Substrate processing method and substrate processing system

Abstract

To reduce the amount of residues on a substrate surface generated during development of a metal-containing coating film.SOLUTION: A method for treating a substrate includes the steps of developing a substrate on which a metal-containing coating film has been exposed to a predetermined pattern, cleaning the substrate after development, irradiating the cleaned substrate with ultraviolet light having a wavelength of 190 to 400 nm, and supplying a pattern cleaning solution containing an organic solvent to the substrate after the ultraviolet light irradiation step.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present disclosure relates to a substrate processing method and a substrate processing system. [Background technology]

[0002] Patent Document 1 discloses a coating and developing method characterized by including the steps of: applying a metal-containing resist to the surface of a substrate to form a resist film and exposing the resist film; a developing step of supplying a developer to the surface of the substrate to develop the resist film; and, prior to the developing step, forming a first protective film that prevents the peripheral portion of the substrate on which the resist film is not formed, at least the peripheral edge surface and the peripheral portion on the back side, from coming into contact with the developer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-047131 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology according to the present disclosure reduces the amount of residues on the substrate surface that are generated during development of a metal-containing coating film. [Means for solving the problem]

[0005] One aspect of the present disclosure is a method for treating a substrate, the method comprising: developing a substrate having a metal-containing coating film exposed to a predetermined pattern; cleaning the substrate after development; irradiating the cleaned substrate with ultraviolet light having a wavelength of 190 to 400 nm; and supplying a pattern cleaning solution containing an organic solvent to the substrate after the ultraviolet light irradiation step. In the developing step, a developer containing an organic solvent is supplied to the substrate, and in the cleaning step, a cleaning liquid containing an organic solvent is supplied to the substrate, the cleaning liquid having a lower solubility of the metal-containing coating film than the developer, and the pattern cleaning liquid having a higher solubility of the metal-containing coating film than the cleaning liquid. . [Effects of the Invention]

[0006] According to the present disclosure, it is possible to reduce the amount of residues on the substrate surface that are generated during the development process of a metal-containing coating film. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a plan view schematically illustrating an outline of a configuration of a substrate processing system according to an embodiment; [Figure 2] FIG. 2 is a front view schematically illustrating the configuration of the substrate processing system of FIG. [Figure 3] FIG. 2 is a rear view schematically illustrating the configuration of the substrate processing system of FIG. [Figure 4] 1 is a side cross-sectional view schematically illustrating an outline of a configuration of a developer supplying device according to an embodiment. [Figure 5] 1 is a side cross-sectional view schematically illustrating an outline of a configuration of a cleaning liquid supplying device according to an embodiment. [Figure 6] 1 is a side cross-sectional view schematically illustrating an outline of the configuration of a heat treatment apparatus according to an embodiment. [Figure 7] 1 is a side cross-sectional view schematically illustrating an outline of the configuration of an ultraviolet irradiation device according to an embodiment. [Figure 8] 1A to 1C are explanatory views showing the state of a metal-containing coating film on a substrate in a substrate processing method according to an embodiment. [Figure 9] FIG. 2 is an explanatory diagram showing the state of an exposed portion and an unexposed portion of a metal-containing coating film. DETAILED DESCRIPTION OF THE INVENTION

[0008] In the manufacturing process of semiconductor devices, a photolithography process is carried out, which includes forming a resist film by applying a resist to a semiconductor wafer (hereinafter referred to as "wafer"), exposing the resist film, and developing the exposed resist film to form a resist pattern. In recent years, the use of a resist solution containing a metal in the photolithography process has been considered in order to form finer resist patterns.

[0009] However, in the development process of a metal-containing resist film exposed to a predetermined pattern, the resist dissolved material that is not sufficiently dissolved in the developer tends to remain as residue on the wafer, and such residue causes pattern defects in the subsequent etching process. In particular, in the metal-containing resist film, a polymerization reaction between metal atoms and oxygen atoms tends to proceed little by little at the boundary between the unexposed area and the exposed area, and since this polymerization reaction area is hardly soluble in the developer, residue tends to remain on the wafer. With conventional development methods, it is difficult to remove such residue, making it difficult to mass-produce semiconductors using a metal-containing resist solution.

[0010] Therefore, the technology according to the present disclosure reduces the amount of residues on the substrate surface that are generated during the development process of the metal-containing coating film.

[0011] A substrate processing method and a substrate processing system for carrying out the substrate processing method according to the present embodiment will be described below with reference to the drawings. In this specification and the drawings, elements having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0012] Fig. 1 is a plan view schematically illustrating the configuration of a substrate processing system according to this embodiment, and Fig. 2 and Fig. 3 are a front view and a rear view respectively illustrating the internal configuration of the substrate processing system 1.

[0013] 1, the substrate processing system 1 has a cassette station 10 into which a cassette C containing a plurality of wafers W as substrates is loaded and unloaded, and a processing station 11 equipped with a plurality of various processing devices that perform predetermined processing on the wafers W. The substrate processing system 1 has a configuration in which the cassette station 10, the processing station 11, and an interface station 13 that transfers the wafers W between the processing station 11 and an exposure device 12 adjacent to the processing station 11 are integrally connected.

[0014] The cassette station 10 is provided with a cassette placement table 20. The cassette placement table 20 is provided with a plurality of cassette placement plates 21 on which the cassettes C are placed when the cassettes C are carried in or out of the substrate processing system 1.

[0015] The cassette station 10 is provided with a wafer transfer device 23 that is movable on a transfer path 22 extending in the X direction in Fig. 1. The wafer transfer device 23 is also movable in the vertical direction and around the vertical axis (the θ direction), and can transfer wafers W between the cassettes C on each cassette mounting plate 21 and a transfer device in the third block G3 of the processing station 11, which will be described later.

[0016] The processing station 11 is provided with multiple 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 of the processing station 11 (the negative X-direction side in FIG. 1), and a second block G2 is provided on the back side of the processing station 11 (the positive X-direction side in FIG. 1). Furthermore, a third block G3 is provided on the cassette station 10 side of the processing station 11 (the negative Y-direction side in FIG. 1), and a fourth block G4 is provided on the interface station 13 side of the processing station 11 (the positive Y-direction side in FIG. 1).

[0017] 2, the first block G1 is provided with a plurality of liquid processing devices, such as a developer supply device 30, a resist coating device 31, and a cleaning liquid supply device 32. The developer supply device 30 performs a development process on the wafer W. The resist coating device 31 supplies a resist liquid containing a metal (e.g., Sn) as a metal-containing processing liquid to the wafer W to form a metal-containing resist film as a metal-containing coating film. The cleaning liquid supply device 32 supplies a cleaning liquid containing an organic solvent to the wafer W to clean the wafer W. The number and arrangement of the developer supply devices 30, resist coating devices 31, and cleaning liquid supply devices 32 can be selected as desired.

[0018] In these developing solution supply device 30, resist coating device 31, and cleaning solution supply device 32, for example, spin coating using a predetermined processing solution or coating solution is performed on the wafer W. In spin coating, for example, the processing solution or coating solution is ejected onto the wafer W from a nozzle, and the wafer W is rotated to spread the processing solution or coating solution over the surface of the wafer W.

[0019] 3, the second block G2 has a heat treatment device 40, a peripheral exposure device 41, and an ultraviolet irradiation device 42 arranged vertically and horizontally. The heat treatment device 40 performs heat treatment such as heating and cooling of the wafer W. The peripheral exposure device 41 exposes the peripheral portion of the wafer W. The ultraviolet irradiation device 42 irradiates ultraviolet light onto the wafer W. The number and arrangement of the heat treatment devices 40, peripheral exposure devices 41, and ultraviolet irradiation devices 42 can be selected arbitrarily.

[0020] For example, in the third block G3, a plurality of transfer devices 50, 51, 52, 53, 54, 55, 56 are provided in this order from the bottom up, and in the fourth block G4, a plurality of transfer devices 60, 61, 62 are provided in this order from the bottom up.

[0021] 1 and 3, 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 wafer transfer device 70 is arranged.

[0022] Each wafer transfer device 70 has a transfer arm 70a that can move freely in, for example, the Y direction, the X direction, the θ direction, and the up and down direction. A plurality of wafer transfer devices 70 are arranged one above the other, and each wafer transfer device 70 moves within the wafer transfer area D and can transfer the wafer W to a predetermined device at approximately the same height in each of blocks G1 to G4, for example.

[0023] In addition, the wafer transfer region D is provided with a shuttle transfer device 80 that transfers the wafer W linearly between the third block G3 and the fourth block G4.

[0024] Shuttle transfer device 80 is movable linearly, for example, in the Y direction in Fig. 3. Shuttle transfer device 80 moves in the Y direction while supporting a wafer W, and can transfer the wafer W between delivery device 52 in the third block G3 and delivery device 62 in the fourth block G4.

[0025] 1, a wafer transfer device 90 is provided adjacent to the third block G3 on the positive side in the X direction. The wafer transfer device 90 has a transfer arm 90a that is movable in, for example, the X direction, the θ direction, and the up-and-down direction. The wafer transfer device 90 moves up and down while supporting a wafer W, and can transfer the wafer W to each delivery device in the third block G3.

[0026] The interface station 13 is provided with a wafer transfer device 100 and a delivery device 101. The wafer transfer device 100 has a transfer arm 100a that is movable in, for example, the Y direction, the θ direction, and the up and down direction. The wafer transfer device 100 supports a wafer W on, for example, the transfer arm 100a, and can transfer the wafer W between each delivery device in the fourth block G4, the delivery device 101, and the exposure device 12.

[0027] The substrate processing system 1 described above is provided with a control unit 200. The control unit 200 is configured by a computer equipped with, for example, a CPU, a memory, etc., and has a program storage unit (not shown). The program storage unit stores programs for controlling various processes in the substrate processing system 1. The programs may be recorded on a computer-readable storage medium H and installed from the storage medium H into the control unit 200. Some or all of the programs may be realized by dedicated hardware (circuit board). The storage medium H may be a temporary storage medium or a non-temporary storage medium.

[0028] Next, various apparatuses for carrying out the substrate processing method according to this embodiment will be individually and specifically described.

[0029] <Developer supply device> 4 is a side cross-sectional view schematically illustrating the configuration of a developer supplying apparatus 30 according to this embodiment. The developer supplying apparatus 30 has a processing vessel 110, and a loading / unloading port (not shown) for a wafer W is formed on the side of the processing vessel 110. The processing vessel 110 contains a spin chuck 111 as a substrate holding unit. The spin chuck 111 holds a wafer W as a substrate horizontally. The spin chuck 111 is connected to a rotating unit 112 that can be raised and lowered, and the rotating unit 112 is connected to a rotation driving unit 113 formed by a motor or the like. Therefore, the held wafer W can be rotated by driving the rotation driving unit 113.

[0030] A filter device 114 is provided on the ceiling of the processing vessel 110 , and a downflow of purified air is formed in the processing vessel 110 via an air supply part 115 .

[0031] A cup 116 is disposed outside the spin chuck 111 to prevent the scattering of the developing solution, cleaning solution, and mists thereof to the surrounding area. A drain pipe 117 and an exhaust pipe 118 are provided at the bottom of the cup 116. The exhaust pipe 118 is connected to an exhaust device 119 such as an exhaust pump.

[0032] A developer nozzle 120 is disposed in the processing vessel 110 as a developer supply unit that discharges developer toward the surface of the wafer W. The developer nozzle 120 is mounted on a nozzle support 121, such as an arm, which can be moved up and down by a drive mechanism (not shown) as indicated by a dashed reciprocating arrow A in the drawing, and can also be moved horizontally as indicated by a dashed reciprocating arrow B. A developer is supplied to the developer nozzle 120 from a developer supply source 123 via a supply pipe 122.

[0033] Also disposed within the processing vessel 110 is a cleaning liquid nozzle 130 serving as a cleaning liquid supply unit that discharges a cleaning liquid toward the surface of the wafer W. The cleaning liquid nozzle 130 is mounted on a nozzle support 131, such as an arm, which can be moved up and down by a drive mechanism (not shown) as indicated by a reciprocating arrow C shown by a dashed line in the figure, and can also be moved horizontally as indicated by a reciprocating arrow D shown by a dashed line. A cleaning liquid is supplied to the cleaning liquid nozzle 130 from a cleaning liquid supply source 133 via a supply pipe 132.

[0034] According to the developer supplying apparatus 30 of this embodiment, the developer or cleaning liquid is supplied to the center of the wafer W while rotating the wafer W, thereby spreading the developer or cleaning liquid over the entire wafer W. However, the method of supplying the developer or cleaning liquid is not particularly limited as long as it is a method capable of supplying the developer or cleaning liquid to the surface of the wafer W, and therefore the configuration of the developer supplying apparatus 30 is not limited to the configuration described in this embodiment. The configuration of the apparatus can be changed as appropriate depending on the development method employed, such as puddle development or spray development.

[0035] <Cleaning liquid supply device> 5 is a side cross-sectional view that schematically illustrates the overall configuration of a cleaning liquid supply apparatus 32 according to this embodiment. The cleaning liquid supply apparatus 32 has a housing 140, and a loading / unloading port (not shown) for a wafer W is formed on a side surface of the housing 140. The housing 140 contains a spin chuck 141 as a substrate holder. The spin chuck 141 horizontally holds a wafer W as a substrate. The spin chuck 141 is connected to a rotating unit 142 that can be raised and lowered, and the rotating unit 142 is connected to a rotation driving unit 143 that is formed by a motor or the like. Therefore, the held wafer W can be rotated by driving the rotation driving unit 143.

[0036] A filter device 144 is provided on the ceiling of the housing 140 , and a downflow of purified air is formed inside the housing 140 via an air intake section 145 .

[0037] A cup 146 is disposed outside the spin chuck 141 to prevent the scattering of the cleaning liquid and its mist to the surrounding area. A drain pipe 147 and an exhaust pipe 148 are provided at the bottom of the cup 146. The exhaust pipe 148 is connected to an exhaust device 149 such as an exhaust pump.

[0038] A cleaning liquid nozzle 150 is disposed within the housing 140 as a cleaning liquid supply unit that discharges a cleaning liquid (a pattern cleaning liquid, which will be described later) toward the surface of the wafer W. The cleaning liquid nozzle 150 is mounted on a nozzle support unit 151, such as an arm, which can be moved up and down by a drive mechanism (not shown) as indicated by a reciprocating arrow E shown by a dashed line in the figure, and can also be moved horizontally as indicated by a reciprocating arrow F shown by a dashed line. A cleaning liquid is supplied to the cleaning liquid nozzle 150 from a cleaning liquid supply source 153 via a supply pipe 152.

[0039] According to the cleaning liquid supply device 32 of this embodiment, the cleaning liquid is supplied to the center of the wafer W while rotating the wafer W, thereby making it possible to spread the cleaning liquid over the entire wafer W. However, the method of supplying the cleaning liquid is not particularly limited as long as it is a method capable of supplying the cleaning liquid to the surface of the wafer W, and therefore the configuration of the cleaning liquid supply device 32 is not limited to the configuration described in this embodiment.

[0040] <Heat treatment equipment> 6 is a side cross-sectional view schematically illustrating the configuration of a heat treatment apparatus 40 according to this embodiment. The heat treatment apparatus 40 has a processing container 160, and a loading / unloading port (not shown) for a wafer W is formed on a side surface of the processing container 160. A mounting table 161 is provided in the processing container 160 as a substrate holder for placing the wafer W thereon. A heater 162 is provided in the mounting table 161 as a heating unit for the wafer W. The mounting table 161 has a plurality of through holes 163 formed therein. Lift pins 164a that move up and down within the through holes 163 are provided on a lift pin support 164. The lift pin support 164 is raised and lowered by a lift mechanism 165.

[0041] The heat treatment apparatus 40 is not limited to the configuration described in this embodiment, but may have any configuration capable of heating the wafer W.

[0042] <Ultraviolet irradiation device> 7 is a side cross-sectional view schematically showing the outline of the configuration of an ultraviolet irradiation device 42 according to this embodiment. The ultraviolet irradiation device 42 has a housing 170, and a loading / unloading port (not shown) for a wafer W is formed on a side surface of the housing 170. A mounting table 171 is provided inside the housing 170 as a substrate holder for placing the wafer W thereon. The mounting table 171 has through holes 172 formed in multiple locations. Lift pins 173a that move up and down within these through holes 172 are provided on a lift pin support portion 173. The lift pin support portion 173 is raised and lowered by a lift mechanism 174.

[0043] Above the mounting table 171, a UV lamp 175 is disposed as an ultraviolet irradiator that irradiates the surface of the wafer W mounted on the mounting table 171 with ultraviolet rays. In this embodiment, the UV lamp 175 radially irradiates ultraviolet rays having a wavelength of 190 to 400 nm. The ultraviolet irradiator 42 is not limited to the configuration described in this embodiment, and may have any configuration that can irradiate the wafer W with ultraviolet rays having a wavelength of 190 to 400 nm. For example, a KrF exposure device with a wavelength of 248 nm is used as the ultraviolet irradiator 42.

[0044] The substrate processing system 1 according to this embodiment is configured as described above. Next, a substrate processing method for the wafer W in this substrate processing system 1 will be described.

[0045] When performing the development process on the wafer W, first, in the resist coating device 31, a metal-containing resist film R is formed on the surface of the wafer W (FIG. 8(a)).

[0046] Thereafter, the wafer W undergoes edge exposure processing in the edge exposure device 41, exposure processing in the exposure device 12, and PEB processing in the heat treatment device 40, resulting in a state in which an unexposed resist film R1 and an exposed resist film R2 are present on the surface of the wafer W (FIG. 8(b)). At this time, the resist film R2 in the exposed portion is in a state in which the polymerization reaction has progressed overall, and the resist film R1 in the unexposed portion is in a state in which the polymerization reaction has not progressed overall.

[0047] Due to the characteristics of the exposure machine, the exposure process of the resist film R is performed under conditions in which the exposure intensity changes periodically, as shown in Figure 9. More specifically, the exposure intensity is low in the horizontal center of the unexposed resist film R1, so that the polymerization reaction does not proceed, whereas the exposure intensity is higher near the boundary with the exposed resist film R2 than in the central portion. Therefore, in the unexposed resist film R1 near the boundary with the exposed resist film R2, there is an area A1 in which the polymerization reaction has progressed, even though it is an unexposed area.

[0048] Furthermore, the exposure intensity is high enough in the horizontal center of the exposed resist film R2 to allow the polymerization reaction to proceed sufficiently, while the exposure intensity is lower near the boundary with the unexposed resist film R1 than in the center. Therefore, in the exposed resist film R2 near the boundary with the unexposed resist film R1, there is a region A2 where the polymerization reaction has progressed less than in the center of the exposed resist film R2.

[0049] Next, the wafer W exposed to a predetermined pattern is transferred to a developer supplying device 30, where a developer is supplied to the surface of the wafer W. The developer supplied here contains an organic solvent. This dissolves the resist film R1 in the unexposed areas formed on the surface of the wafer W (FIG. 8(c)). There are no particular limitations on the type of developer containing an organic solvent, as long as it is a processing liquid that does not dissolve the resist film R2 in the exposed areas. The developer may also be a mixture of two or more organic solvents. For example, 2-heptanone or a mixture of PGMEA (propylene glycol monomethyl ether acetate) and acetic acid may be used as the developer.

[0050] Although most of the resist dissolved in the developer is removed from the surface of the wafer W together with the drained developer, dissolved resist material that is not completely dissolved in the developer may remain as residue on the surface of the wafer W. In particular, the unexposed resist film R1 shown in FIG. 8(b) has a region A1 where the polymerization reaction has progressed, and this region A1 is less soluble in organic solvents than other regions of the unexposed resist film R1. For this reason, the resist film R1 does not completely dissolve in this region A1, and dissolved resist material is likely to remain on the surface of the wafer W.

[0051] Next, a cleaning liquid is supplied to the wafer W on which the dissolved resist remains. The cleaning liquid supplied here contains an organic solvent, just like the developer. Therefore, when the dissolved resist comes into contact with the cleaning liquid, the dissolved resist begins to dissolve. Then, the dissolved resist that has completely dissolved in the cleaning liquid is removed from the surface of the wafer W together with the waste cleaning liquid (FIG. 8(d)). This reduces the amount of dissolved resist remaining as residue on the surface of the wafer W.

[0052] In the above-described process of supplying a cleaning liquid to the wafer W, a processing liquid having a lower solubility for the metal-containing resist film R than the developer is used as the cleaning liquid to avoid dissolution of the pattern. Here, the "solubility of the metal-containing resist film R" of the developer or cleaning liquid is an index indicating the ease with which the metal-containing resist film R dissolves in the developer or cleaning liquid. For example, when two types of processing liquids are supplied in equal amounts to the resist film R, the processing liquid that dissolves the smaller amount of resist film R (volume reduction) per unit time is the processing liquid that has a relatively smaller solubility for the metal-containing resist film R.

[0053] Generally, a developer has a solubility sufficient to prevent the resist film R2 from dissolving in the exposed area. However, if a cleaning solution with a higher solubility than the developer is used, the resist film R2 in the exposed area will dissolve, potentially causing the pattern shape to collapse. Furthermore, in the region A2 in the exposed resist film R2, the polymerization reaction has progressed less than in other regions of the exposed resist film R2, making the region A2 more soluble in organic solvents. Therefore, if the solubility of the resist film R is the same in the cleaning solution and the developer, the region A2 will dissolve slightly, potentially causing the pattern shape to collapse. Therefore, by using a processing solution with a lower solubility for the resist film R than the developer as the cleaning solution, the resist soluble material remaining on the surface of the wafer W can be dissolved without causing the pattern to collapse.

[0054] The type of cleaning liquid containing an organic solvent is not particularly limited as long as it is a processing liquid that dissolves the resist film R less than the developer. The cleaning liquid may also be a mixture of two or more organic solvents. For example, when the developer is 2-heptanone, processing liquids such as MIBC (methyl isobutyl carbinol) and PGMEA (propylene glycol monomethyl ether acetate) may be used as the cleaning liquid. For example, when the developer is a mixture of PGMEA and acetic acid, processing liquids such as 2-heptanone, MIBC, PGMEA, PGME (propylene glycol monomethyl ether), a mixture of PGMEA and PGME, and n-butyl acetate (nBA) may be used as the cleaning liquid. In this embodiment, the developer supply device 30 is provided with the cleaning liquid nozzle 130, so the developer supply device 30 supplies the cleaning liquid following the supply of the developer. However, the wafer W may be transported to the cleaning liquid supply device 32, for example, and the cleaning liquid may be supplied therefrom.

[0055] According to the substrate processing method of this embodiment, by performing the above-mentioned steps of supplying a developer to the wafer W and supplying a cleaning liquid to the wafer W, the amount of dissolved resist remaining as residue on the surface of the wafer W can be reduced, and a predetermined resist pattern can be formed on the wafer W.

[0056] Depending on the types and processing conditions of the metal-containing resist solution, developer, cleaning solution, etc., the dissolved resist remaining on the surface of the wafer W may be removed to an extent that satisfies the required quality at the stage when the step of supplying the cleaning solution to the wafer W shown in Fig. 8(d) is completed. In that case, the series of development steps for forming a resist pattern is completed at the step of supplying the cleaning solution to the wafer W shown in Fig. 8(d).

[0057] On the other hand, in order to further reduce the amount of residue remaining on the surface of the wafer W after the step of supplying the cleaning liquid to the wafer W, the following steps are carried out as necessary.

[0058] First, the wafer W cleaned with a cleaning solution is transferred to the ultraviolet irradiation device 42, where the surface of the wafer W is irradiated with ultraviolet light having a wavelength of 190 to 400 nm. In this process, for example, KrF exposure with a wavelength of 248 nm is performed. No mask is used during ultraviolet irradiation, and the entire wafer W is uniformly irradiated with ultraviolet light. This further advances the exposure reaction of the entire resist film R2 in the exposed area, and the exposure reaction also advances in the region A2 of the resist film R2 where the exposure reaction has relatively not progressed, similar to the other regions (FIG. 8(e)). Note that when the wavelength of ultraviolet light is less than 190 nm, irradiation with ultraviolet light causes a reaction in which the C-O bond of the resist film R2 is broken, but no exposure reaction of the resist film R2 occurs. Furthermore, although ultraviolet light is irradiated by the ultraviolet irradiation device 42 in this embodiment, it may also be performed by, for example, the exposure device 12.

[0059] Next, the wafer W irradiated with ultraviolet rays is transferred to the heat treatment device 40 and heated. This further promotes the polymerization reaction of the resist film R2, the entire film of which has been sufficiently exposed, and the resist film R2 hardens and transforms into a strong resist film R3 (FIG. 8(f)). In this embodiment, the wafer W is heated in the heat treatment device 40 after ultraviolet irradiation. However, if the ultraviolet irradiation device 42 has a wafer W heating mechanism, the wafer W may be heated in the ultraviolet irradiation device. Furthermore, if ultraviolet irradiation and wafer W heating are possible in the same module, the wafer W may be heated during or after ultraviolet irradiation.

[0060] Next, the heated wafer W is transferred to the cleaning liquid supply device 32, and a cleaning liquid is supplied onto the surface of the wafer W. Note that the "cleaning liquid" supplied here will be referred to as a "pattern cleaning liquid" in the following description for convenience's sake to distinguish it from the cleaning liquid supplied in the step shown in Figure 8(d). The pattern cleaning liquid contains an organic solvent, and when the pattern cleaning liquid comes into contact with the dissolved resist material remaining on the surface of the wafer W, the dissolved resist material dissolves (Figure 8(g)).

[0061] Furthermore, since the resist film R3 hardened through UV irradiation and heat treatment is less soluble in organic solvents, it is possible to use, as the pattern cleaning liquid, a processing liquid that has a higher solubility for the resist film R than the cleaning liquid used before UV irradiation. Therefore, it is possible to dissolve the dissolved resist material that was not completely removed in the cleaning process of the wafer W shown in FIG. 8(d). The dissolved resist material dissolved in the pattern cleaning liquid is removed from the surface of the wafer W together with the drained pattern cleaning liquid. This makes it possible to further reduce the amount of dissolved resist material remaining as residue on the surface of the wafer W.

[0062] The pattern cleaning liquid containing an organic solvent is not particularly limited as long as it is a processing liquid that does not dissolve the cured resist film R3. The pattern cleaning liquid may also be a mixture of two or more organic solvents. For example, an alkaline processing liquid such as a processing liquid containing TMAH (tetramethylammonium hydroxide) may be used as the pattern cleaning liquid. As an example, a TMAH aqueous solution with a mass percent concentration of 2.38% may be used as the pattern cleaning liquid. Furthermore, a processing liquid containing an organic acid such as acetic acid, formic acid, or citric acid may also be used as the pattern cleaning liquid. Furthermore, since the cured resist film R3 is less soluble in organic solvents than the resist film R2 before UV irradiation, it is also possible to select a processing liquid that has a higher solubility for the resist film R than the developer as the pattern cleaning liquid.

[0063] In this embodiment, the supply of the pattern cleaning liquid is performed by the cleaning liquid supply device 32, but if the developer supply device 30 has the function of supplying the pattern cleaning liquid, the supply of the pattern cleaning liquid to the wafer W may be performed by the developer supply device 30.

[0064] After the wafer W has been cleaned with the pattern cleaning liquid, it is cleaned with pure water and dried, completing a series of development steps.

[0065] As described above, by irradiating the wafer W with ultraviolet light having a wavelength of 190 to 400 nm after supplying the developer, then heating the wafer W, and then supplying the pattern cleaning liquid to the wafer W, the amount of dissolved resist remaining as residue on the surface of the wafer W can be further reduced.

[0066] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

[0067] The substrate processing method according to the present disclosure can also be applied to processing substrates other than semiconductor wafers, such as FPD (flat panel display) substrates. [Explanation of symbols]

[0068] 1. Substrate Processing System 30 Developer supply device 32 Cleaning liquid supply device 200 control section R Metal-containing resist film W wafer

Claims

1. A method for processing a substrate, comprising: developing the substrate on which the metal-containing coating film has been exposed in a predetermined pattern; cleaning the substrate after development; irradiating the cleaned substrate with ultraviolet light having a wavelength of 190 to 400 nm; a step of supplying a pattern cleaning liquid containing an organic solvent to the substrate after the step of irradiating with ultraviolet light, supplying a developer containing an organic solvent to the substrate in the developing step; supplying a cleaning liquid containing an organic solvent to the substrate in the cleaning step; the cleaning solution has a lower solubility for the metal-containing coating film than the developer, The substrate processing method, wherein the pattern cleaning solution has a higher solubility for the metal-containing coating film than the cleaning solution.

2. heating the substrate during or after the irradiation with ultraviolet light; 2. The substrate processing method according to claim 1, wherein the step of supplying the pattern cleaning liquid is performed after the step of heating the substrate.

3. 3. The substrate processing method according to claim 1, wherein at least one of the developing solution and the cleaning solution is a mixed solution of two or more kinds of organic solvents.

4. 3. The substrate processing method according to claim 1, wherein the developer is 2-heptanone.

5. 5. The substrate processing method according to claim 4, wherein the cleaning liquid is methyl isobutyl carbinol or propylene glycol monomethyl ether acetate.

6. 3. The substrate processing method according to claim 1, wherein the developer is a mixture of propylene glycol monomethyl ether acetate and acetic acid.

7. 7. The substrate processing method according to claim 6, wherein the cleaning liquid is any one processing liquid selected from the group consisting of 2-heptanone, methyl isobutyl carbinol, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, a mixed liquid of propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether, and n-butyl acetate.

8. 8. The substrate processing method according to claim 1, wherein the pattern cleaning liquid is an alkaline processing liquid or a processing liquid containing an organic acid.

9. A substrate processing system for processing a substrate, a developing unit that develops the substrate; a cleaning unit that cleans the substrate; a control unit that controls operations of the developing unit and the cleaning unit; an ultraviolet irradiation unit that irradiates the substrate with ultraviolet light having a wavelength of 190 to 400 nm; a pattern cleaning liquid supply unit that supplies a pattern cleaning liquid to the substrate, The control unit developing the substrate on which the metal-containing coating film has been exposed in a predetermined pattern; cleaning the substrate after development; irradiating the cleaned substrate with ultraviolet light having a wavelength of 190 to 400 nm; a step of supplying a pattern cleaning liquid containing an organic solvent to the substrate after the step of irradiating with ultraviolet light, the control unit executes control to supply a developing solution containing an organic solvent to the substrate in the developing step, and to supply a cleaning solution containing an organic solvent to the substrate in the cleaning step; the cleaning solution has a lower solubility for the metal-containing coating film than the developer, The substrate processing system, wherein the pattern cleaning solution has a higher solubility for the metal-containing coating film than the cleaning solution.

10. a heating unit that heats the substrate, 10. The substrate processing system according to claim 9, wherein the control unit is configured to perform a step of heating the substrate during or after the irradiation with ultraviolet rays, and to perform a step of supplying the pattern cleaning liquid after the step of heating the substrate.

11. 11. The substrate processing system according to claim 9, wherein at least one of the developing solution and the cleaning solution is a mixed solution of two or more kinds of organic solvents.

12. 11. The substrate processing system according to claim 9, wherein the developer is 2-heptanone.

13. 13. The substrate processing system of claim 12, wherein the cleaning liquid is methyl isobutyl carbinol or propylene glycol monomethyl ether acetate.

14. 11. The substrate processing system according to claim 9, wherein the developer is a mixture of propylene glycol monomethyl ether acetate and acetic acid.

15. 15. The substrate processing system according to claim 14, wherein the cleaning liquid is any one processing liquid selected from the group consisting of 2-heptanone, methyl isobutyl carbinol, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, a mixed liquid of propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether, and n-butyl acetate.

16. 16. The substrate processing system according to claim 9, wherein the pattern cleaning liquid is an alkaline processing liquid or a processing liquid containing an organic acid.

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