film T1 does not dry in this step S3, so the above-mentioned hump can be suppressed.

[0060] For example, in step S3, the wafer W is rotated at a rotation speed at which the coating liquid D1 discharged from the rotating wafer W does not collide with the outer cup 130. This can prevent splashes of the coating liquid D1 that has collided with the outer cup 130. With such a rotation speed, in step S3, the fluidity of the coating film can be reduced to an extent that the coating film T1 is not displaced by the rotation of the wafer W.

[0061] The rotation speed of the wafer W in step S3 may be equal to or higher than that in step S2. Also, step S3 may be omitted.

[0062] (Step S4) Thereafter, a predetermined region R2 having the target width P in the coating film T1 wider than the target width P is selectively irradiated with ultraviolet light U to cure the predetermined region R2. Specifically, the irradiation nozzle 180 is moved to above the peripheral portion of the wafer W. Furthermore, following step S3, the wafer W is rotated, and during the rotation, ultraviolet light from the irradiation nozzle 180 is irradiated toward the surface of the peripheral portion of the wafer W. As a result, the ultraviolet light from the irradiation nozzle 180 is irradiated onto a predetermined annular region R2 having the target width P in the coating film T1 formed on the peripheral portion of the surface of the wafer W and wider than the target width P, and the predetermined annular region R2 is selectively cured. Note that the unnecessary portion H described above is not cured.

[0063] (Step S5) Then, as shown in FIG. 7, the uncured portions of the coating film T1, which are wider than the target width P, that have not been irradiated with ultraviolet light U, i.e., unnecessary portions H, are removed with a solvent D2, thereby forming a cured coating film T2 having the target width P. Specifically, the irradiation of the ultraviolet rays U from the irradiation nozzle 180 is stopped, and the irradiation nozzle 180 is retracted from the outer cup 130, and instead, the solvent supply nozzle 170 is moved to above the peripheral portion of the wafer W. Furthermore, following step S4, the wafer W is rotated, and during the rotation, the solvent D2 from the solvent supply nozzle 170 is supplied to the surface of the peripheral portion of the wafer W. As a result, the uncured portion of the annular coating film T1 wider than the target width P, i.e., the above-mentioned unnecessary portion H, is removed, and an annular coating film T2 having the target width P is formed.

[0064] In step S5, it is preferable to supply the solvent D2 from the uncured portion, i.e., the above-mentioned unnecessary portion H, which is further toward the center of the wafer. This makes it possible to remove the droplets Z of the coating liquid D1 that have bounced back and adhered to the inside of the above-mentioned unnecessary portion H in step S2. In step S5, similarly to step S2, when supplying the solvent, the solvent supply nozzle 170 may be tilted so that the solvent D2 is supplied from the center of the wafer W toward the outer periphery of the wafer W, as shown in the figure.

[0065] (Step S6) Thereafter, the wafer W is unloaded in the reverse order to the loading procedure of the wafer W. This completes a series of peripheral coating processes.

[0066] <Main Effects of This Embodiment> In the above-described outer periphery coating process, the control unit 6 Control to supply a coating solution D1 of ultraviolet curing material to the peripheral portion of the wafer W and form a coating film T1 wider than the target width P Control in which ultraviolet light U is selectively irradiated onto a predetermined region R2 having a target width P in a coating film T1 wider than the target width P, and the predetermined region R2 is cured. ·Controlling to remove an unnecessary portion H that is not irradiated with ultraviolet light U and not cured in a coating film T1 wider than the target width P with a solvent D2 is being performed. That is, in the present embodiment, after forming the coating film T1 wider than the target width P, only the necessary portion is cured, and the unnecessary portion H is washed and removed. Therefore, even if liquid splashing occurs when the coating liquid D1 of the ultraviolet curable material is supplied to the peripheral portion of the wafer W, it can be removed by the solvent D2. Generation of defects caused by this liquid splashing can be suppressed. That is, defects in the outer peripheral coating of the wafer W can be suppressed.

[0067] Also, in the outer peripheral coating process of the present embodiment, as is clear from the above description, heating of the wafer W after forming the coating film is unnecessary. When heating of the wafer W after forming the coating film is required in the outer peripheral coating process, bubbles generated in the coating film during coating film formation expand due to heating of the wafer W, and the portion containing the bubbles may burst, creating holes in the coating film. On the other hand, as described above, in the present embodiment, since heating of the wafer W after forming the coating film is unnecessary, even if bubbles are generated in the coating film T1 during coating film formation, the bubbles do not expand, so it is possible to suppress the formation of holes in the coating films T1 and T2.

[0068] Furthermore, in the conventional outer peripheral coating process, since all the portions where the coating liquid adheres become the coating film, undulations (ripples) caused by the spreading method and discharge accuracy of the coating liquid occur at the inner peripheral end of the annular coating film. According to the outer peripheral coating process of the present embodiment, even if undulations occur at the inner peripheral end of the annular coating film T1 when forming the annular coating film T1, the undulated portion can be removed. That is, according to the present embodiment, an annular coating film T2 without undulations at the inner peripheral end can be obtained. As a result, the device formation region on the wafer W can be effectively utilized.

[0069] Furthermore, the spreading manner of the coating liquid varies depending on the conditions when the coating film T1 is formed (e.g., the rotation speed of the wafer W when the coating liquid is supplied and the amount of liquid discharged) and the type of chemical liquid. Therefore, in conventional peripheral coating processes, it is necessary to adjust the above conditions, for example, for each type of chemical liquid. In contrast, the coating process of this embodiment is highly robust because it does not require adjusting the above conditions for each chemical liquid.

[0070] <Other examples of coating film formation areas> In the above example, a coating film of ultraviolet curing material is formed on the peripheral surface of the portion excluding the bevel of the wafer W. In addition, as shown in Fig. 8, a coating film T1a of ultraviolet curing material having a target width may be formed on the peripheral surface of the wafer W including the bevel W1 by the peripheral processing of this embodiment.

[0071] When forming a coating film T1a of ultraviolet curing material of a target width on the bevel W1, for example, the optical axis of the irradiation nozzle 180 may be made variable and the optical axis may be adjusted according to the irradiated area. This allows the coating film T1a of ultraviolet curing material to be appropriately formed on the bevel W1 of the wafer W. Instead of making the optical axis of the irradiation nozzle 180 variable, the following may be used. That is, a configuration may be adopted in which ultraviolet light from a light source is reflected by a mirror and the reflected light is irradiated onto the bevel W1, the angle of the mirror may be made variable, and the angle of the mirror, i.e., the optical path, may be adjusted according to the irradiated area.

[0072] Furthermore, in the peripheral coating process according to this embodiment, since drying of the coating film is not required and there is no need to rotate the wafer W at high speed, it is possible to prevent a lump of coating liquid constituting the coating film from jumping out of the bevel W1 even when the coating film is formed up to the bevel W1 of the wafer W. Therefore, it is possible to prevent a depression (crater) caused by the above-mentioned lump of coating liquid from being jumped out of the coating film. Furthermore, according to the peripheral coating process of this embodiment, the area on the bevel W1 of the wafer W where the coating film is formed can be easily adjusted.

[0073] The technique according to this embodiment can also be applied to the case where a coating film of an ultraviolet curing material is formed on the rear surface of the peripheral edge of the wafer W.

[0074] <Other examples of peripheral coating treatment> FIG. 9 is a partially enlarged cross-sectional view showing an example of a wafer. 9, a plurality of existing films having different outer circumferential edge positions may be formed on the wafer W. In the example shown in the figure, three existing films F1 to F3 are formed on the wafer W. In this way, even when a plurality of existing films are formed or when a single existing film is formed, the same process as the peripheral coating process described with reference to Fig. 7 is basically performed. However, in the above-mentioned case, the ultraviolet irradiation range in the above-mentioned step S4 may be determined by the control unit 6 based on the outer peripheral end position of the existing film. Also, in the above-mentioned case, the formation region of the coating film in the above-mentioned step S2 may be a sufficiently large range that is predetermined, or may be determined by the control unit 6 based on the outer peripheral end position of the existing film.

[0075] The outer peripheral end position of the existing film is obtained, for example, for each wafer W by referring to device layer information associated with the identification information of the wafer W. The device layer information is a list of information about the films constituting each layer on the wafer W, and includes, for example, information about the film type and information about the pre- and post-processing flows. Furthermore, the outer peripheral end position of the existing film may be obtained from an image of the wafer W captured in advance by an imaging device such as the inspection device 50, for example.

[0076] In the case where the existing films F1 to F3 having different outer circumferential edge positions are formed as described above, in the above-mentioned step S3, as shown in Fig. 9, an area constituting a part of the area from the outer circumferential edge of the existing film F3 located closest to the center of the wafer to the outer circumferential edge of the wafer W may be set as the protection target area, and ultraviolet rays may be irradiated onto the protection target area. In the example shown in the figure, the outer circumferential edge of the existing film F3 and the outer circumferential edge of the wafer W that is not covered by the existing films F1 to F3 are set as the protection target areas A1 and A2.

[0077] In this way, even if there are multiple locations that require protection among the outer circumferential edges of the existing films F1-F3 and the peripheral edge of the wafer W that is not covered by the existing films F1-F3, the protective film, i.e., the coating film T2, can be formed at the multiple locations that require protection in a single outer circumferential coating process. Note that the "locations that require protection" are set to, for example, portions that require suppression of erosion in the subsequent etching.

[0078] The control unit 6 may determine the area where protection is required based on, for example, the device layer information described above. The device layer information includes information on the material properties of the film type and information on the process flow before and after. Based on this information, the control unit 6 may determine whether protection is required in a later process or whether the material of the existing film needs to be protected, and may determine the area where protection is required, i.e., the irradiation range of the ultraviolet light described above, based on the determination result. The area where protection is required may be determined based on an input from a user.

[0079] <Other examples of peripheral coating treatment> The above-mentioned steps S2 to S5 may be repeated in order to laminate the coating film of the target width and thicken the film. By performing step S2 for the second time on the coating film in a cured state by performing step S5 for the first time, a coating film is formed in the range including the cured coating film and its inside. The coating film at that time is in a state of being raised above other areas in the range of the coating film in the cured state. After that, by performing steps S3 to S5 in the same manner again, the coating film in the other areas is removed, and the thickness of the coating film in the cured state increases by the target width. Even if the flow rate and rotation speed are increased, there is a limit to the thickness that can be obtained by one supply and curing due to the fluidity depending on the liquid type and viscosity, and it is not desirable to spread the liquid outside the coating target area on the substrate. Therefore, laminating the coating film by repeated curing multiple times as described above is effective for thickening the film in a local area on the substrate.

[0080] <Modification> In the above example, the peripheral coating process is performed only by the peripheral coating device 32 , but the ultraviolet ray irradiation in the peripheral coating process may be performed by the peripheral exposure device 41 and the other processes may be performed by the peripheral coating device 32 .

[0081] The embodiments disclosed herein should be considered as illustrative and not restrictive in all respects. The above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0082] 6. Control Unit 32 Periphery coating device 121 Spin Chuck 160 Liquid supply nozzle 170 Solvent supply nozzle 180 Irradiation nozzle D1 Coating solution D2 Solvent P target width R2 area T1 Coating film U ultraviolet light W wafer

Claims

1. (A) supplying a coating liquid of an ultraviolet curable material to a peripheral portion of a substrate to form a coating film having a width wider than a target width; (B) selectively irradiating a predetermined region having the target width in the coating film wider than the target width with ultraviolet light to harden the coating film; (C) removing, with a solvent, a portion of the coating film that is wider than the target width and has not been irradiated with ultraviolet light and cured; The step (B) includes irradiating the substrate with ultraviolet light while rotating the substrate; (D) before the step (B), a step of rotating the substrate without supplying the coating liquid to reduce the fluidity of the coating film formed in the step (A) and having a width greater than the target width, The step (D) is a peripheral coating method in which the substrate is rotated at a rotation speed at which the coating liquid discharged from the rotating substrate does not collide with a cup surrounding the outer periphery of the rotating substrate.

2. 2. The periphery coating method according to claim 1, wherein in the step (A), the coating liquid is supplied while rotating the substrate so that the unnecessary portion of the coating film to be removed in the step (C) is formed on the central side of the substrate.

3. The periphery coating method according to claim 2 , wherein in the step (C), the solvent is supplied from a position closer to the center of the substrate than the unnecessary portion.

4. The peripheral coating method according to claim 2 or 3, wherein in the step (A), the coating liquid is supplied from a center side of the substrate toward an outer periphery of the substrate.

5. When an existing film has already been formed on the substrate at the start of the step (A), The peripheral coating method according to any one of claims 1 to 4, further comprising a step of determining an irradiation range of the ultraviolet light in the step (B) based on a position of an outer peripheral edge of the existing film.

6. In the case where a plurality of existing films having different outer circumferential end positions are formed, The edge coating method according to claim 5 , wherein the (B) step irradiates the ultraviolet light to a protection target area constituting a part of the area from the outer edge of the existing film located closest to the center of the substrate to the outer edge of the substrate.

7. The periphery coating method according to any one of claims 1 to 6, wherein the steps (A) to (C) are repeated to stack the coating film of a target width to form a thick film.

8. A readable computer storage medium storing a program that runs on a computer of a control unit that controls a substrate processing apparatus so as to cause the substrate processing apparatus to execute the edge coating method according to any one of claims 1 to 7.

9. A substrate processing apparatus for processing a substrate, a rotation holder that holds and rotates the substrate; a coating liquid supply unit that supplies a coating liquid of an ultraviolet curable material to the substrate held by the rotating holder; an irradiation unit that irradiates ultraviolet light onto the substrate held by the rotation holder; a solvent supply unit that supplies a solvent to the substrate held by the spin holder; a cup surrounding an outer periphery of the substrate rotated by the rotating holder; A control unit, supplying the coating liquid to a peripheral portion of a substrate to form a coating film having a width greater than a target width; Control of selectively irradiating ultraviolet light onto a predetermined region having the target width in the coating film that is wider than the target width, thereby hardening the predetermined region; and removing a portion of the coating film that is wider than the target width and that has not been irradiated with ultraviolet light and has not been cured with a solvent. In the curing control, the ultraviolet light is irradiated while rotating the substrate; Before the control of hardening, a control is further performed to rotate the substrate without supplying the coating liquid, and to reduce the fluidity of the coating film formed by the control of forming and having a width greater than the target width; In the control of decreasing the rotation speed, the substrate is rotated at a rotation speed at which the coating liquid discharged from the rotating substrate does not collide with the cup.

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