TW201740432A - Substrate processing method, substrate processing device, and computer readable recording medium - Google Patents

Abstract

While controlling the shape of the photoresist thick film, the ridge is removed. The processing method of the wafer (W) includes the first project, the coating liquid is supplied to the surface (Wa) of the wafer (W) to form a coating film, and the second project is to discharge the organic film from the nozzle (46). The solvent is supplied to the peripheral portion of the coating film, and the raised portion of the peripheral portion is convexly convex and flattened to the same thickness as the other portions of the coating film. The third project is in the second project. After that, the coating film is heated to form a cured film in which the coating film is cured. In the fourth step, the organic solvent is discharged from the nozzle (46) and supplied to the peripheral portion of the cured film, and the peripheral portion is dissolved and removed from the substrate.

Description

Substrate processing method, substrate processing device, and computer readable recording medium

The present disclosure relates to a substrate processing method, a substrate processing apparatus, and a computer readable recording medium.

In the production of MEMS (MicroElectro Mechanical Systems) or the like, a photoresist film (thickness thick film) having a thickness of, for example, about 5 μm to 60 μm is formed on the surface of the substrate in order to process the substrate three-dimensionally. . As a material of the photoresist film, for example, a coating liquid (for example, polyimide) having a high viscosity and being difficult to flow on the surface of the substrate can be used. When the coating liquid having such a high viscosity is dropped on the surface of the substrate and spin-coated, a convex protrusion (so-called bulging) is formed on the peripheral portion of the substrate, and the thickness of the photoresist film is particularly thick, which may cause The in-plane uniformity of the photoresist film is reduced.

Therefore, Patent Document 1 discloses a substrate processing method including a step of dropping a coating liquid on a surface of a substrate to form a photoresist film, a step of heating the photoresist film to be cured, and an organic layer; The solvent is supplied to the peripheral portion of the cured photoresist film (cured film) to remove the peripheral portion. Thick film of photoresist due to curing by heating a thick film Since the solvent in the inside volatilizes, the cured film has higher solubility with respect to an organic solvent than before curing. Therefore, the peripheral portion of the photoresist film which is likely to be the cause of the reduction in in-plane uniformity can be easily removed together with the ridge.

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. Hei 11-333355

However, since the film thickness of the peripheral portion of the photoresist film is particularly thick, it is difficult to remove only the peripheral portion of the photoresist film by the organic solvent. Therefore, there is a possibility that the end surface of the photoresist film after the removal of the peripheral portion is collapsed, and it is difficult to control the shape of the photoresist film.

Therefore, the present disclosure describes a substrate processing method, a substrate processing apparatus, and a computer-readable recording medium that can remove the raised surface while controlling the shape of the photoresist film.

The substrate processing method according to one aspect of the present invention includes a first step of supplying a coating liquid onto a surface of a substrate to form a coating film, and a second project of discharging the first organic solvent from the first nozzle and supplying the coating film to the coating material. The peripheral portion of the film is dissolved in the convex portion of the peripheral portion to be convex and flattened to the same thickness as the other portions of the coating film; the third project, after the second project, is heated and coated. In the fourth step, the second organic solvent is discharged from the second nozzle and supplied to the peripheral portion of the cured film, and the peripheral portion is dissolved and removed from the substrate.

In the second aspect of the invention, the first organic solvent is discharged from the first nozzle and supplied to the peripheral portion of the coating film, and then heated in the third and fourth projects. The curing of the coating film and the supply of the second organic solvent to the peripheral portion of the cured film. The coating film (uncured film) before curing tends to be less soluble in an organic solvent than the coating film (cured film) after curing. Therefore, the first organic solvent supplied in the second project does not remove the peripheral portion of all the uncured film, but particularly removes the raised portion in the peripheral portion. In this manner, before the third and fourth works, the thickness of the peripheral portion of the coating film is made similar to that of the other regions by removing the ridge portion from the coating film in advance. Therefore, in the next fourth step, the removal of the peripheral portion of the cured film is facilitated, and the end surface of the cured film after the removal of the peripheral portion becomes less likely to collapse. As a result, the shape of the photoresist film can be controlled while removing the ridge.

However, the ridge portion of the peripheral portion of the coating film has a predetermined width. Therefore, when all the peripheral portions are removed together with the ridges by the organic solvent, the coating liquid may be wasted to cause an increase in cost, and it is possible to narrow the area in which the electronic components can be manufactured in the substrate to cause a decrease in productivity. However, the substrate processing method of one aspect of the present disclosure is In the second project, the ridges were removed. Therefore, it is not necessary to remove all the peripheral portions in order to remove the ridges. Therefore, when a coating film (cured film) is formed on the surface of the substrate, cost reduction and productivity improvement can be achieved.

The solubility in the constituent components of the coating film and the cured film in the first organic solvent may be the same as or higher than the solubility of the constituent components of the coating film and the cured film in the second organic solvent. high. In this case, the first organic solvent can effectively dissolve the uncured film which is more difficult to dissolve in the organic solvent than the cured film.

In the fourth step, the second organic solvent may be discharged from the second nozzle or the discharge port of the second nozzle may be discharged from the substrate while the discharge port of the second nozzle is vertically downward with respect to the surface of the substrate. The center portion is inclined obliquely downward toward the peripheral portion, and the second organic solvent is discharged from the second nozzle. In this case, it becomes difficult for the second organic solvent supplied to the peripheral portion of the cured film to splash toward the center portion of the substrate. Therefore, it becomes easy to ensure the in-plane uniformity of the coating film.

In the second aspect, the first organic solvent may be discharged from the first nozzle, and the first nozzle may be moved from the peripheral edge of the substrate toward the center portion side of the peripheral edge at a first speed; When the first nozzle discharges the first organic solvent, the first nozzle moves from the position toward the periphery of the substrate at a second speed that is slower than the first speed. When the first nozzle is discharged from the first nozzle, the first nozzle is moved from the peripheral edge of the substrate toward the center portion of the peripheral edge, and the first organic solvent is discharged at the position. 1 Organic solvents become more difficult to splash around. One side of the first organic solvent is discharged from the first nozzle When the first nozzle is moved from the position toward the periphery of the substrate, it is more difficult to cause a part of the predetermined portion to be removed, and it becomes more difficult to cause the second organic solvent to be discharged in a state of staying at the predetermined portion. It is easy to ensure the in-plane uniformity of the coated film. By moving the first nozzle toward the peripheral edge of the substrate, the second speed is slower than the first speed, and the removal of the ridge portion can be promoted in a state where it is difficult for the first organic solvent to flow to the center portion of the substrate.

The substrate processing apparatus according to another aspect of the present invention includes: a coating liquid supply unit configured to supply a coating liquid to a surface of the substrate; and a solvent supply unit configured to supply the first and second organic solvents to the substrate a surface; a heating unit configured to heat the substrate; and a control unit, wherein the solvent supply unit includes: a first nozzle that can discharge the first organic solvent; and a second nozzle that can discharge the second organic solvent, and the control unit executes: In the first treatment, the coating liquid is supplied to the surface of the substrate to form a coating film by controlling the coating liquid supply portion, and the second organic solvent is controlled from the second processing by controlling the solvent supply portion. (1) The nozzle is discharged and supplied to the peripheral edge portion of the coating film, and the raised portion of the peripheral portion is convexly convex and flattened to the same thickness as the other portions of the coating film. The third treatment is performed. After the treatment, the coating film is heated to form a cured film having a cured coating film by controlling the heating portion, and the fourth treatment is performed to control the solvent supply portion so that the second organic solvent is from the second The nozzle is spit out and supplied to the cured film. Edge portion, the peripheral edge portion of the dissolved and removed from the substrate.

In the substrate processing apparatus according to another aspect of the present invention, the first organic solvent is discharged from the first nozzle and supplied to the coating film in the second processing. In the peripheral portion, thereafter, in the third and fourth treatments, the curing of the coating film by heating and the supply of the second organic solvent to the peripheral portion of the cured film are performed. The coating film (uncured film) before curing tends to be less soluble in an organic solvent than the coating film (cured film) after curing. Therefore, the first organic solvent supplied in the second project does not remove all the peripheral portions of the coating film before curing, but particularly removes the raised portions in the peripheral portion. In this manner, before the third and fourth treatments, the thickness of the peripheral portion of the coating film is made equal to the other regions by removing the ridge portion from the coating film in advance. Therefore, in the next fourth treatment, the removal of the peripheral portion of the cured film is facilitated, and the end surface of the cured film after the removal of the peripheral portion becomes less likely to collapse. As a result, the shape of the photoresist film can be controlled while removing the ridge.

However, the ridge portion of the peripheral portion of the coating film has a predetermined width. Therefore, when all the peripheral portions are removed together with the ridges by the organic solvent, the coating liquid may be wasted to cause an increase in cost, and it is possible to narrow the area in which the electronic components can be manufactured in the substrate to cause a decrease in productivity. However, in the substrate processing apparatus according to another aspect of the present disclosure, the ridge portion is removed in the second process. Therefore, it is not necessary to remove all the peripheral portions in order to remove the ridges. Therefore, when a coating film (cured film) is formed on the surface of the substrate, cost reduction and productivity improvement can be achieved.

The solubility in the constituent components of the coating film and the cured film in the first organic solvent may be the same as or higher than the solubility of the constituent components of the coating film and the cured film in the second organic solvent. high. In this case, the first organic solvent can be effectively dissolved more than the cured film. It is difficult to dissolve in a coating film before curing of an organic solvent.

In the fourth processing, the second organic solvent may be discharged from the second nozzle or the second nozzle may be placed in a state where the discharge port of the second nozzle is vertically downward with respect to the surface of the substrate. The second organic solvent is discharged from the second nozzle in a state where the discharge port of the nozzle is inclined obliquely downward from the center portion of the substrate toward the peripheral portion. In this case, it becomes difficult for the second organic solvent supplied to the peripheral portion of the cured film to splash toward the center portion of the substrate. Therefore, it becomes easy to ensure the in-plane uniformity of the coating film.

In the second process, the first nozzle is configured to eject the first organic solvent from the first nozzle, and to position the first nozzle from the peripheral edge of the substrate toward the center portion side of the peripheral edge at the first speed. And moving the first organic solvent from the first nozzle to move the first nozzle from the position toward the periphery of the substrate at a second speed slower than the first speed. When the first nozzle is discharged from the first nozzle, the first nozzle is moved from the peripheral edge of the substrate toward the center portion of the peripheral edge, and the first organic solvent is discharged at the position. 1 Organic solvents become more difficult to splash around. When the first organic solvent is discharged from the first nozzle and the first nozzle is moved from the position toward the periphery of the substrate, it is more difficult to cause the second organic solvent to be discharged when the second organic solvent is discharged while staying at the predetermined portion. In particular, the case where the predetermined portion is removed is made, and it becomes easy to ensure the in-plane uniformity of the coating film. By moving the first nozzle toward the peripheral edge of the substrate, the second speed is slower than the first speed, and the removal of the ridge portion can be promoted in a state where it is difficult for the first organic solvent to flow to the center portion of the substrate.

A computer-readable recording medium according to another aspect of the present invention is a program for recording a substrate processing method for causing a substrate processing apparatus to execute the above-described substrate processing method. The computer-readable recording medium of the other aspect of the present disclosure can remove the ridges while controlling the shape of the photoresist film as in the above-described substrate processing method. In the present specification, a computer-readable recording medium includes: a non-transitory computer recording medium (for example, various main memory devices or auxiliary memories) or a transmission signal (transitory). Computer recording medium) (for example, a data signal that can be provided via a network).

According to the substrate processing method, the substrate processing apparatus, and the computer-readable recording medium of the present disclosure, the shape of the photoresist film can be controlled while removing the ridge.

1‧‧‧Substrate processing system (substrate processing device)

2‧‧‧ Coating development device (substrate processing device)

10‧‧‧Controller (Control Department)

20‧‧‧Rotary Holder

30‧‧‧ Coating Liquid Supply Department

40‧‧‧Solvent supply department

46‧‧‧Nozzles (1st and 2nd nozzles)

R‧‧‧Photoresist film

RM‧‧ record media

U1‧‧‧ Coating unit

U2‧‧‧heat treatment unit (heating unit)

W‧‧‧ wafer (substrate)

Fig. 1 is a perspective view showing a substrate processing system.

FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1. FIG.

Fig. 3 is a sectional view taken along line III-III of Fig. 2;

Fig. 4 is a schematic view showing a coating unit.

Fig. 5 is a block diagram showing a substrate processing system.

Fig. 6 is a schematic view showing a hardware configuration of a controller.

[Fig. 7] Fig. 7 shows the result of a dripping test of an organic solvent Figure.

Fig. 8 is a flow chart for explaining a procedure for forming a photoresist film.

Fig. 9 is a schematic view for explaining a forming order of a photoresist film.

Fig. 10 is a schematic view for explaining a formation order of a photoresist film.

Since the embodiments of the present disclosure described below are illustrative of the present invention, the present invention is not limited to the following. In the following description, the same elements or elements having the same functions are denoted by the same reference numerals, and the description thereof will not be repeated.

[Substrate processing system]

As shown in FIG. 1, the substrate processing system 1 (substrate processing apparatus) includes a coating development apparatus 2 (substrate processing apparatus), an exposure apparatus 3, and a controller 10 (control unit). The exposure device 3 performs exposure processing (pattern exposure) of the photosensitive resist film formed on the surface Wa (see FIG. 4) of the wafer W (substrate). Specifically, the exposure target portion of the photosensitive resist film (photosensitive film) is selectively irradiated with an energy ray by a method such as immersion exposure. Examples of the energy line include an ArF excimer laser, a KrF excimer laser, a g line, an i line, or an extreme ultraviolet (EUV: Extreme Ultraviolet).

The coating development apparatus 2 performs a photosensitive photoresist film or a non-photosensitive photoresist film on the surface Wa of the wafer W before exposure processing by the exposure apparatus 3 (hereinafter, collectively referred to as "resist film" Processing of R" (see Figure 4)). The application of the developing device 2 is performed after exposure processing of the photosensitive resist film by the exposure device 3, and then development processing of the photosensitive resist film is performed. The wafer W may also have a circular plate shape, or may have a corner portion of a circular shape, or a shape other than a circle such as a polygon. The wafer W may be, for example, a semiconductor substrate, a glass substrate, a mask substrate, or a FPD (Flat Panel Display) substrate. The diameter of the wafer W may be, for example, about 200 mm to 450 mm.

As shown in FIGS. 1 to 3, the application developing device 2 is provided with a carrier block 4, a processing block 5, and an interface block 6. The carrier block 4, the processing block 5, and the interface block 6 are arranged in a horizontal direction.

As shown in FIGS. 1 and 3, the carrier block 4 has a carrier station 12 and a loading/unloading unit 13. The carrier station 12 supports a plurality of carriers 11. The carrier 11 accommodates at least one wafer W in a sealed state. A switch door (not shown) for taking out the wafer W is provided on the side surface 11a of the carrier 11. The carrier 11 is detachably provided on the carrier station 12 so that the side surface 11a faces the loading/unloading portion 13 side.

The loading/unloading unit 13 is located between the carrier station 12 and the processing block 5. The loading/unloading unit 13 has a plurality of opening and closing doors 13a. When the carrier 11 is placed on the carrier station 12, it becomes the state of the switch door of the carrier 11 to the switch door 13a. The inside of the carrier 11 and the loading/unloading unit 13 are connected in such a manner that the opening and closing doors 13a and the opening and closing doors of the side surface 11a are simultaneously opened. through. The loading/unloading unit 13 has a receiving arm A1 built therein. The arm A1 is taken out, and the wafer W is taken out from the carrier 11 and transferred to the processing block 5, and the wafer W is received from the processing block 5 and returned to the carrier 11.

The processing block 5 has a BCT module 14, an HMCT module 15, a COT module 16, and a DEV module 17, as shown in FIGS. 1 and 2. The BCT module 14 is an underlayer film forming module. The HMCT module 15 is an intermediate film (hard mask) forming a module. The COT module 16 is a photoresist film forming module. The DEV module 17 is a development processing module. The modules are arranged from the ground side in the order of the DEV module 17, the BCT module 14, the HMCT module 15, and the COT module 16.

The BCT module 14 is configured to form an underlayer film on the surface Wa of the wafer W. The BCT module 14 is internally provided with a plurality of coating units (not shown), a plurality of heat treatment units (not shown), and a transfer arm A2 for transporting the wafers W to the units (see FIG. 2). . The coating unit is configured to apply a coating liquid for forming an underlayer film on the surface Wa of the wafer W to form a coating film. The heat treatment unit is configured to heat the wafer W by, for example, a hot plate, and heat-treat the heated wafer W by, for example, a cooling plate. Specific examples of the heat treatment performed in the BCT module 14 include a heat treatment for curing the coating film to form a lower layer film. Examples of the underlayer film include a reflection preventing (SiARC) film.

The HMCT module 15 is configured to form an intermediate film on the underlayer film. The HMCT module 15 is internally provided with a plurality of coating units (not shown), a plurality of heat treatment units (not shown), and a transfer arm A3 for transporting the wafers W to the units (see FIG. 2). . Coating unit, which is configured to be in the middle The coating liquid for forming an interlayer film is applied onto the surface Wa of the wafer W to form a coating film. The heat treatment unit is configured to heat the wafer W by, for example, a hot plate, and heat-treat the heated wafer W by, for example, a cooling plate. Specific examples of the heat treatment performed in the HMCT module 15 include a heat treatment for curing the coating film to form an intermediate film. Examples of the intermediate film include an SOC (Spin On Carbon) film and an amorphous carbon film.

The COT module 16 is configured to form a thermosetting photoresist film R on the interlayer film. As shown in FIG. 2 and FIG. 3, the COT module 16 has a plurality of coating units U1, a plurality of heat treatment units U2 (heating units), and a transfer arm A4 for transporting the wafers W to the units. . The coating unit U1 is configured by coating a treatment liquid (photoresist) for forming a photoresist film on the intermediate film to form a coating film. The detailed coating unit U1 will be described later. The heat treatment unit U2 is configured to heat the wafer W by, for example, a hot plate, and heat-treat the heated wafer W by, for example, a cooling plate. Specific examples of the heat treatment performed by the COT module 16 include a heat treatment (PAB: Pre Applied Bake) for curing the coating film to form the photoresist film R.

The DEV module 17 is configured to perform development processing of the exposed photosensitive resist film. The DEV module 17 includes a plurality of developing units (not shown), a plurality of heat treatment units (not shown), a transfer arm A5 for transporting the wafers W to the units, and a direct transfer arm A6. The wafer W is transferred without passing through the cells. The developing unit is configured to partially remove the photosensitive photoresist film to form a photoresist pattern. The heat treatment unit is configured as The wafer W is heated by, for example, a hot plate, and the heated wafer W is cooled by, for example, a cooling plate to perform heat treatment. Specific examples of the heat treatment performed by the DEV module 17 include heat treatment (PEB: Post Exposure Bake) before development processing, and heat treatment (PB: Post Bake) after development processing.

On the side of the carrier block 4 in the processing block 5, as shown in Figs. 2 and 3, a scaffolding unit U10 is provided. The scaffolding unit U10 is disposed from the ground throughout the HMCT module 15, and is divided into a plurality of units arranged in the vertical direction. In the vicinity of the scaffolding unit U10, a lifting arm A7 is provided. The lifting arm A7 moves the wafer W up and down between the units of the scaffolding unit U10.

On the side of the interface block 6 in the processing block 5, a scaffolding unit U11 is provided. The scaffolding unit U11 is provided from the ground above the upper portion of the DEV module 17, and is divided into a plurality of units arranged in the vertical direction.

The interface block 6 has a receiving arm A8 built therein and is connected to the exposure device 3. The arm A8 is configured to take out the wafer W of the rack unit U11 and transfer it to the exposure device 3, and receive the wafer W from the exposure device 3 to return to the rack unit U11.

The controller 10 controls the substrate processing system 1 in part or in whole. The detailed controller 10 will be described later.

[Composition of coating unit]

Next, referring to FIG. 4, the development coating unit will be described in more detail. U1. As shown in FIG. 4, the coating unit U1 includes a rotation holding unit 20, a coating liquid supply unit 30, and a solvent supply unit 40.

The rotation holding portion 20 has a rotating portion 21 and a holding portion 22. The rotating portion 21 has a shaft 23 that protrudes above. The rotating portion 21 rotates the shaft 23 by using, for example, an electric motor or the like as a power source. The holding portion 22 is provided at the front end portion of the shaft 23. The wafer W is disposed on the holding portion 22. The holding portion 22 holds the wafer W horizontally by, for example, adsorption or the like. In other words, the rotation holding portion 20 rotates the wafer W around the axis (vertical axis) perpendicular to the surface Wa of the wafer W in a state where the posture of the wafer W is substantially horizontal. In the present embodiment, since the rotation axis passes through the center of the wafer W having a circular shape, it is also a central axis. In the present embodiment, as shown in FIG. 4, the holding portion 20 is rotated, and the wafer W is rotated counterclockwise as viewed from above.

The coating liquid supply unit 30 is configured to supply the coating liquid to the surface Wa of the wafer W. The coating liquid supply unit 30 includes a coating liquid source 31, a pump 32, a valve 33, a nozzle 34, and a pipe 35. The coating liquid source 31 has a function of a supply source of the coating liquid L1. The coating liquid L1 to be stored in the coating liquid source 31 is, for example, a photosensitive photoresist material which is a photosensitive photoresist film, a non-photosensitive photoresist material which is a non-photosensitive photoresist film, and the like. In order to form a photoresist film R having a film thickness of, for example, about 5 μm to 60 μm, a material having a viscosity of, for example, 1000 cP or more and having difficulty in flowing on the surface Wa of the wafer W (for example, polyimide) may be used. One of these photoresist materials.

The pump 32 sucks the coating liquid L1 from the coating liquid source 31. The pipe 35 and the valve 22 are sent to the nozzle 34. The nozzle 34 is disposed above the wafer W such that the discharge port faces the surface Wa of the wafer W. The nozzle 34 is configured to be movable in the horizontal direction and the vertical direction by a driving unit (not shown). Specifically, the nozzle 24 moves linearly in a direction perpendicular to the rotation axis of the wafer W along the radial direction of the wafer W when the coating liquid L1 is discharged. The nozzle 34 is raised to a position away from the holding portion 22 when the wafer W is held by the holding portion 22, and is lowered to near the wafer when the wafer W is held by the holding portion 22 and the coating liquid is discharged. The approach position of W (holding portion 22). The nozzle 34 can discharge the coating liquid L1 sent from the pump 32 to the surface Wa of the wafer W. The piping 35 is connected to the coating liquid source 31, the pump 32, the valve 33, and the nozzle 34 in this order from the upstream side.

The solvent supply unit 40 is configured to supply one or two or more types of organic solvents (first and second organic solvents) to the surface Wa of the wafer W. In the present embodiment, the coating liquid supply unit 30 includes solvent sources 41 and 42, pumps 43, 44, valves 45, nozzles 46, and pipes 47 to 49. The solvent sources 41, 42 function as a supply source of an organic solvent. As the organic solvent to be stored in the solvent sources 41 and 42, various diluents can be used, and for example, 70% by mass of propylene glycol monomethyl ether (PGME) and 30% by mass of propylene glycol methyl ether acetate (PGMEA) are mixed. Diluent (OK73 thinner: manufactured by Tokyo Ohka Kogyo Co., Ltd.), a diluent (70% by mass of propylene glycol monomethyl ether (PGMEA), and 30% by mass of cyclohexanone (CHN) (manufactured by JSR Co., Ltd.), Diluent, cyclohexanone, acetone C- mixed with 95% by mass of α-butyrolactone and 5% by mass of anisole 260 (manufactured by Merck KGaA), etc.

The solvent sources 41, 42 can also store the same organic solvent, or can store different organic solvents. When the solvent sources 41, 42 store different organic solvents, the solubility of the constituents of the coating liquid stored in the organic solvent L2 of the solvent source 41 with respect to the coating liquid source 31 may be stored in a solvent source. The solubility in the organic solvent L3 of 42 is the same as or higher than the composition of the coating liquid. The solubility of the organic solvent can also be practically carried out by dropping the organic solvent onto the coating film formed on the surface Wa of the wafer W, and the ease of dissolution according to the coating film (indicating the unit per unit of the coating film) The amount of time dissolved) was evaluated. Or, the solubility of the organic solvent, in addition to the above solubility, can also comprehensively consider the permeability of the organic solvent (whether the end surface of the organic solvent dissolves the coating film is smooth) and the ease of expansion of the organic solvent (organic solvent) The dissolution area of the coating film was dissolved and evaluated.

Here, an outline of the dropping test and the evaluation method of the solubility will be described using the following three organic solvents A, B, and C as an example.

Organic solvent A: a diluent in which cyclohexanone and n-butyl ester are mixed in a predetermined ratio

Organic solvent B: cyclohexanone

Organic solvent C: A diluent in which PGME and OK73 thinner are mixed in a predetermined ratio

Specifically, first, the coating liquid L1 (non-photosensitive polyimide solvent solution) of the coating liquid source 31 is supplied from the nozzle 34 to the surface Wa of the wafer W, and coating is formed on the surface Wa of the wafer W. Membrane (non-photosensitive polypeptone) Imine film). The thickness of the coating film was 60 μm. Next, one drop (10 ml) of each of the organic solvents A, B, and C was dropped on each of the portions of the coating film (the uncured film before curing by heating). Thereafter, the solubility, the susceptibility, and the ease of expansion with respect to the constituent components of the coating liquid L1 were observed. 7(a) is a schematic view showing a state in which the organic solvent A is dropped on the coating film; and FIG. 7(b) is a schematic view showing a state in which the organic solvent B is dropped on the coating film; (c) is a schematic view showing a state in which the organic solvent C is dropped on the coating film.

As a result of the above dropping test, the organic solvent A immediately dissolves the coating film, whereas the organic solvent C takes time to dissolve the coating film. Therefore, the solubility with respect to the constituent component of the coating liquid L1 increases in the order of the organic solvent A, the organic solvent B, and the organic solvent C (solubility: organic solvent A > organic solvent B > organic solvent C). When the organic solvent B dissolves the end surface of the coating film, it is extremely smooth (see FIG. 7(b)). On the other hand, when the organic solvent B dissolves the coating film, a large number of irregularities are generated (see the figure). 7(c)). Therefore, the degree of permeation with respect to the constituent components of the coating liquid L1 is increased in accordance with the order of the organic solvent C, the organic solvent A, and the organic solvent B (permeability: organic solvent C > organic solvent A > organic solvent B) . When the organic solvent A was dropped, the diameter of the pores formed in the coating film was about 52.2 mm (see Fig. 7 (a)), and when the organic solvent B was dropped, the diameter of the pores generated in the coating film was about 27.4. Mm (see Fig. 7(b)), when the organic solvent C was dropped, the diameter of the pores formed in the coating film was about 42.4 mm (see Fig. 7(c)). Therefore, the ease of expansion of the constituent components of the coating liquid L1 is based on the organic solvent A and the organic solvent. C. The order of the organic solvent B becomes high (equivalent: organic solvent A > organic solvent C > organic solvent B). From the above, from the viewpoint of solubility alone, the solubility in the constituent component of the coating liquid L1 is the highest in the organic solvent A and the lowest in the organic solvent C. On the other hand, when the solubility, the susceptibility, and the ease of expansion of the constituent components of the coating liquid L1 are comprehensively considered, the solubility of the constituent components of the coating liquid L1 is the highest and the organic solvent B is the organic solvent. C is the lowest.

Returning to Fig. 4, the pump 43 sucks the organic solvent L2 from the solvent source 41, and sends it to the nozzle 46 via the pipe 47, the valve 45, and the pipe 49. The pump 44 sucks the organic solvent L3 from the solvent source 42 and sends it to the nozzle 46 via the pipe 48, the valve 45, and the pipe 49. The valve 45 is a so-called mixing valve (2 fluid mixing valve) configured to mix the organic solvents L2, L3 sent from the pumps 43, 44.

The nozzle 46 is disposed above the wafer W such that the discharge port faces the surface Wa of the wafer W. The nozzle 46 is configured to be movable in the horizontal direction and the vertical direction by a driving unit (not shown). Specifically, the nozzle 46 moves linearly in a direction perpendicular to the rotation axis of the wafer W along the radial direction of the wafer W when the coating liquid is discharged. The nozzle 46 is raised to a position away from the holding portion 22 when the wafer W is held by the holding portion 22, and is lowered to the wafer when the wafer W is held by the holding portion 22 and the coating liquid is discharged. The approach position of W (holding portion 22). The nozzle 46 can discharge the organic solvent L2 or the organic solvent L3 which is mixed with the organic solvent L2, L3 in the valve 45 or one of the pumps 43, 44 to the surface Wa of the wafer W. In addition, the organic solvent L2, L3 can also be discharged from physically distinct nozzles by physically separated piping.

The piping 47 is connected to the solvent source 41, the pump 43, and the valve 45 in this order from the upstream side. The piping 48 is connected to the solvent source 42, the pump 44, and the valve 45 in this order from the upstream side. The piping 49 is connected to the valve 45 and the nozzle 46 in this order from the upstream side.

[Composition of controller]

As shown in FIG. 5, the controller 10 includes a reading unit M1, a memory unit M2, a processing unit M3, and an instruction unit M4 as functional modules. For the sake of convenience, the functional modules merely divide the functional area of the controller 10 into a plurality of modules, and do not mean that the hardware constituting the controller 10 is divided into such modules. Each functional module is not limited to being implemented by execution of a program, and may be implemented by a dedicated circuit (for example, a logic circuit) or an integrated circuit (ASIC: Application Specific Integrated Circuit) obtained by integrating the functions. By.

The reading unit M1 reads a program from a recording medium RM readable by a computer. The recording medium RM records a program for operating the respective units of the substrate processing system 1. The recording medium RM may be, for example, a semiconductor memory, an optical recording disk, a magnetic recording disk, or a magneto-optical recording sheet.

The memory unit M2 has various kinds of data. In the memory unit M2, for example, in addition to the program read from the recording medium RM in the reading unit M1, for example, various materials for supplying the coating liquid L1 and the organic solvents L2 and L3 to the wafer W are stored. (so-called treatment formula), A setting material or the like input by an operator by an external input device (not shown).

The processing unit M3 processes various materials. The processing unit M3 generates a coating unit U1 (for example, the rotation holding unit 20, the pumps 32, 43, 44, the valves 33, 45, the nozzles 34, 46, etc.) based on various materials stored in the memory unit M2. And the signal of the operation of the heat treatment unit U2.

The instruction unit M4 transmits a signal generated by the processing unit M3 to the coating unit U1 (for example, the rotation holding unit 20, the pumps 32, 43, 44, the valves 33, 45, the nozzles 34, 46, etc.) or the heat treatment unit U2. .

The hardware of the controller 10 is constituted by, for example, one or a plurality of computers for control. The controller 10 is configured as a hardware and has, for example, a circuit 10A as shown in FIG. Circuit 10A may also be constructed of circuit elements. The circuit 10A specifically includes a processor 10B, a memory 10C, a memory 10D, a driver 10E, and an input/output port 10F. The processor 10B executes a program in cooperation with at least one of the memory 10C and the memory 10D, and performs input and output of signals via the input/output port 10F, thereby constituting each of the above-described functional modules. The driver 10E is a circuit that drives various devices of the substrate processing system 1, respectively. The output port 10F is output between the driver 10E and various devices of the substrate processing system 1 (for example, the rotation holding unit 20, the pumps 32, 43, 44, the valves 33, 45, the nozzles 34, 46, etc.). In.

In the present embodiment, the substrate processing system 1 includes one controller 10, but may include a controller group (control unit) including a plurality of controllers 10. When the substrate processing system 1 is provided with a controller group, the above functions can be realized by one controller 10, respectively. The module may be implemented by a combination of two or more controllers 10. When the controller 10 is composed of a plurality of computers (circuits 10A), the above functional modules may be implemented by one computer (circuit 10A), or two or more computers (circuit 10A) Realized by a combination of ). The controller 10 can also have a plurality of processors 10B. In this case, the above-described functional modules may be implemented by one processor 10B, or may be realized by a combination of two or more processors 10B.

[Processing method of wafer]

Next, a method (substrate processing method) for processing the wafer W by supplying the coating liquid and the organic solvent to the wafer W will be described with reference to FIGS. 8 to 10 . First, the controller 10 controls each unit of the substrate processing system 1 to transport the wafer W from the carrier 11 to the coating unit U1 (step S11). Next, the controller 10 controls the rotation holding unit 20 to hold the wafer W in the holding portion 22 and rotate the wafer W by a predetermined number of rotations.

In this state, the controller 10 controls the pump 32, the valve 33, and the nozzle 34 (more specifically, the drive unit that drives the nozzle 34), and discharges the coating liquid L1 from the nozzle 34 to the surface Wa of the wafer W. A coating film F1 (uncured film) is formed on the surface Wa of the wafer W (step S12: first process; first process; see FIG. 9(a)). In this case, in order to form a photoresist film R having a film thickness of about 5 μm to 60 μm, for example, when the coating liquid L1 having a viscosity of, for example, 1000 cP or more and it is difficult to flow on the surface Wa of the wafer W is used, the wafer is used. The peripheral portion of the surface Wa of W generates a convex protrusion (so-called ridge) and the coating film F1 becomes extremely thick (see Fig. 9(b)).

Therefore, the controller 10 controls the pump 43, the valve 45, and the nozzle 46 (more specifically, the driving unit that drives the nozzle 46. The same applies hereinafter), and the peripheral portion of the wafer W from the nozzle 46 (the coating film F1) The peripheral portion) discharges the organic solvent L2, and dissolves the peripheral portion (the raised portion) of the coating film F1 (step S13: second item; second processing; see FIG. 9(b)). At this time, the posture of the nozzle 46 may be such that the discharge port of the nozzle 46 is vertically downward with respect to the surface Wa of the wafer W, or the discharge port of the nozzle 46 may be from the center portion of the wafer W toward the peripheral portion. Tilting downwards obliquely. In this case, the organic solvent L2 supplied to the peripheral edge portion of the coating film F1 is less likely to splash toward the center portion of the wafer W. Therefore, as a result of the processing of the wafer W, it is easy to ensure the in-plane uniformity of the formed photoresist film R.

In the process of dissolving the peripheral portion (the raised portion) of the coating film F1 by the organic solvent L2, the controller 10 first controls the nozzle 46, and discharges the organic solvent L2 from the nozzle 46 while making the nozzle 46 a predetermined number. The 1 speed moves from the periphery of the wafer W toward a position closer to the center portion than the peripheral edge. In this case, the organic solvent L2 becomes more difficult to splash around than when the organic solvent L2 is discharged at the position on the center side of the wafer W. This position on the center portion side of the wafer W corresponds to the position of the inner edge of the ridge portion, and may be, for example, a position 2 mm from the periphery of the wafer W toward the center portion. The first speed may be, for example, about 150 mm/sec. Further, at this time, the organic solvent L2 may be simultaneously supplied from the back side of the wafer W to the peripheral edge portion of the wafer W (so-called backside rinsing may be performed). In this case, it is possible to prevent the dissolution residue or the like of the coating film F1 from adhering to the back surface side of the wafer W. Therefore, when the wafer W is transported, the wafer The transport mechanism of W becomes difficult to be contaminated by the residue or the like.

Thereafter, the controller 10 controls the nozzle 46 to move the organic solvent L2 from the nozzle 46 while moving the nozzle 46 from the position on the center side of the wafer W toward the periphery of the wafer W at the second speed. In this case, it is more difficult to produce a situation in which the predetermined portion is particularly removed, and it is easier to ensure uniformity in the plane of the coating film F1, compared to when the organic solvent L2 is discharged while staying at the predetermined portion. Sex. The second speed may be slower than the first speed, and may be, for example, about 1 mm/sec. In this case, the removal of the ridge portion can be promoted in a state where it is difficult for the organic solvent L2 to flow to the center portion of the wafer W.

The controller 10 can also control the nozzle 46 to intermittently move the nozzle 46 from the position on the center side of the wafer W toward the periphery of the wafer W. Specifically, the controller 10 can control the nozzle 46 to discharge the organic solvent L2 from the nozzle 46 while sequentially performing the following steps: the nozzle 46 is spaced 2 mm from the periphery of the wafer W toward the center. After standing for 30 seconds, the nozzle 46 was moved at a speed of about 1 mm/sec to a second position 1.9 mm from the periphery of the wafer W toward the center, and the nozzle 46 was allowed to stand at the second position for 20 seconds; The speed of about 1 mm/sec is moved to a third position 1.8 mm from the periphery of the wafer W to the center side; the nozzle 46 is allowed to stand at the third position for 10 seconds; and the nozzle 46 is moved to a speed of about 1 mm/sec. a fourth position 1.5 mm apart from the periphery of the wafer W toward the center; The nozzle 46 is allowed to stand at the fourth position for 10 seconds; and the nozzle 46 is moved to the outside of the periphery of the wafer W at a speed of about 2 mm/sec.

Next, the controller 10 controls the rotation holding unit 20 to rotate the wafer W at a high speed in a short time (so-called short rotation) (step S14). For example, wafer W is rotated at 3500 rpm for 0.5 seconds. Thereby, the organic solvent L2 remaining on the surface of the coating film F1 and the residue dissolved by the organic solvent L2 can be discharged from the surface of the coating film F1.

Next, the controller 10 controls each unit of the substrate processing system 1 to transport the wafer W from the coating unit U1 to the heat treatment unit U2 (step S15). Next, the controller 10 controls the heat treatment unit U2 to heat the wafer W together with the coating film F1 to form a cured film F2 on which the coating film has been cured (step S16; third process; third process). At this time, the heat treatment may be performed for a predetermined time (about 180 seconds) at a predetermined temperature (for example, about 120 ° C). Alternatively, the first heat treatment (preheating) may be performed at a first temperature (for example, about 70 ° C) for a predetermined time (about 120 seconds), and the second heat treatment may be performed at a second temperature (for example, about 120 ° C). (Formal heating) Such an intermittent heat treatment for a predetermined time (about 180 seconds).

Next, the controller 10 controls each unit of the substrate processing system 1 to transport the wafer W from the heat treatment unit U2 to the coating unit U1 (step S17). Next, the controller 10 controls the rotation holding unit 20 to hold the wafer W in the holding portion 22 and rotate the wafer W by a predetermined number of rotations.

Secondly, the controller 10 controls the pump 43, the valve 45 and the spray The nozzle 46 discharges the organic solvent L3 from the nozzle 46 to the peripheral edge portion of the wafer W (the peripheral portion of the cured film F2), and dissolves the peripheral portion (the raised portion) of the cured film F2 (step S18: fourth engineering; fourth processing; Figure 10 (a)). At this time, the posture of the nozzle 46 may be such that the discharge port of the nozzle 46 is vertically downward with respect to the surface Wa of the wafer W, or the discharge port of the nozzle 46 may be from the center portion of the wafer W toward the peripheral portion. Tilting downwards obliquely. In this case, the organic solvent L3 supplied to the peripheral portion of the cured film F2 is less likely to splash toward the center portion of the wafer W. Therefore, as a result of the processing of the wafer W, it is easy to ensure the in-plane uniformity of the formed photoresist film R.

In the process of dissolving the peripheral portion (raised portion) of the cured film F2 by the organic solvent L3, the controller 10 controls the nozzle 46 to discharge the organic solvent L3 from the nozzle 46 while the nozzle 46 is at a predetermined speed (for example, 5 mm/sec or so) moves from the periphery of the wafer W toward a position closer to the center portion than the peripheral edge. The position on the center portion side of the wafer W corresponds to the position of the inner edge of the ridge portion, and may be, for example, a position a few mm from the periphery of the wafer W toward the center portion. Further, at this time, the organic solvent L3 may be simultaneously supplied from the back side of the wafer W to the peripheral portion of the wafer (so-called backside rinsing may be performed). In this case, it is possible to prevent the dissolved residue of the cured film F2 from adhering to the back side of the wafer W. Therefore, at the time of transport of the wafer W, the transfer mechanism of the wafer W is less likely to be contaminated by the residue or the like.

Next, the controller 10 controls the nozzle 46 to discharge the organic solvent L3 from the nozzle 46 while the nozzle 46 is stationary at a position corresponding to the inner edge of the ridge portion for a predetermined time (for example, about 5 seconds). Thereafter, control The controller 10 controls the nozzle 46 to discharge the organic solvent L3 from the nozzle 46 while the nozzle 46 is at a predetermined speed (for example, about 5 mm/sec) from the position on the center side of the wafer W toward the periphery of the wafer W. mobile. Thereby, the peripheral edge portion of the cured film F2 is removed from the surface Wa of the wafer W (see FIG. 10(b)).

By the above, the processing of the wafer W is completed, and the photoresist film R is formed on the surface Wa of the wafer W (see FIG. 10(b)).

In the above-described embodiment, the organic solvent L2 is discharged from the nozzle 46 and supplied to the peripheral portion of the coating film F1, and thereafter, the coating film F1 is cured by heating and the organic solvent L3 is applied to the cured film F2. The supply of the peripheral part. The coating film F1 (uncured film) before curing tends to be less soluble in an organic solvent than the coating film (cured film F2) after curing. Therefore, the organic solvent L2 does not remove all the peripheral portions of the coating film F1 (uncured film), but particularly removes the ridges in the peripheral portion. In this manner, before the formation of the cured film F2, the thickness of the peripheral portion of the coating film F1 is made similar to that of the other regions by removing the ridge portion from the coating film F1 in advance. Therefore, in the next step, the removal of the peripheral portion of the cured film F2 becomes easy, and the end surface of the cured film F2 after the removal of the peripheral portion becomes difficult to collapse. As a result, the shape of the photoresist film can be controlled while removing the ridge.

However, the ridge portion of the peripheral portion of the coating film F1 has a predetermined width. Therefore, when all the peripheral portions are removed together with the ridges by the organic solvents L2, L3, it is possible to waste the coating liquid and cause an increase in cost, and it is possible to change the area in the wafer W where electronic components can be manufactured or the like. It is narrow and causes a decrease in productivity. However, in the present embodiment, the raised portion of the coating film F1 (uncured film) is removed. Therefore, it is not necessary to remove all the peripheral portions in order to remove the ridges. Therefore, when the photoresist film R is formed on the surface Wa of the wafer W, cost reduction and productivity improvement can be achieved.

In the present embodiment, the solubility in the organic solvent L2 stored in the solvent source 41 with respect to the constituent component of the coating liquid of the coating liquid source 31 may be in the organic solvent L3 stored in the solvent source 42. The solubility with respect to the constituent components of the coating liquid is the same or higher. In this case, the coating film F1 (uncured film) which is more difficult to dissolve in the organic solvent than the cured film F2 can be effectively dissolved by the organic solvent L2.

Although the embodiments of the present disclosure have been described in detail above, various modifications may be made to the above-described embodiments within the scope of the gist of the invention.

10‧‧‧ Controller

20‧‧‧Rotary Holder

21‧‧‧Rotating Department

22‧‧‧ Keeping Department

23‧‧‧ shaft

30‧‧‧ Coating Liquid Supply Department

31‧‧‧ Coating liquid source

32‧‧‧ pump

33‧‧‧Valves

34‧‧‧Nozzles

35, 47, 48, 49‧‧‧ piping

40‧‧‧Solvent supply department

41‧‧‧ solvent source

42‧‧‧ solvent source

43‧‧‧ pump

44‧‧‧ pump

45‧‧‧ valve

46‧‧‧Nozzles

R‧‧‧Photoresist film

W‧‧‧ wafer

L1‧‧‧ coating liquid

L2‧‧‧Organic solvent

L3‧‧‧Organic solvent

U1‧‧‧ Coating unit

Wa‧‧‧ surface

Claims (9)

A substrate processing method includes: a first step of supplying a coating liquid onto a surface of a substrate to form a coating film; and a second project of discharging a first organic solvent from the first nozzle and supplying the coating film to the periphery of the coating film a portion that dissolves the raised portion of the peripheral portion into a convex shape and is flattened to a thickness similar to that of the other portions of the coating film; and the third project, after the second project, heats the coating film In the fourth step, the second organic solvent is discharged from the second nozzle and supplied to the peripheral portion of the cured film, and the peripheral portion is dissolved and removed from the substrate. The substrate processing method according to the first aspect of the invention, wherein the solubility of the constituent components of the coating film and the cured film in the first organic solvent is relative to the coating of the second organic solvent. The solubility of the constituent elements of the film and the cured film is the same or higher. The substrate processing method according to the first or second aspect of the invention, wherein the fourth project is a state in which the discharge port of the second nozzle is vertically downward with respect to a surface of the substrate, and the second The second organic solvent is discharged from the second nozzle while the nozzle of the second nozzle is ejected obliquely downward from the center portion of the substrate toward the peripheral portion. The substrate processing method of claim 1 or 2, wherein The second aspect of the invention includes moving the first nozzle from a peripheral edge of the substrate toward a position closer to a center portion than the peripheral edge at a first speed while discharging the first organic solvent from the first nozzle; While discharging the first organic solvent from the first nozzle, the first nozzle is moved from the position toward the periphery of the substrate at a second speed that is slower than the first speed. A substrate processing apparatus including: a coating liquid supply unit configured to supply a coating liquid to a surface of the substrate; and a solvent supply unit configured to supply the first and second organic solvents to a surface of the substrate; and a heating unit And the control unit, wherein the solvent supply unit includes a first nozzle that can discharge the first organic solvent, and a second nozzle that can discharge the second organic solvent, and the control unit executes In the first process, the coating liquid is supplied to the surface of the substrate to form a coating film by controlling the coating liquid supply unit, and the second processing is performed by controlling the solvent supply unit. (1) The organic solvent is discharged from the first nozzle and supplied to the peripheral edge portion of the coating film, and the convex portion having a convex shape in the peripheral portion is dissolved and leveled to the same extent as the other portions of the coating film. Thickness; third treatment, after the second treatment, by controlling the heating unit In the fourth method, the coating film is heated to form a cured film in which the coating film has been cured; and the fourth treatment is performed by controlling the solvent supply unit to discharge the second organic solvent from the second nozzle. To the peripheral portion of the cured film, the peripheral portion is dissolved and removed from the substrate. The substrate processing apparatus according to claim 5, wherein a solubility of a component of the first organic solvent with respect to the coating film and the cured film is relative to the coating of the second organic solvent. The solubility of the constituent elements of the film and the cured film is the same or higher. The substrate processing apparatus according to the fifth or sixth aspect of the invention, wherein the control unit is configured to cause the discharge port of the second nozzle to be vertically downward with respect to a surface of the substrate. The second organic solvent is discharged from the second nozzle, or the second organic solvent is made to be inclined obliquely downward from the center portion of the substrate toward the peripheral portion. Discharged from the second nozzle. The substrate processing apparatus according to claim 5, wherein the control unit performs the second processing while discharging the first organic solvent from the first nozzle. Moving the first nozzle from a peripheral edge of the substrate toward a position closer to a central portion than the peripheral edge; and While the first organic solvent is discharged from the first nozzle, the first nozzle is moved from the position toward the periphery of the substrate at a second speed that is slower than the first speed. A computer-readable recording medium recording a program for causing a substrate processing apparatus to perform the substrate processing method according to any one of claims 1 to 4.