Light irradiation device and substrate processing device

Abstract

To provide a light irradiation device and a substrate processing apparatus capable of forming resist patterns with excellent heat resistance in a short time.SOLUTION: One aspect of the present invention is a light irradiation device. The light irradiation device comprises a light irradiation unit that irradiates one or both ultraviolet and visible light rays to a substrate. The light irradiation device comprises a control unit that controls the light irradiation unit. The control unit performs the first irradiation control in which the substrate is irradiated with light that is attenuated in the region of wavelengths below 330 nm among ultraviolet and visible light. After the first irradiation control, the control unit performs the second irradiation control in which the substrate is irradiated with light containing both UV and visible light.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a light irradiation device and a substrate processing device.

Background Art

[0002] A method is known in which a resist film is formed on a substrate using a resist material such as a resin, the resist film is exposed, and a resist pattern having a predetermined shape is formed on the resist film by development. For example, Patent Document 1 discloses a step (1) of forming a prepattern by exposing a resist film formed on a substrate using a resist composition and then patterning by development, and a step (2) of irradiating the prepattern with one or both of ultraviolet light and visible light to cure the prepattern. Step (2) includes an operation of irradiating the prepattern with light having a wavelength of less than 300 nm cut out of ultraviolet light and visible light.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, there is room for improvement in forming a resist pattern having excellent heat resistance in a short time.

[0005] In view of the above circumstances, an object of the present invention is to provide a light irradiation device and a substrate processing device capable of forming a resist pattern having excellent heat resistance in a short time.

Means for Solving the Problems

[0006] One aspect of the present invention is a substrate Expose and develop the upper resist film A light irradiation device for curing a formed prepattern. The light irradiation device is provided with a chamber that forms an accommodation space capable of accommodating a substrate and adjusts the accommodation space to a predetermined gas atmosphere. The light irradiation device includes a control unit. The light irradiation device includes a light source that irradiates light. The light irradiation device is detachable from and attachable to the light source, and includes a first optical filter that attenuates light in a first region for curing the surface layer portion of the prepattern. The control unit irradiates the substrate with light from the light source with the first optical filter attached to the light source. In a gas atmosphere light Directly irradiate to suppress the hardening of the surface layer portion of the prepattern and executes first irradiation control. After the first irradiation control, the control unit irradiates the substrate with light from the light source with the first optical filter detached from the light source. In a gas atmosphere light Directly and executes second irradiation control. One aspect of the present invention is a light irradiation device for curing a prepattern formed on a substrate. Expose and develop the resist film on top The light irradiation device includes a control unit. The light irradiation device includes a light irradiation unit that includes a light source that irradiates light. The light irradiation unit includes, as a light source, a first light source that irradiates light with attenuation of light in a first region for curing the surface layer portion of the prepattern. The light irradiation unit includes, as a light source, a second light source that irradiates light including all or part of the light in the first region. The control unit irradiates the substrate with light from the first light source and executes first irradiation control. After the first irradiation control, the control unit irradiates the substrate with light from the second light source and executes second irradiation control. The light irradiation device is provided with a chamber that forms an accommodation space capable of accommodating a substrate and adjusts the accommodation space to a predetermined gas atmosphere. One aspect of the present invention is a substrate processing apparatus. The substrate processing apparatus includes a coating device that coats a resist on a substrate to form a resist film. The substrate processing apparatus includes an exposure device that exposes the resist film. The substrate processing apparatus includes a developing device that develops the exposed resist film to form a prepattern. The substrate processing apparatus includes the light irradiation device of the above-described aspect. In a gas atmosphere light Directly irradiate to suppress the hardening of the surface layer portion of the prepattern and executes first irradiation control. After the first irradiation control, the control unit irradiates the substrate with light from the second light source and executes second irradiation control. In a gas atmosphere light Directly and executes second irradiation control.

[0007] One aspect of the present invention is a substrate processing apparatus. The substrate processing apparatus includes a coating device that coats a resist on a substrate to form a resist film. The substrate processing apparatus includes an exposure device that exposes the resist film. The substrate processing apparatus includes a developing device that develops the exposed resist film to form a prepattern. The substrate processing apparatus includes the light irradiation device of the above-described aspect.

Advantages of the Invention

[0008] According to the present invention, it is possible to provide a resist pattern forming method, a light irradiation device, and a substrate processing apparatus capable of forming a resist pattern excellent in heat resistance in a short time.

Brief Description of the Drawings

[0009]

Figure 1

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BEST MODE FOR CARRYING OUT THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, an XYZ orthogonal coordinate system is set, and the positional relationship of each member will be described with reference to this XYZ orthogonal coordinate system. A predetermined direction in the horizontal plane is defined as the X direction, a direction orthogonal to the X direction in the horizontal plane is defined as the Y direction, and a direction orthogonal to each of the X direction and the Y direction (i.e., the vertical direction) is defined as the Z direction.

[0011] <First Embodiment> <Method for forming resist pattern> The method for forming a resist pattern according to the first embodiment includes a step (1) of exposing a resist film formed on a substrate using a resist composition and then patterning by development to form a prepattern, and a step (2) of irradiating one or both of ultraviolet rays and visible rays to cure the prepattern. Details of the resist composition will be described later.

[0012] <Step (1)> In step (1), after exposing a resist film formed on a support (substrate) using a resist composition, patterning is performed by development to form a prepattern. In the present invention, the "prepattern" refers to the resist pattern formed in step (1). The prepattern can be formed, for example, as follows.

[0013] First, the resist composition is applied onto the support using a spinner or the like, and baking (post - apply bake (PAB)) treatment is performed, for example, under temperature conditions of 90 to 130°C, preferably for 40 to 120 seconds, more preferably for 60 to 90 seconds to form a resist film. At this time, the thickness of the resist film is preferably about 0.5 to 2.5 μm, more preferably about 1.0 to 2.0 μm.

[0014] Next, selective exposure is performed on the resist film using a light source that emits ultraviolet rays, such as a low - pressure mercury lamp, a high - pressure mercury lamp, an ultra - high - pressure mercury lamp, a xenon lamp, etc., through a mask (mask pattern) on which a predetermined pattern is formed.

[0015] Next, the exposed resist film is developed. The development process is performed, for example, by filling an alkaline aqueous solution such as a 1 to 10 mass% aqueous solution of tetramethylammonium hydroxide (TMAH) from one end of the support to the other end, or by spreading it over the entire surface of the support from a developing liquid dropping nozzle installed above the vicinity of the center. Then, development is carried out by standing still for about 50 to 90 seconds.

[0016] After the development process, a rinsing process is preferably performed. The rinsing process is carried out, for example, by washing the developer remaining on the prepattern surface with a rinsing liquid (such as pure water or an organic solvent). Further, after the development process or after the rinsing process, a heating (post-bake) process may be performed. The prepattern can be obtained in the above manner.

[0017] The support is not particularly limited, and conventionally known ones can be used. For example, substrates for electronic components and those with a predetermined wiring pattern formed thereon can be exemplified. More specifically, metal substrates such as silicon wafers, copper, chromium, iron, and aluminum, and glass substrates can be mentioned. As materials for the wiring pattern, for example, copper, aluminum, nickel, gold, etc. can be used.

[0018] In addition, as the support, a substrate having an inorganic and / or organic film provided thereon as described above may be used. Examples of the inorganic film include an inorganic anti-reflection film (inorganic BARC). Examples of the organic film include an organic anti-reflection film (organic BARC) and an organic film such as the lower organic film in the multilayer resist method. Here, the multilayer resist method is a method in which at least one organic film (lower organic film) and at least one resist film (upper resist film) are provided on a substrate, and patterning of the lower organic film is performed using the resist pattern formed on the upper resist film as a mask, and it is said that a pattern with a high aspect ratio can be formed. That is, according to the multilayer resist method, since the required thickness can be ensured by the lower organic film, the resist film can be made thinner, and formation of a fine pattern with a high aspect ratio becomes possible. The multilayer resist method is basically divided into a method having a two-layer structure of an upper resist film and a lower organic film (two-layer resist method) and a method having a multilayer structure of three or more layers with one or more intermediate layers (such as a metal thin film) provided between the upper resist film and the lower organic film (three-layer resist method).

[0019] Exposure is not particularly limited and can be performed using, for example, radiation such as g-line, h-line, i-line, etc. Further, as the radiation, single light of g-line, h-line or i-line, or mixed light of any two or more of these can be adopted. By adopting mixed light, the exposure time can be shortened. The spectral intensity of each light ray can be appropriately selected according to the type of substrate, etc.

[0020] The development process is not limited to alkali development, and solvent development using a developer containing an organic solvent (organic-based developer) is also included, and it may be selected according to the resist composition. Examples of the alkali developer used for alkali development treatment include an aqueous solution of 0.1 to 10% by mass of tetramethylammonium hydroxide (TMAH). The organic solvent contained in the organic-based developer used for solvent development treatment may be any one that can dissolve the base component in the resist composition and can be appropriately selected from known organic solvents. Specifically, polar solvents such as ketone-based solvents, ester-based solvents, alcohol-based solvents, nitrile-based solvents, amide-based solvents, ether-based solvents, or hydrocarbon-based solvents, etc. can be mentioned.

[0021] <Step (2)> In step (2), one or both of ultraviolet light and visible light are irradiated to cure the pre-pattern. Here, "ultraviolet light" means light with a lower limit of the wavelength range of about 1 nm and an upper limit of the short wavelength end of visible light, and "visible light" means light with a lower limit of the wavelength range of about 360 to 400 nm and an upper limit of about 760 to 830 nm. Step (2) includes a first irradiation step of irradiating the pre-pattern with light in which the region with a wavelength of less than 330 nm among ultraviolet light and visible light is attenuated, and a second irradiation step of irradiating the pre-pattern with light containing both ultraviolet light and visible light after the first irradiation step.

[0022] <Light irradiation device> FIG. 1 is a cross-sectional view of a light irradiation apparatus 1 used in a method for forming a resist pattern according to a first embodiment. For example, the light irradiation apparatus 1 is used in step (2) in the method for forming a resist pattern according to the first embodiment. As shown in FIG. 1, the light irradiation apparatus 1 includes a light irradiation unit 3 that irradiates one or both of ultraviolet rays and visible light onto a substrate 2, and a control unit 4 that controls the light irradiation unit 3. The control unit 4 performs a first irradiation control for irradiating the substrate 2 with light in which a region having a wavelength of less than 330 nm among ultraviolet rays and visible light is attenuated, and after the first irradiation control, a second irradiation control for irradiating the substrate 2 with light including both ultraviolet rays and visible light. Here, the first irradiation control is control for performing a first irradiation step, and the second irradiation control is control for performing a second irradiation step.

[0023] The light irradiation unit 3 includes a light source 10, an optical filter 11 that attenuates light in a region having a wavelength of less than 330 nm, and a detaching mechanism 12 that attaches and detaches the optical filter 11 to and from the light source 10. Examples of the light source for irradiating one or both of ultraviolet rays and visible light include a metal halide lamp, a high-pressure mercury lamp, a low-pressure mercury lamp, an LED lamp, and the like. The optical filter 11 is detachably attached to the lower surface of the light source 10. For example, the detaching mechanism 12 may be a robot mechanism including a robot hand capable of gripping the optical filter 11 and a robot arm capable of moving the robot hand.

[0024] The light irradiation apparatus 1 further includes a chamber 20, a substrate heating unit 30, a substrate support unit 31, a substrate suction unit 32, an irradiation window 40, a window support unit 41, a light source support unit 42, a shutter opening / closing unit 43, a gas supply unit 50, and a heat exhaust unit 51. The control unit 4 comprehensively controls the components of the light irradiation apparatus 1.

[0025] An accommodation space 19 capable of accommodating the substrate 2 is formed inside the chamber 20. The chamber 20 includes an upper structure 21 formed in a box shape that opens downward, and a lower structure 22 connected to the lower part of the upper structure 21.

[0026] The upper structure 21 includes a plate-shaped top plate 21a and a frame-shaped peripheral wall 21b connected to the outer peripheral edge of the top plate 21a. The lower structure 22 is formed in a frame shape that opens in the vertical direction. The outer peripheral edge of the lower structure 22 is connected to the lower end of the peripheral wall 21b of the upper structure 21. A line (gas supply pipe 50a) for supplying an inert gas into the chamber 20 is provided in the lower structure 22.

[0027] The substrate heating unit 30 is provided in the opening of the lower structure 22. The substrate heating unit 30 is connected to the lower surface of the lower structure 22 via an overhanging portion that protrudes outward from the lower end. The substrate heating unit 30 can support the substrate 2 from below. The upper surface of the substrate heating unit 30 is formed in a planar shape along the lower surface of the substrate 2. For example, the substrate heating unit 30 may include a heat source such as a hot plate.

[0028] The substrate support unit 31 is built into the substrate heating unit 30. The substrate support unit 31 has a substrate gripping portion 31a capable of gripping the substrate 2 at the upper part. The upper surface of the substrate gripping portion 31a is exposed from the upper surface of the substrate heating unit 30. The substrate support unit 31 can support the center of the lower surface of the substrate 2 by the substrate gripping portion 31a.

[0029] The substrate adsorption unit 32 is provided in the substrate heating unit 30. The substrate adsorption unit 32 has vacuum suction lines 32a that open in plurality on the upper surface of the substrate heating unit 30. For example, a vacuum pump (not shown) is connected to the vacuum suction lines 32a. The substrate adsorption unit 32 adsorbs the lower surface of the substrate 2 by vacuum suction.

[0030] The irradiation window 40 is disposed between the light source 10 and the substrate 2. The irradiation window 40 is formed in a plate shape that extends horizontally. For example, the irradiation window 40 is formed of synthetic quartz (for example, synthetic quartz glass manufactured using silicon tetrachloride as a raw material), or natural quartz (for example, fused quartz glass manufactured using natural quartz crystal as a raw material), etc. The irradiation window 40 is detachably attached to the upper surface of the window support unit 41. For example, the attachment / detachment mechanism 12 may be a robot mechanism including a robot hand capable of gripping the irradiation window 40 and a robot arm capable of moving the robot hand.

[0031] The window support portion 41 is provided on the upper surface of the lower structure 22. The window support portion 41 can support the outer peripheral portion of the irradiation window 40 from below. The upper surface of the window support portion 41 is disposed above the upper surface of the substrate 2. A line (gas supply pipe 50a) for supplying an inert gas into the chamber 20 is provided in the window support portion 41.

[0032] The light source support portion 42 is provided between the top plate 21a and the window support portion 41. The outer peripheral portion of the light source support portion 42 is connected to the peripheral wall 21b. The light source support portion 42 has a support opening 42a that is larger than the outer shape of the substrate when viewed in the vertical direction. The light source support portion 42 can support the light source 10 above the substrate 2 through the support opening 42a.

[0033] The shutter opening / closing portion 43 is provided between the light source support portion 42 and the window support portion 41. The shutter opening / closing portion 43 is connected to the chamber 20 via a drive mechanism (not shown) or the like. The shutter opening / closing portion 43 is movable between a shielding position (the position shown in FIG. 1) that shields the light source 10 and an exposure position (not shown) that exposes the light source 10.

[0034] Here, the shielding position means a position where the shutter opening / closing portion 43 entirely overlaps the light source 10 when viewed in the vertical direction. The exposure position means a position where the shutter opening / closing portion 43 does not overlap the light source 10 when viewed in the vertical direction. For example, when the shutter opening / closing portion 43 is in the shielding position, the light from the light source 10 is blocked by the shutter opening / closing portion 43, and the substrate 2 is not irradiated with light. On the other hand, when the shutter opening / closing portion 43 is in the exposure position, the light from the light source 10 is not blocked by the shutter opening / closing portion 43, and the substrate 2 is irradiated with light.

[0035] In FIG. 1, an example is shown in which the optical filter 11 is provided on the lower surface of the light source 10 and the shutter opening / closing unit 43 is provided below the optical filter 11. However, the arrangements of the optical filter 11 and the shutter opening / closing unit 43 are not limited to the example of FIG. 1. For example, the arrangements of the optical filter 11 and the shutter opening / closing unit 43 may be reversed from the example of FIG. 1. For example, the shutter opening / closing unit 43 may be arranged below the light source 10, and the optical filter 11 may be arranged below the shutter opening / closing unit 43. That is, as long as the optical filter 11 and the shutter opening / closing unit 43 are arranged below the light source 10, either of them may be arranged on the lower surface side of the light source 10.

[0036] The gas supply unit 50 can supply an inert gas such as nitrogen (N2), helium (He), or argon (Ar) to the accommodation space 19. The gas supply unit 50 includes a gas supply pipe 50a connected to the lower structure 22 and the window support portion 41. In FIG. 1, two gas supply pipes 50a are shown, but the number of installed gas supply pipes 50a is not limited. Further, the gas supply pipe 50a only needs to be connected to be able to supply an inert gas to the accommodation space 19, and the connection portion of the gas supply pipe 50a is not limited.

[0037] The oxygen concentration of the atmosphere in the accommodation space 19 can be adjusted by the gas supply unit 50. The lower the oxygen concentration (mass basis) of the atmosphere in the accommodation space 19, the more preferable. Specifically, it is preferable to set the oxygen concentration of the atmosphere in the accommodation space 19 to 100 ppm or less, and more preferably 20 ppm or less. For example, in the atmosphere when curing the prepattern formed on the substrate 2, by setting the oxygen concentration below the preferable upper limit in this way, the curing of the prepattern can be promoted.

[0038] Although not shown, a pressure adjustment unit (for example, a vacuum pipe connected to the chamber 20) capable of adjusting the pressure in the chamber 20 (that is, the pressure of the atmosphere in the accommodation space 19) may be provided. Thereby, the accommodation space 19 can be adjusted to a desired pressure condition.

[0039] The heat exhaust part 51 is provided on the top plate 21a. The heat exhaust part 51 can discharge the heat in the chamber 20 (i.e., the hot air in the accommodation space 19) to the outside of the chamber 20. The heat exhaust part 51 includes an exhaust pipe 51a connected to the top plate 21a. In FIG. 1, only one exhaust pipe 51a is shown, but the number of installed exhaust pipes 51a is not limited. Further, the exhaust pipe 51a only needs to be connected so as to be able to discharge the hot air (gas) in the accommodation space 19, and the connection part of the exhaust pipe 51a is not limited.

[0040] <First irradiation step> FIG. 2 is an example of the spectrum of light used in the first irradiation step of the first embodiment. As shown in FIG. 2, in the first irradiation step, the prepattern is irradiated with light in which the region with a wavelength of less than 330 nm among ultraviolet light and visible light is attenuated. In the example of FIG. 2, the spectrum of light in which the region with a wavelength of less than 330 nm among ultraviolet light and visible light is generally cut is shown.

[0041] For example, in the first irradiation step, by providing an optical filter 11 (see FIG. 1, for example, a band-pass filter) that attenuates the region with a wavelength of less than 330 nm among ultraviolet light and visible light, the prepattern is irradiated with light in which the region with a wavelength of less than 330 nm among ultraviolet light and visible light is attenuated. For example, in the first irradiation step, it is preferable to irradiate the prepattern with light including a region with a wavelength of 350 nm or more and 450 nm or less among ultraviolet light and visible light (light in which the regions with a wavelength of less than 350 nm and more than 450 nm among ultraviolet light and visible light are attenuated).

[0042] For example, as shown in FIG. 1, before the first irradiation step, the detachable mechanism 12 attaches the optical filter 11 to the lower surface of the light source 10. Thereby, in the first irradiation step, since the light from the light source 10 is irradiated onto the substrate 2 through the optical filter 11, the prepattern on the substrate can be irradiated with light in which the region with a wavelength of less than 330 nm among ultraviolet light and visible light is attenuated (see FIG. 2, preferably light including a region with a wavelength of 350 nm or more and 450 nm or less).

[0043] <Second irradiation step> FIG. 3 is an example of the spectrum of light used in the second irradiation step of the first embodiment. As shown in FIG. 3, in the second irradiation step, after the first irradiation step, the prepattern is irradiated with light including both ultraviolet light and visible light.

[0044] For example, as shown in FIG. 1, the attachment / detachment mechanism 12 removes the optical filter 11 from the lower surface of the light source 10 after the first irradiation step and before the second irradiation step. As a result, in the second irradiation step, since the light from the light source 10 irradiates the substrate 2 without passing through the optical filter 11, the prepattern on the substrate can be irradiated with light including both ultraviolet light and visible light. For example, in the second irradiation step, it is preferable to irradiate the prepattern with light including a region having a wavelength of 200 nm or more and 600 nm or less among ultraviolet light and visible light (see FIG. 3, light in which regions having a wavelength of less than 200 nm and more than 600 nm among ultraviolet light and visible light are attenuated).

[0045] In addition, in the second irradiation step, it is preferable to irradiate the prepattern with light in which a region having a wavelength of less than 230 nm among ultraviolet light and visible light is attenuated. In the example of FIG. 3, the spectrum of light in which a region having a wavelength of less than 230 nm among ultraviolet light and visible light is attenuated is shown by a solid line, and the spectrum of light in which a region having a wavelength of less than 230 nm among ultraviolet light and visible light is not attenuated is shown by a broken line.

[0046] For example, as shown in FIG. 1, the attachment / detachment mechanism 12 removes the irradiation window 40 (for example, a window formed of synthetic quartz, hereinafter also referred to as a "synthetic quartz window") for attenuating a region having a wavelength of less than 330 nm among ultraviolet light and visible light from the window support portion 41 after the first irradiation step and before the second irradiation step, and attaches the irradiation window 40 (for example, a window formed of natural quartz, hereinafter also referred to as a "natural quartz window") for attenuating a region having a wavelength of less than 230 nm among ultraviolet light and visible light to the window support portion 41. That is, the attachment / detachment mechanism 12 replaces the synthetic quartz window with the natural quartz window before the second irradiation step. As a result, in the second irradiation step, since the light from the light source irradiates the substrate 2 through the natural quartz window, the prepattern on the substrate can be irradiated with light in which a region having a wavelength of less than 230 nm among ultraviolet light and visible light is attenuated.

[0047] In step (2), the operation of irradiating the prepattern with light in a specific wavelength range can be performed while heating. In the present invention, the temperature condition when curing the prepattern is preferably 120°C or lower, more preferably 60 - 120°C, still more preferably 70 - 120°C, particularly preferably 80 - 120°C, and most preferably 100 - 120°C. By setting the temperature condition to be equal to or lower than the preferable upper limit value, sublimation is less likely to occur, and equipment contamination is more suppressed. On the other hand, if it is equal to or higher than the preferable lower limit value, the curing of the pattern proceeds more easily. The "temperature condition when curing the prepattern" as referred to in the present invention takes into account the total heat quantity applied to the prepattern and indicates the temperature of the prepattern itself heated by heating means such as a hot plate on which the support is placed or radiation from light irradiation, rather than the set temperature of the heating means. The temperature of the prepattern itself can be measured, for example, by using a thermocouple.

[0048] In the present invention, in step (2), it is preferable to cure the prepattern in an atmosphere with a dew point of -50°C (moisture concentration 38.8 ppm by mass) or higher and -5°C (moisture concentration 4000 ppm by mass) or lower, more preferably in an atmosphere with a dew point of -50°C (moisture concentration 38.8 ppm by mass) or higher and -14°C (moisture concentration 1791 ppm by mass) or lower, and still more preferably in an atmosphere with a dew point of -40°C (moisture concentration 126.7 ppm by mass) or higher and -20°C (moisture concentration 1020 ppm by mass) or lower. If the dew point (moisture concentration) of the atmosphere for curing the prepattern is equal to or lower than the preferable upper limit value, the curing of the pattern proceeds more easily. On the other hand, if it is equal to or higher than the preferable lower limit value, workability and the like are improved (the operation of the apparatus is easier, there are cost merits, etc.).

[0049] In the atmosphere for curing the prepattern, an inert gas such as nitrogen (N2), helium (He), or argon (Ar) can be supplied as a drying gas. By supplying this inert gas, the dew point of the atmosphere can be controlled, and the moisture concentration in the atmosphere can be adjusted. Further, in step (2), the lower the oxygen concentration (mass basis) in the atmosphere for curing the prepattern, the more preferable it is. Specifically, the oxygen concentration is preferably 1000 ppm or less, and more preferably 500 ppm or less. If the oxygen concentration in the atmosphere for curing the prepattern is below the preferable upper limit value, the curing of the pattern tends to proceed more easily.

[0050] <Other steps> The resist pattern forming method of the present invention may have steps other than the above steps (1) and (2). For example, after step (2), a step of performing a heat treatment on the cured resist pattern may be provided. The heating temperature is preferably 100°C or higher, and more preferably 100 to 300°C. By performing this heat treatment, the resist pattern patterned into a predetermined shape is surely cured and excellent in dry etching resistance and the like.

[0051] (Resist composition) The resist composition that can be used in the resist pattern forming method of the present invention may be a positive resist composition in which the exposed portion is dissolved and removed by exposure and development in step (1) to form a prepattern, or a negative resist composition in which the unexposed portion is dissolved and removed to form a prepattern. Examples of such a resist composition include the resist compositions (r1) to (r4) exemplified below.

[0052] In the present specification and claims, "aliphatic" is a relative concept with respect to aromatic, and is defined to mean a group, compound, etc. that does not have aromaticity. "Alkyl group" shall include linear, branched, and cyclic monovalent saturated hydrocarbon groups unless otherwise specified. The same applies to the alkyl group in the alkoxy group. "Alkylene group" shall include linear, branched, and cyclic divalent saturated hydrocarbon groups unless otherwise specified. "Halogenated alkyl group" is a group in which some or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. "Fluorinated alkyl group" or "fluorinated alkylene group" refers to a group in which some or all of the hydrogen atoms of the alkyl group or alkylene group are substituted with fluorine atoms. "Constituent unit" means a monomer unit (monomeric unit) that constitutes a polymer compound (resin, polymer, copolymer). When it is described as "may have a substituent", it includes both the case of substituting a hydrogen atom (-H) with a monovalent group and the case of substituting a methylene group (-CH2-) with a divalent group. "Exposure" is a concept that includes all irradiations of radiation.

[0053] <Resist composition (r1)> The resist composition (r1) is a positive resist composition obtained by dissolving an alkali-soluble resin, a specific phenolic compound as a sensitivity improver, and a quinonediazide esterified product as a photosensitive component in an organic solvent.

[0054] In the resist composition (r1), the alkali-soluble resin can be arbitrarily selected from those that can be usually used as a film-forming substance. For example, phenolic resins, acrylic resins, copolymers of styrene and acrylic acid, polymers of hydroxystyrene, polyvinylphenol, polyα-methylvinylphenol, etc. that are known as film-forming resins for positive resist compositions can be mentioned. Among these, a phenolic resin is particularly preferably used, and among them, a novolak resin that easily dissolves in an aqueous alkali solution without swelling and has excellent developability is suitable.

[0055] Examples of phenolic resins include condensation reaction products of phenols and aldehydes, condensation reaction products of phenols and ketones, vinylphenol polymers, isopropenylphenol polymers, hydrogenation reaction products of these phenolic resins, and the like.

[0056] Examples of phenols in the condensation reaction product include xylenols such as phenol, m-cresol, p-cresol, o-cresol, 2,3-xylenol, 2,5-xylenol, 3,5-xylenol, 3,4-xylenol; alkylphenols such as m-ethylphenol, p-ethylphenol, o-ethylphenol, 2,3,5-trimethylphenol, 2,3,5-triethylphenol, 4-tert-butylphenol, 3-tert-butylphenol, 2-tert-butylphenol, 2-tert-butyl-4-methylphenol, 2-tert-butyl-5-methylphenol; alkoxyphenols such as p-methoxyphenol, m-methoxyphenol, p-ethoxyphenol, m-ethoxyphenol, p-propoxyphenol, m-propoxyphenol; isopropenylphenols such as o-isopropenylphenol, p-isopropenylphenol, 2-methyl-4-isopropenylphenol, 2-ethyl-4-isopropenylphenol; arylphenols such as phenylphenol; and polyhydroxyphenols such as 4,4'-dihydroxybiphenyl, bisphenol A, resorcinol, hydroquinone, pyrogallol. These may be used alone or in combination of two or more. Among these phenols, m-cresol, p-cresol, 2,5-xylenol, 3,5-xylenol, and 2,3,5-trimethylphenol are particularly preferred.

[0057] Examples of aldehydes in the condensation reaction product include formaldehyde, paraformaldehyde, trioxane, acetaldehyde, propionaldehyde, butyraldehyde, trimethylacetaldehyde, acrolein, crotonaldehyde, cyclohexanealdehyde, furfural, furylacrolein, benzaldehyde, terephthalaldehyde, phenylacetaldehyde, α-phenylpropylaldehyde, β-phenylpropylaldehyde, o-hydroxybenzaldehyde, m-hydroxybenzaldehyde, p-hydroxybenzaldehyde, o-methylbenzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde, o-chlorobenzaldehyde, m-chlorobenzaldehyde, p-chlorobenzaldehyde, cinnamaldehyde, etc. These may be used alone or in combination of two or more. Among these aldehydes, formaldehyde is preferred due to its easy availability, and in particular, it is preferable to use a combination of hydroxybenzaldehydes and formaldehyde to improve heat resistance.

[0058] Examples of ketones in the condensation reaction product include acetone, methyl ethyl ketone, diethyl ketone, diphenyl ketone, etc. These may be used alone or in combination of two or more. In the combination of phenols and ketones, the combination of pyrogallol and acetone is particularly preferred.

[0059] The condensation reaction product of phenols and aldehydes or ketones can be produced by a known method in the presence of an acidic catalyst. As the acidic catalyst, hydrochloric acid, sulfuric acid, formic acid, oxalic acid, p-toluenesulfonic acid, etc. can be used. The condensation reaction product thus obtained is preferably one in which the low molecular weight region is cut by treatment such as fractionation, because it has excellent heat resistance. The treatment such as fractionation is carried out by dissolving the resin obtained by the condensation reaction in a good solvent, for example, alcohols such as methanol and ethanol; ketones such as acetone and methyl ethyl ketone; ethylene glycol monoethyl ether acetate, tetrahydrofuran, etc., and then pouring it into water and precipitating it.

[0060] Among the above, a novolak resin containing 60 mol% or more of p-cresol repeating units and 30 mol% or more of m-cresol repeating units in all phenol-based repeating units and having a polystyrene-reduced weight average molecular weight (Mw) of 2000 to 8000 is particularly preferred. By setting the p-cresol repeating unit to 60 mol% or more, it is possible to make it difficult to cause a change in sensitivity to temperature unevenness during heat treatment. Also, by setting the m-cresol repeating unit to 30 mol% or more, good sensitivity can be obtained.

[0061] The alkali-soluble resin may contain other phenol-based repeating units such as xylenol-based repeating units and trimethylphenol-based repeating units. Particularly preferred is a two-component novolak resin composed of 60 to 70 mol% of p-cresol repeating units and 40 to 30 mol% of m-cresol repeating units, and having a content of dinuclear bodies (condensed molecules having two phenol nuclei) of phenols of 10% or less in the GPC (gel permeation chromatography) method. A novolak resin with a low content of low molecular weight bodies of phenols is preferred. Since dinuclear bodies sublime during pre-baking or post-baking at high temperatures (for example, 130 °C) and stain the top plate of the furnace, etc., and further stain the glass substrate coated with the resist composition, resulting in a decrease in its yield, a novolak resin with a low content thereof is preferred.

[0062] In the resist composition (r1), examples of the sensitivity improver include phenol compounds represented by the following general formula (I).

[0063] [Chemical formula]

[0064] [In the formula, R1 to R8 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 6 carbon atoms; R9 to R11 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; Q represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a group that combines with R9 to form a cycloalkyl group having a carbon atom chain of 3 to 6, or a group represented by the following chemical formula (II)

[0065] [Chemical formula]

[0066] (In the formula, R12 and R13 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 6 carbon atoms; c represents an integer of 1 to 3; a and b represent integers of 1 to 3; d represents an integer of 0 to 3; n represents an integer of 0 to 3.)

[0067] As sensitivity improvers in the resist composition (r1), tris(4-hydroxyphenyl)methane, bis(4-hydroxy-3-methylphenyl)-2-hydroxyphenylmethane, bis(4-hydroxy-2,3,5-trimethylphenyl)-2-hydroxyphenylmethane, bis(4-hydroxy-3,5-dimethylphenyl)-4-hydroxyphenylmethane, bis(4-hydroxy-3,5-dimethylphenyl)-3-hydroxyphenylmethane, bis(4-hydroxy-3,5-dimethylphenyl)-2-hydroxyphenylmethane, bis(4-hydroxy-2,5-dimethylphenyl)-4-hydroxyphenylmethane, bis(4-hydroxy-2,5-dimethylphenyl)-3-hydroxyphenylmethane, bis(4-hydroxy-2,5-dimethylphenyl)-2-hydroxyphenylmethane, bis(4-hydroxy-3,5-dimethylphenyl)-3,4-dihydroxyphenylmethane, bis(4-hydroxy-2,5-dimethylphenyl)-3,4-dihydroxyphenylmethane, bis(4-hydroxy-2,5-dimethylphenyl)-2,4-dihydroxyphenylmethane, bis(4-hydroxyphenyl)-3-methoxy-4-hydroxyphenylmethane, bis(5-cyclohexyl-4-hydroxy-2-methylphenyl)-4-hydroxyphenylmethane, bis(5-cyclohexyl-4-hydroxy-2-methylphenyl)-3-hydroxyphenylmethane, bis(5-cyclohexyl-4-hydroxy-2-methylphenyl)-2-hydroxyphenylmethane, bis(5-cyclohexyl-4-hydroxy-2-methylphenyl)-3,4-dihydroxyphenylmethane, 1-[1-(4-hydroxyphenyl)isopropyl]-4-[1,1-bis(4-hydroxyphenyl)ethyl]benzene, 1-[1-(3-methyl-4-hydroxyphenyl)isopropyl]-4-[1,1-bis(3-methyl-4-hydroxyphenyl)ethyl]benzene, 2-(2,3,4-trihydroxyphenyl)-2-(2’,3’,4’-trihydroxyphenyl)propane, 2-(2,4-dihydroxyphenyl)-2-(2’,4’-Dihydroxyphenyl)propane, 2-(4-hydroxyphenyl)-2-(4’-hydroxyphenyl)propane, 2-(3-fluoro-4-hydroxyphenyl)-2-(3’-fluoro-4’-hydroxyphenyl)propane, 2-(2,4-dihydroxyphenyl)-2-(4’-hydroxyphenyl)propane, 2-(2,3,4-trihydroxyphenyl)-2-(4’-hydroxyphenyl)propane, 2-(2,3,4-trihydroxyphenyl)-2-(4’-hydroxy-3’,5’-dimethylphenyl)propane, bis(2,3,4-trihydroxyphenyl)methane, bis(2,4-dihydroxyphenyl)methane, 2,3,4-trihydroxyphenyl-4’-hydroxyphenylmethane, 1,1-di(4-hydroxyphenyl)cyclohexane, 2,4-bis[1-(4-hydroxyphenyl)isopropyl]-5-hydroxyphenol and the like can be mentioned.,

[0068] Among these, bis(4-hydroxy-3-methylphenyl)-2-hydroxyphenylmethane, bis(4-hydroxy-2,3,5-trimethylphenyl)-2-hydroxyphenylmethane, 2,4-bis[1-(4-hydroxyphenyl)isopropyl]-5-hydroxyphenol, 1,1-di(4-hydroxyphenyl)cyclohexane, 1-[1-(4-hydroxyphenyl)isopropyl]-4-[1,1-bis(4-hydroxyphenyl)ethyl]benzene and the like are preferable because they are particularly excellent in the sensitivity improving effect. The sensitivity improver may be used alone or in combination of two or more. The content of the sensitivity improver is preferably 5 to 25 parts by mass, more preferably 10 to 20 parts by mass, based on 100 parts by mass of the alkali-soluble resin.,

[0069] In the resist composition (r1), examples of the photosensitive component include a quinonediazide esterified product (photosensitive component 1) represented by the following general formula (III), a quinonediazide esterified product (photosensitive component 2) represented by the following general formula (IV), an esterified product of the phenol compound represented by the above general formula (I) and a 1,2-naphthoquinonediazide-5(or 4)-sulfonyl compound, and the like.,

[0070]

Chem.

[0071] [In formula (III), R14 independently represents an alkyl group having 1 to 5 carbon atoms, D independently represents a hydrogen atom or a 1,2-naphthoquinonediazide-5-sulfonyl group, and at least one of D represents a 1,2-naphthoquinonediazide-5-sulfonyl group. l and m each independently represent 1 or 2. In formula (IV), a plurality of Ds each independently represent a hydrogen atom or a 1,2-naphthoquinonediazide-5-sulfonyl group, and at least one of D is a 1,2-naphthoquinonediazide-5-sulfonyl group.]

[0072] The average esterification rate of the photosensitive component 1 is preferably 40 to 60%, more preferably 45 to 55%. If this average esterification rate is less than 40%, film loss after development is likely to occur and the residual film rate tends to be low. On the other hand, if it exceeds 60%, the sensitivity tends to be significantly inferior. As the photosensitive component 1, a quinonediazide ester compound obtained from a 1,2-naphthoquinonediazito-5-sulfonyl compound of bis(2-methyl-4-hydroxy-5-cyclohexylphenyl)-3,4-dihydroxyphenylmethane is preferable in that a resist composition that is relatively inexpensive and excellent in sensitivity, resolution, and linearity can be prepared. Among them, the one with an esterification rate of 50% is most preferable.

[0073] The average esterification rate of the photosensitive component 2 is preferably 50 to 70%, more preferably 55 to 65%. By setting this average esterification rate within the above range, it is possible to well balance the suppression of film loss after development and the improvement of storage stability. As the photosensitive component 2, a quinonediazide ester compound obtained from a 1,2-naphthoquinonediazito-5-sulfonyl compound of 2,3,4,4'-tetrahydroxybenzophenone is preferable in that a resist composition that is very inexpensive and excellent in sensitivity can be adjusted. Among them, the one with an esterification rate of 59% is most preferable.

[0074] The photosensitive component may be used alone or in combination of two or more. The content of the photosensitive component is preferably 15 to 40 parts by mass, more preferably 20 to 30 parts by mass, based on 100 parts by mass of the total amount of the alkali-soluble resin and the sensitivity improver.

[0075] In the resist composition (r1), examples of the organic solvent include ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, and 2-heptanone; polyhydric alcohols such as ethylene glycol, propylene glycol, diethylene glycol, ethylene glycol monoacetate, propylene glycol monoacetate, diethylene glycol monoacetate, or their monomethyl ethers, monoethyl ethers, monopropyl ethers, monobutyl ethers, or monophenyl ethers, and their derivatives; cyclic ethers such as dioxane; esters such as ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; benzene, toluene, xylene, methyl isobutyl ketone, methanol, ethanol, propanol, butanol, hexanol, cyclohexanol, methyl carbonate, ethyl carbonate, propyl carbonate, butyl carbonate, and the like. The organic solvent may be used alone or in combination of two or more. Among these, propylene glycol monomethyl ether acetate (PGMEA) is preferable in that it gives excellent coatability to the resist composition and excellent film thickness uniformity to the resist film on the substrate. It is preferable to use PGMEA as a single solvent, but an organic solvent other than PGMEA can also be used in mixture therewith. Examples of such an organic solvent include ethyl lactate, γ-butyrolactone, and propylene glycol monobutyl ether.

[0076] In the resist composition (r1), the total amount of the alkali-soluble resin, the sensitivity improver, and the photosensitive component is preferably 30% by mass or less, more preferably 20 - 28% by mass, based on the total mass of the composition, from the viewpoint of excellent coatability on the support. In this case, considering the amount of the additives optionally used hereinafter, the content of the organic solvent is preferably 50 - 90% by mass, more preferably 65 - 85% by mass, and still more preferably 70 - 75% by mass, based on the total mass of the composition.

[0077] In the resist composition (r1), if necessary, ultraviolet absorbers for preventing halation, such as 2,2’,4,4’-tetrahydroxybenzophenone, 4-dimethylamino-2’,4’-dihydroxybenzophenone, 5-amino-3-methyl-1-phenyl-4-(4-hydroxyphenylazo)pyrazole, 4-dimethylamino-4’-hydroxyazobenzene, 4-diethylamino-4’-ethoxyazobenzene, 4-diethylaminoazobenzene, curcumin, etc. can be used. Also, in the resist composition (r1), surfactants for preventing striation, such as Fluorad FC-430, FC431 (trade names, manufactured by Sumitomo 3M Limited); F-Top EF122A, EF122B, EF122C, EF126 (trade names, manufactured by Tochem Products Co., Ltd.); XR-104 (product name, manufactured by Dainippon Ink and Chemicals, Inc.), BYK-310 (product name, manufactured by BYK-Chemie Japan Co., Ltd.), etc. can be used. Further, in the resist composition (r1), preservatives such as benzoquinone, naphthoquinone, p-toluenesulfonic acid; and furthermore, conventional additives such as additional resins, plasticizers, stabilizers, contrast improvers, etc. can be added and contained as necessary.

[0078] <The resist composition (r2)> The resist composition (r2) is a positive resist composition containing a copolymer having a repeating unit represented by the following general formula (1) and a repeating unit represented by general formula (2), and a photosensitive component. When the resist film formed by the resist composition (r2) is applied to, for example, a microlens, a microlens with good heat resistance and chemical resistance can be formed.

[0079] [Chemical formula]

[0080] [In formulas (1) and (2), R0 each independently represents a hydrogen atom or a methyl group. R21 represents a single bond or an alkylene group having 1 to 5 carbon atoms. R22 represents an alkyl group having 1 to 5 carbon atoms. R23 represents a monovalent organic group having thermocrosslinkability. p represents an integer of 1 to 5, q represents an integer of 0 to 4, and p + q is 5 or less. However, a plurality of R0s and R22s in the repeating unit may be different from each other.]

[0081] ·The repeating unit represented by general formula (1) The repeating unit represented by the general formula (1) (hereinafter also referred to as "repeating unit (1)") exhibits alkali solubility. In formula (1), R0 is preferably a methyl group. Examples of the alkylene group having 1 to 5 carbon atoms in R21 include a methylene group, an ethylene group, a propylene group, an isopropylene group, an n-butylene group, an isobutylene group, a tert-butylene group, a pentylene group, an isopentylene group, and a neopentyl group. Among them, a methylene group and an ethylene group are preferable. At least one hydroxyl group is bonded to the benzene ring of the repeating unit (1). p indicating the number of bonded hydroxyl groups is an integer of 1 to 5, and 1 is preferable from the viewpoint of production. In the benzene ring, the bonding position of at least one of the hydroxyl groups is preferably the 4-position when the bonding position of "-C(=O)-O-R21-" is the 1-position. Further, a linear or branched alkyl group having 1 to 5 carbon atoms may be bonded to the benzene ring of the repeating unit (1) as R22. Examples of such an alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. Industrially, a methyl group or an ethyl group is more preferable. q represents an integer of 0 to 4, and 0 is more preferable.

[0082] The repeating unit (1) can be used alone or in a mixture of two or more. In the copolymer having the repeating unit (1) and the repeating unit (2), the content of the repeating unit (1) is preferably 20 to 50 mol% based on the total of the repeating units constituting the copolymer. By setting it within this range, it becomes easy to ensure alkali solubility during development.

[0083] · The repeating unit represented by the general formula (2) The repeating unit represented by the general formula (2) (hereinafter also referred to as "repeating unit (2)") contains a thermally crosslinkable group (R23). In formula (2), R0 is preferably a methyl group. Examples of the alkylene group having 1 to 5 carbon atoms in R21 include a methylene group, an ethylene group, a propylene group, an isopropylene group, an n-butylene group, an isobutylene group, a tert-butylene group, a pentylene group, an isopentylene group, and a neopentylene group. Among them, a methylene group and an ethylene group are preferred. In formula (2), R23 represents a monovalent organic group having thermally crosslinkable properties (hereinafter this organic group is referred to as a "thermally crosslinkable group"). The thermally crosslinkable group is a group that crosslinks when heat is applied. As R23, it is preferably an organic group containing either an epoxy group or an oxetanyl group. Among these, R23 is more preferably an organic group containing an epoxy group in terms of being able to improve the crosslinking efficiency by heat treatment.

[0084] The repeating unit (2) can be used alone or in a mixture of two or more. In the copolymer having the repeating unit (1) and the repeating unit (2), the content of the repeating unit (2) is preferably 50 to 80 mol% based on the total of the repeating units constituting the copolymer. In the copolymer, by setting the content of the repeating unit (2) to be not less than the preferable lower limit value, it is possible to reduce the decrease in transmittance due to heat treatment and it becomes easier to ensure thermosetting properties. On the other hand, by setting it to be not more than the preferable upper limit value, the generation of residues during development can be further suppressed.

[0085] The copolymer having repeating unit (1) and repeating unit (2) may be composed of either random polymerization or block polymerization. As described above, by using a copolymer having different repeating units of repeating unit (1) and repeating unit (2), it becomes easy to control the alkali dissolution rate and the heat resistance. The mass average molecular weight (Mw: measured value by gel permeation chromatography (GPC) in terms of styrene) of the copolymer is preferably from 10,000 to 30,000. When the Mw of the copolymer is equal to or higher than the preferable lower limit value, the heat resistance is improved. For example, when forming a microlens using the copolymer, the lens shape can be easily maintained even during the firing process for curing the microlens. On the other hand, by setting it below the preferable upper limit value, the generation of residues during development can be suppressed. In addition, the resist composition (r2) preferably contains a copolymer having repeating unit (1) and repeating unit (2) and having an Mw of 10,000 to 30,000, so that a resist film having a high glass transition temperature and heat resistance capable of maintaining its shape even when exposed to a high temperature can be formed. Further, since the resist composition (r2) contains a copolymer having a repeating unit containing a thermal crosslinking group (R23), a resist film having high hardness and excellent chemical resistance can be formed.

[0086] The resist composition (r2) may be used in combination with a resin component other than the copolymer having the above-mentioned repeating unit (1) and repeating unit (2). Examples of such resin components include acrylic resins, hydroxystyrene resins, novolak resins, and the like.

[0087] The photosensitive component used in the resist composition (r2) may be the same as the photosensitive component used in the above-described resist composition (r1). This photosensitive component may be used alone or in combination of two or more. In the resist composition (r2), the content of the photosensitive component is preferably in the range of 10 to 40% by mass based on the solid content of the resist composition (r2). By setting the content of the photosensitive component to be equal to or higher than the preferable lower limit value, a pattern can be formed well. When the resist composition (r2) is used for microlens formation, a lens shape can be formed well during development. On the other hand, by setting the content of the photosensitive component to be equal to or lower than the preferable upper limit value, the developability can be improved and the generation of residues during development can be suppressed.

[0088] In the resist composition (r2), a copolymer having the repeating unit (1) and the repeating unit (2), and components other than the photosensitive component can be used as necessary. In the resist composition (r2), for example, from the viewpoint of coatability on a support, a surfactant may be blended, or various additives such as a sensitizer and an antifoaming agent may be added. The resist composition (r2) can be prepared by dissolving the copolymer, the photosensitive component, and, if necessary, components other than these in an organic solvent.

[0089] <Resist composition (r3)> The resist composition (r3) is a chemically amplified negative resist composition containing an alkali-soluble resin and an acid generator. In the resist composition (r3), the alkali-soluble resin can be arbitrarily selected from conventionally known resins used as the base resin of a generally negative chemically amplified resist composition according to the light source used for exposure. For example, novolak resins, polyhydroxystyrene resins, acrylic resins, etc. can be mentioned. The alkali-soluble resin may be used alone, such as novolak resin, polyhydroxystyrene resin, acrylic resin, etc., or two or more of them may be mixed and used. When the resist composition (r3) contains an alkali-soluble resin, an acid generator, and a plasticizer described later, the content of the alkali-soluble resin is preferably 30 to 99 parts by mass, more preferably 65 to 95 parts by mass, based on 100 parts by mass of the total solid content of the alkali-soluble resin, the acid generator, and the plasticizer.

[0090] In the resist composition (r3), the acid generator is not particularly limited as long as it is a compound that generates an acid directly or indirectly by irradiation with light, and can be arbitrarily selected from conventionally known ones and used. The acid generator may be used alone or in combination of two or more. In the resist composition (r3), the content of the acid generator is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 2 parts by mass, and even more preferably 0.1 to 1 part by mass, based on 100 parts by mass of the total solid content of the resist composition (r3).

[0091] In the resist composition (r3), components other than the alkali-soluble resin and the acid generator can be used as necessary. For example, in addition to the alkali-soluble resin and the acid generator, a plasticizer may be blended. By blending a plasticizer, the occurrence of cracks can be suppressed. Examples of the plasticizer include acrylic resins and polyvinyl resins.

[0092] In addition to an alkali-soluble resin and an acid generator, or in addition to an alkali-soluble resin, an acid generator, and a plasticizer, a crosslinking agent may be blended in the resist composition (r3). Examples of such crosslinking agents include amino compounds such as melamine resins, urea resins, guanamine resins, glycoluril-formaldehyde resins, succinylamide-formaldehyde resins, ethyleneurea-formaldehyde resins, etc., and in particular, alkoxymethylated amino resins such as alkoxymethylated melamine resins and alkoxymethylated urea resins can be preferably used.

[0093] In the resist composition (r3), in addition to the above components, a fluorine-containing polymer compound having a structural unit containing a base-dissociable group (preferably a base-dissociable group containing a fluorine atom) may be blended as necessary. The "base-dissociable group" is an organic group that can be dissociated by the action of a base. That is, the "base-dissociable group" is dissociated by the action of an alkaline developer (for example, a 2.38 mass% aqueous TMAH solution at 23°C). When the base-dissociable group is dissociated by the action of an alkaline developer, a hydrophilic group appears, so the affinity for the alkaline developer is improved. That is, the fluorine-containing polymer compound is a "polymer compound having a fluorine atom" with high hydrophobicity, but at the same time, it also has a "base-dissociable group", so the affinity for the alkaline developer is improved by the action of the alkaline developer. Therefore, by using the negative resist composition, a resist film that is hydrophobic during immersion exposure and dissolves well in the alkaline developer during development can be formed.

[0094] In the resist composition (r3), in addition to the above components, a quencher such as a secondary or tertiary amine such as triethylamine, tributylamine, dibutylamine, triethanolamine, etc.; a surfactant, a functional silane coupling agent as an adhesion aid, a filler, a colorant, a viscosity modifier, an antifoaming agent, etc. can also be added as necessary. The resist composition (r3) can be prepared by dissolving an alkali-soluble resin, an acid generator, and, as necessary, components other than these in an organic solvent.

[0095] <Resist composition (r4)> The resist composition (r4) is a negative resist composition containing an alkali-soluble resin, a cationic polymerization initiator, and a sensitizer. In the resist composition (r4), examples of the alkali-soluble resin include polyfunctional epoxy resins. The polyfunctional epoxy resin is not particularly limited as long as it has an epoxy group sufficient for forming a thick resist pattern in one molecule, and examples thereof include polyfunctional phenol novolak type epoxy resins, polyfunctional orthocresol novolak type epoxy resins, polyfunctional triphenyl type novolak type epoxy resins, polyfunctional bisphenol A novolak type epoxy resins, and the like. Further, as the alkali-soluble resin, an alkali-soluble base material having photocurability can also be used.

[0096] In the resist composition (r4), the cationic polymerization initiator generates a cationic part upon irradiation with ultraviolet rays, far ultraviolet rays, excimer lasers such as KrF and ArF, X-rays, or electron beams, and the cationic part can be a polymerization initiator. As this cationic polymerization initiator, it is possible to arbitrarily select and use from among conventionally known ones. The cationic polymerization initiator may be used alone or in combination of two or more. In the resist composition (r4), the content of the cationic polymerization initiator is preferably 0.5 to 20 parts by mass with respect to 100 parts by mass of the alkali-soluble resin. By setting the content of the cationic polymerization initiator to 0.5 part by mass or more, sufficient photosensitivity can be obtained. On the other hand, by setting it to 20 parts by mass or less, the characteristics of the resist film are improved.

[0097] In the resist composition (r4), the sensitizer is preferably a naphthalene derivative, anthracene or its derivative capable of forming a crosslink with the above polyfunctional epoxy resin. Due to the sensitizing function of such a sensitizer, the sensitivity of the resist composition can be further increased. Among them, in particular, it is preferable to contain a sensitizer composed of dihydroxynaphthalene having two hydroxyl groups or anthracene. Since these sensitizers have a plurality of aromatic rings, the hardness of the resist pattern can be increased. The sensitizer may be used alone or in combination of two or more. In the resist composition (r4), the content of the sensitizer is preferably 1 to 50 parts by mass with respect to 100 parts by mass of the alkali-soluble resin.

[0098] In the resist composition (r4), components other than the alkali-soluble resin, the cationic polymerization initiator, and the sensitizer can be used as necessary. For example, from the viewpoint of further enhancing the curability of the resist pattern, it is preferable to use an oxetane derivative. In addition, a photopolymerization initiator for a photosensitive resin composition other than the above-described cationic polymerization initiator can also be used. In addition, since curing failure during exposure hardly occurs and sufficient heat resistance is easily obtained, a photopolymerizable compound may be blended.

[0099] Furthermore, in the resist composition (r4), if desired, miscible additives, for example, conventionally known ones such as additional resins, plasticizers, stabilizers, colorants, coupling agents, leveling agents, etc. for improving the performance of the resist pattern can be appropriately blended. The resist composition (r4) can be prepared by dissolving an alkali-soluble resin, a cationic polymerization initiator, a sensitizer, and, if necessary, components other than these in an organic solvent.

[0100] <Explanation of each step of the method for forming a resist pattern> FIG. 4 is an explanatory diagram of step (1) of forming a prepattern in the first embodiment. FIG. 5 is an explanatory diagram of the first irradiation step in step (2) of curing the prepattern in the first embodiment following FIG. 4. FIG. 6 is an explanatory diagram of the second irradiation step in the above step (2) following FIG. 5. FIG. 7 is an explanatory diagram of the resist pattern formed on the substrate following FIG. 6.

[0101] As shown in FIG. 4, in step (1), after exposing the resist film formed on the substrate using a resist composition, it is patterned by development to form a prepattern. In FIG. 4, a trapezoidal prepattern is shown. After step (1), the process proceeds to step (2).

[0102] As shown in FIG. 5, in step (2), first, in the first irradiation step, the prepattern is irradiated with light having an attenuated region of less than 330 nm among ultraviolet and visible light (see arrow L1 in FIG. 5). For example, in the first irradiation step, by providing an optical filter that attenuates the region of less than 330 nm with respect to the light source, the prepattern is irradiated with light having an attenuated region of less than 330 nm among ultraviolet and visible light. After the first irradiation step, the process proceeds to the second irradiation step.

[0103] As shown in FIG. 6, in the second irradiation step, the prepattern is irradiated with light including both ultraviolet and visible light (see arrow L2 in FIG. 6). For example, in the second irradiation step, by removing the optical filter from the light source, the prepattern is irradiated with light including both ultraviolet and visible light. For example, in the second irradiation step, by providing a natural quartz window, the prepattern is irradiated with light having an attenuated region of less than 230 nm among ultraviolet and visible light.

[0104] As shown in FIG. 7, by going through the second irradiation step, the prepattern is cured. Thereby, a resist pattern can be formed on the substrate. Incidentally, if necessary, after the second irradiation step, a heat treatment may be performed on the resist pattern.

[0105] <Advantages and effects> As described above, the resist pattern forming method of the present embodiment includes a step (1) of exposing a resist film formed on a substrate using a resist composition and then patterning by development to form a prepattern, and a step (2) of irradiating the prepattern with one or both of ultraviolet light and visible light to cure the prepattern. The step (2) includes a first irradiation step of irradiating the prepattern with light having an attenuated region of less than 330 nm in wavelength among ultraviolet light and visible light, and a second irradiation step of irradiating the prepattern with light including both ultraviolet light and visible light after the first irradiation step. For example, if the prepattern is irradiated with ultraviolet light having a wavelength of 254 nm, a cured layer may be partially formed in the surface layer portion of the prepattern. In this case, even if the prepattern is irradiated with ultraviolet light, it is blocked by the cured layer, and curing hardly progresses inside the prepattern. As a result, a resist pattern with insufficient internal curing may be formed. If the inside of the resist pattern is not sufficiently cured, wrinkles and roughness are likely to occur in the resist pattern during heat treatment. Also, simply continuing ultraviolet irradiation to promote curing inside the prepattern is likely to take a long time to form the resist pattern. The reason why a cured layer is partially formed in the surface layer portion of the prepattern when the prepattern is irradiated with ultraviolet light having a wavelength of 254 nm is considered to be that when the prepattern is irradiated with ultraviolet light having strong energy of 254 nm (see arrow Lx shown in FIG. 8), ethylene groups (-C=C-) that are difficult to transmit long wavelengths are generated in the organic film, making it difficult for ultraviolet light having a wavelength of 365 nm to pass through. Therefore, it is considered that the surface layer portion of the prepattern is polymerized, but polymerization hardly progresses inside the prepattern. When heat treatment is performed after ultraviolet irradiation, the reason for the occurrence of wrinkles and roughness is considered to be due to insufficient polymerization inside the resist pattern. On the other hand, according to the present embodiment, in the first irradiation step, by irradiating the prepattern with light having an attenuated region of less than 330 nm in wavelength among ultraviolet light and visible light, it is possible to suppress the formation of a cured layer partially in the surface layer portion of the prepattern (see FIG. 5).Therefore, in the second irradiation step after the first irradiation step, the prepattern can be irradiated with light including both ultraviolet light and visible light in a state where the formation of the cured layer is suppressed in the surface layer portion of the prepattern (see FIG. 6). As a result, in the second irradiation step, since the light is suppressed from being blocked by the cured layer (since the light easily enters the inside of the prepattern), the curing inside the prepattern can sufficiently progress in a short time. Therefore, a resist pattern in which the surface layer portion and the inside are sufficiently cured can be formed (see FIG. 7). As a result, it is possible to suppress the occurrence of wrinkles and roughness in the resist pattern during the heat treatment. Therefore, a resist pattern having excellent heat resistance can be formed in a short time. By the way, there is a case where a high melting point metal (for example, tungsten or the like) is wired on the substrate by vapor deposition. In this case, high heat is applied to the substrate, and as a result, the resist pattern reaches a high temperature (for example, a temperature of 160° C. or higher). According to the present embodiment, since a resist pattern having excellent heat resistance can be formed, it can withstand high temperatures even when a high melting point metal is vapor-deposited on the substrate.

[0106] In this embodiment, in the second irradiation step, by irradiating the prepattern with light in which the region with a wavelength of less than 230 nm among ultraviolet rays and visible light is attenuated, the following effects can be achieved. For example, if the prepattern is irradiated with light having a wavelength of less than 230 nm among ultraviolet rays and visible light in the second irradiation step, ozone (O3) may be generated. In this case, the cured layer formed on the surface layer portion of the prepattern may be destroyed by the ozone. As described above, when the prepattern is irradiated with ultraviolet rays having a wavelength of 254 nm, a cured layer is partially formed on the surface layer portion of the prepattern. At the same time, however, ultraviolet rays with strong energy of less than 230 nm are likely to generate ozone (O3) and start decomposing the formed cured layer (see Fig. 9). At the same time, since an ethylene group (-C=C-) is generated, it becomes difficult for ultraviolet rays with a wavelength of 365 nm to pass through. As a result, the surface layer portion of the prepattern is polymerized but not very strongly, and it is considered that the polymerization inside the prepattern is difficult to proceed. On the other hand, according to this embodiment, in the second irradiation step, by irradiating the prepattern with light in which the region with a wavelength of less than 230 nm among ultraviolet rays and visible light is attenuated, the generation of ozone can be suppressed. Therefore, it is possible to suppress the destruction of the cured layer formed on the surface layer portion of the prepattern.

[0107] In this embodiment, in the first irradiation step, by providing an optical filter 11 that attenuates light in the region with a wavelength of less than 330 nm with respect to the light source 10, the prepattern is irradiated with light in which the region with a wavelength of less than 330 nm among ultraviolet rays and visible light is attenuated. In the second irradiation step, by removing the optical filter 11 from the light source 10, the prepattern is irradiated with light including both ultraviolet rays and visible light, thereby achieving the following effects. The common light source 10 can be used in both the first irradiation step and the second irradiation step.

[0108] In the light irradiation device 1 of the present embodiment, the light irradiation unit 3 includes a light source 10, an optical filter 11 that attenuates light in a region with a wavelength of less than 330 nm, and a detaching mechanism 12 that attaches and detaches the optical filter 11 to and from the light source 10. In the first irradiation control, the substrate 2 is irradiated with light in which the region with a wavelength of less than 330 nm among ultraviolet rays and visible light is attenuated by providing the optical filter 11 to the light source 10. In the second irradiation control, the substrate 2 is irradiated with light including both ultraviolet rays and visible light by removing the optical filter 11 from the light source 10.

[0109] <Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIG. 10. In the second embodiment, the configuration of the light irradiation unit is particularly different from that of the first embodiment. In FIG. 10, the same reference numerals are given to the same configurations as those in the first embodiment, and detailed descriptions thereof are omitted. FIG. 10 is a cross-sectional view of a light irradiation device 201 used in the resist pattern forming method of the second embodiment.

[0110] As shown in FIG. 10, the light irradiation unit 203 includes a first light source 210A, a second light source 210B different from the first light source 210A, and an exchange mechanism 212 that exchanges the first light source 210A and the second light source 210B. For example, the first light source 210A is a light source that emits light in which the region with a wavelength of less than 330 nm among ultraviolet rays and visible light is attenuated. For example, the second light source 210B is a light source that emits light including both ultraviolet rays and visible light (light in which the region with a wavelength of less than 330 nm is not attenuated). For example, the exchange mechanism 212 may be a robot mechanism including a robot hand capable of gripping the first light source 210A or the second light source 210B and a robot arm capable of moving the robot hand.

[0111] For example, before the first irradiation step, the exchange mechanism 212 attaches the first light source 210A to the support opening 42a of the light source support portion 42. Thereby, in the first irradiation step, since the light from the first light source 210A is irradiated onto the substrate 2, the prepattern on the substrate can be irradiated with light in which the region with a wavelength of less than 330 nm among ultraviolet rays and visible light is attenuated (preferably light including a region with a wavelength of 350 nm or more and 450 nm or less).

[0112] For example, after the first irradiation step and before the second irradiation step, the exchange mechanism 212 attaches the second light source 210B to the support opening 42a of the light source support portion 42. That is, the exchange mechanism 212 exchanges the first light source 210A for the second light source 210B before the second irradiation step. As a result, in the second irradiation step, since the light from the second light source 210B irradiates the substrate 2, it is possible to irradiate the pre-pattern on the substrate with light including both ultraviolet light and visible light. For example, in the second irradiation step, it is preferable to irradiate the pre-pattern with light including a region having a wavelength of 200 nm or more and 600 nm or less among ultraviolet light and visible light (light in which regions having a wavelength of less than 200 nm and more than 600 nm among ultraviolet light and visible light are attenuated).

[0113] As described above, according to the present embodiment, in the first irradiation step, by providing the first light source 210A that emits light in which a region having a wavelength of less than 330 nm among ultraviolet light and visible light is attenuated, the pre-pattern is irradiated with light in which a region having a wavelength of less than 330 nm among ultraviolet light and visible light is attenuated. In the second irradiation step, by providing a second light source 210B different from the first light source 210A instead of the first light source 210A, the pre-pattern is irradiated with light including both ultraviolet light and visible light, thereby achieving the following effects. Since it is only necessary to exchange the light sources 210A and 210B between the first irradiation step and the second irradiation step, the replacement work becomes easier as compared with the case of replacing the optical filter.

[0114] In the light irradiation device 201 of the present embodiment, the light irradiation unit 203 includes a first light source 210A that emits light in which a region having a wavelength of less than 330 nm among ultraviolet light and visible light is attenuated, a second light source 210B different from the first light source 210A, and an exchange mechanism 212 that exchanges the first light source 210A and the second light source 210B. In the first irradiation control, by providing the first light source 210A, the substrate 2 is irradiated with light in which a region having a wavelength of less than 330 nm among ultraviolet light and visible light is attenuated. In the second irradiation control, by providing the second light source 210B instead of the first light source 210A, the substrate 2 is irradiated with light including both ultraviolet light and visible light.

[0115] <Third Embodiment> Next, a third embodiment of the present invention will be described with reference to FIG. 11. FIG. 11 is a plan view of a substrate processing apparatus 300 according to the third embodiment. In FIG. 11, components having the same configuration as those in the above-described embodiments are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0116] As shown in FIG. 11, the substrate processing apparatus 300 includes a coating apparatus 360 that applies a resist film containing a resist composition to the substrate 2, an exposure apparatus 361 that exposes the resist film applied to the substrate 2, a developing apparatus 362 that patterns the exposed resist film by development to form a pre-pattern, and a light irradiation apparatus 301 that irradiates one or both of ultraviolet light and visible light to cure the pre-pattern. The coating apparatus 360, the exposure apparatus 361, the developing apparatus 362, and the light irradiation apparatus 301 are arranged in order in the conveyance direction of the substrate 2.

[0117] The substrate processing apparatus 300 further includes a conveyance apparatus 363 for conveying the substrate 2 and a control apparatus 364 for comprehensively controlling each part of the substrate processing apparatus 300. For example, the conveyance apparatus 363 may include a robot mechanism including a robot hand capable of gripping the substrate 2 and a robot arm capable of moving the robot hand.

[0118] The coating apparatus 360 is an apparatus that applies a resist film to the substrate 2. For example, examples of the coating apparatus 360 include a rotary coating apparatus, a non-spin coating apparatus, and a slit nozzle coating apparatus. Note that a standby apparatus 365 for waiting for the substrate 2, a cleaning apparatus 366 for cleaning the substrate 2, a dehydration apparatus 367 for dehydrating the substrate 2, etc. may be provided on the -X side of the coating apparatus 360.

[0119] The exposure apparatus 361 is arranged on the +X side of the coating apparatus 360. The exposure apparatus 361 is an apparatus that exposes the resist film applied to the substrate 2. Note that a pre-bake processing apparatus 368 for performing a pre-bake process on the substrate 2 may be provided on the -X side of the exposure apparatus 361.

[0120] The developing device 362 is arranged on the -X side of the exposure device 361. The developing device 362 is a device that performs the developing process of the substrate after exposure. Note that a conveying mechanism 369 such as a belt conveyor may be provided on the +X side of the developing device 362.

[0121] The light irradiation device 301 is arranged on the -X side of the developing device 362. For example, as the light irradiation device 301, it is possible to provide the light irradiation device 1 (see FIG. 1) of the first embodiment or the light irradiation device 201 (see FIG. 10) of the second embodiment described above. Note that a post-baking processing device 370 that performs post-baking processing on the substrate 2 may be provided on the -X side of the light irradiation device 301.

[0122] As described above, the substrate processing device 300 of the present embodiment includes a coating device 360 that coats the substrate 2 with a resist film containing a resist composition, an exposure device 361 that exposes the resist film coated on the substrate 2, a developing device 362 that patterns the exposed resist film by development to form a prepattern, and a light irradiation device 301 that irradiates one or both of ultraviolet light and visible light to cure the prepattern. According to the present embodiment, by providing the light irradiation device 1 (see FIG. 1) or the light irradiation device 201 (see FIG. 10) described above as the light irradiation device 301, a resist pattern excellent in heat resistance can be formed in a short time.

[0123] <Fourth Embodiment> Next, the fourth embodiment of the present invention will be described with reference to FIG. 12. In the fourth embodiment, the arrangement of the light irradiation unit is particularly different from that of the first embodiment. In FIG. 12, the same reference numerals are given to the same configurations as those in the first embodiment, and the detailed description thereof is omitted. FIG. 12 is a cross-sectional view of a light irradiation device 401 used in the method for forming a resist pattern according to the fourth embodiment.

[0124] As shown in FIG. 12, the light irradiation device 401 includes a chamber 420 and a light irradiation unit 403 provided outside the chamber 420. The chamber 420 is configured to be able to accommodate the substrate 2 in a sealed space. A heating mechanism 430 for heating the substrate 2 is provided in the chamber 420. The heating mechanism 430 has a rectangular plate shape with substantially the same plan view size as the substrate 2. The heating mechanism 430 is arranged to support the substrate 2 from below. The heating mechanism 430 is attached to a stage 431. The heating mechanism 430 includes a heater (not shown) and the like.

[0125] A transmission part 423 that can transmit light from the light sources 410A and 410B is provided on the top plate of the chamber 420. For example, the transmission part 423 is formed of quartz, heat-resistant glass, a resin sheet, a resin film, or the like.

[0126] A lifting mechanism 460 that can move the substrate 2 in the Z direction is provided below the chamber 420. The lifting mechanism 460 has a plurality of lift pins 461 extending in the Z direction. A plurality of insertion holes through which the lift pins 461 can be inserted are provided in the stage 431, the bottom plate of the chamber 420, and the heating mechanism 430. The lift pins 461 can move in the Z direction within the chamber 420 while supporting the substrate 2 accommodated in the chamber 420. In the example of FIG. 12, the tips of the plurality of lift pins 461 are in contact with the lower surface of the substrate 2 through the respective insertion holes, and the state where the substrate 2 is separated upward from the heating mechanism 430 is shown by the upward movement of the plurality of lift pins 461. Note that a drive source 462 for raising and lowering the plurality of lift pins 461 in the lifting mechanism 460 is arranged outside the chamber 420.

[0127] The light irradiation unit 403 includes a first light source 410A, a second light source 410B different from the first light source 410A, and a transport mechanism 412 for moving the first light source 410A and the second light source 410B. For example, the first light source 410A is a light source that emits light with attenuation in the region where the wavelength is less than 330 nm among ultraviolet light and visible light. For example, the second light source 410B is a light source that emits light including both ultraviolet light and visible light (light that has not been attenuated in the region where the wavelength is less than 330 nm).

[0128] The transfer mechanism 412 includes a rail 413 extending in the X direction and two gantry frames 414A and 414B slidable along the rail 413. A pair of rails is provided so as to sandwich the chamber from both sides in the Y direction. The gantry frames 414A and 414B are formed in a gantry shape so as to straddle the chamber 420 in the Y direction. The gantry frames 414A and 414B have recesses that are recessed upward so as to be able to hold the light sources 410A and 410B. The light sources 410A and 410B are accommodated in the recesses. Portions of the light sources 410A and 410B other than the irradiation surfaces (lower surfaces) are covered by the wall portions of the gantry frames 414A and 414B that form the recesses.

[0129] For example, the gantry frames 414A and 414B are formed by members that shield the light from the light sources 410A and 410B. Thereby, when irradiating light from the light sources 410A and 410B, it is possible to avoid the light from diffusing laterally of the gantry frames 414A and 414B, and the light from the light sources 410A and 410B can be irradiated downward (onto the substrate 2 in the chamber 420). In the example of FIG. 12, a state is shown in which the first light source 410A held by the gantry frame 414A is disposed directly above the transmission portion 423.

[0130] For example, before the first irradiation step, the transfer mechanism 412 moves the gantry frames 414A and 414B holding the light sources 410A and 410B along the rail 413 and disposes the first light source 410A directly above the transmission portion 423. Thereby, in the first irradiation step, since the light from the first light source 410A is irradiated onto the substrate 2, it is possible to irradiate the prepattern on the substrate with light having attenuated the region of ultraviolet rays and visible light with a wavelength of less than 330 nm (preferably light including a region with a wavelength of 350 nm or more and 450 nm or less).

[0131] For example, before the second irradiation process and after the first irradiation process, the transport mechanism 412 moves the portal frames 414A and 414B that hold the light sources 410A and 410B along the rail 413, and arranges the second light source 410B directly above the transmission part 423. That is, before the second irradiation process, the transport mechanism 412 arranges the second light source 410B directly above the transmission part 423. Thereby, in the second irradiation process, since the light from the second light source 410B irradiates the substrate 2, it is possible to irradiate the prepattern on the substrate with light including both ultraviolet rays and visible light. For example, in the second irradiation process, it is preferable to irradiate the prepattern with light including a region of ultraviolet rays and visible light having a wavelength of 200 nm or more and 600 nm or less (light obtained by attenuating regions of ultraviolet rays and visible light having a wavelength of less than 200 nm and more than 600 nm).

[0132] As described above, according to the present embodiment, in the first irradiation process, by arranging the first light source 410A that emits light obtained by attenuating a region of ultraviolet rays and visible light having a wavelength of less than 330 nm directly above the transmission part 423, the prepattern is irradiated with light obtained by attenuating a region of ultraviolet rays and visible light having a wavelength of less than 330 nm. In the second irradiation process, by arranging a second light source 410B different from the first light source 410A directly above the transmission part 423, the prepattern is irradiated with light including both ultraviolet rays and visible light, thereby achieving the following effects. Since it is only necessary to move the light sources 410A and 410B between the first irradiation process and the second irradiation process, the work becomes easier compared to the case of replacing the optical filter.

[0133] In the light irradiation device 401 of the present embodiment, the light irradiation unit 403 includes a first light source 410A that emits light obtained by attenuating a region of ultraviolet rays and visible light having a wavelength of less than 330 nm, a second light source 410B different from the first light source 410A, and a transport mechanism 412 that moves the first light source 410A and the second light source 410B. In the first irradiation control, the substrate 2 is irradiated with light obtained by attenuating a region of ultraviolet rays and visible light having a wavelength of less than 330 nm by arranging the first light source 410A directly above the transmission part 423. In the second irradiation control, the substrate 2 is irradiated with light including both ultraviolet rays and visible light by arranging the second light source 410B directly above the transmission part 423.

[0134] <Modification Example> In addition, the various shapes, combinations, etc. of the respective constituent members shown in the above-described examples are merely examples, and can be variously changed based on design requirements and the like. For example, the present invention may be applied to a substrate processing system including the light irradiation device or the substrate processing device of the above-described embodiment. For example, the substrate processing system is a system that is incorporated and used in a manufacturing line such as a factory, and forms a thin film in a predetermined region of a substrate. Although not shown, for example, the substrate processing system includes a substrate processing unit including the above-described light irradiation device or substrate processing device, a substrate loading unit that is supplied with a loading cassette containing a substrate before processing and in which an empty loading cassette is recovered, a substrate unloading unit that is recovered with an unloading cassette containing a substrate after processing and in which an empty unloading cassette is supplied, a transport unit that transports the loading cassette between the substrate processing unit and the substrate loading unit and transports the unloading cassette between the substrate processing unit and the substrate unloading unit, and a control unit that comprehensively controls each unit. According to this configuration, by including the above-described light irradiation device or substrate processing device, a resist pattern excellent in heat resistance can be formed in a short time in the substrate processing system.

[0135] In addition, the respective constituent elements described as the embodiment or its modification example above can be appropriately combined within the scope not departing from the gist of the present invention, and also, some of the plurality of combined constituent elements can be appropriately not used.

Example

[0136] Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to the following examples.

[0137] The resist composition (1) used in this example is shown below. Resist composition (1): 100 parts by mass of the following alkali-soluble resin, 10 parts by mass of a sensitivity improver, and 23 parts by mass of a photosensitive component were uniformly dissolved in 429 parts by mass of an organic solvent, and then this was filtered using a membrane filter with a pore size of 0.2 μm to prepare a resist composition.

[0138] Alkali-soluble resin: A cresol novolak resin having a mass average molecular weight (Mw) of 4000, obtained by adding oxalic acid and formaldehyde to a mixture of 35 mol% of m-cresol and 65 mol% of p-cresol and subjecting them to a condensation reaction, and then subjected to a fractionation treatment, a cresol novolak resin with Mw = 4500 and a binuclear body content of phenols of about 6 mol% was used. Sensitivity improver: A phenol compound represented by the following chemical formula (V). Photosensitive component: An esterified product (esterification rate 59 mol%) of 1 mol of the compound represented by the following chemical formula (VIII) and 2.34 mol of 1,2-naphthoquinonediazide-5-sulfonic acid chloride (hereinafter referred to as "5-NQD"). Organic solvent: Propylene glycol monomethyl ether acetate.

[0139]

Chemical formula

[0140] <Evaluation> Using the above resist composition (1), a resist pattern was formed as follows, and each evaluation was performed.

[0141] [Formation of resist pattern] (Example 1) Process (1): The resist composition (1) was applied onto a 6-inch silicon wafer treated with hexamethyldisilazane (HMDS) using a spinner, and pre-baked on a hot plate at 110 °C for 90 seconds to dry, thereby forming a resist film with a thickness of 2.5 μm. Subsequently, it was exposed through a predetermined mask pattern using an exposure apparatus (trade name G7E, manufactured by Nikon Corporation; NA 0.54). Thereafter, alkali development was performed with a 2.38 mass% aqueous solution of tetramethylammonium hydroxide at 23 °C for 65 seconds. As a result, a line & space pre-pattern was formed.

[0142] Process (2): Next, the above pre-pattern was irradiated with light containing both ultraviolet and visible light to cure the pre-pattern. Process (2) was carried out by a first irradiation step of irradiating the pre-pattern with light in which the region with a wavelength less than 330 nm among ultraviolet and visible light (including light in the region of 350 nm or more and 450 nm or less based on a wavelength of 365 nm) was attenuated, and a second irradiation step of irradiating the pre-pattern with light in which the region with a wavelength less than 230 nm among ultraviolet and visible light (including light in the region of 230 nm or more and 600 nm or less based on a wavelength of 254 nm) was attenuated after the first irradiation step. The conditions for curing by such light irradiation are shown below. Apparatus: Ultraviolet irradiation apparatus (manufactured by Tokyo Ohka Kogyo Co., Ltd.). Light source: 160 W / cm high-pressure mercury lamp Irradiation window: Natural quartz window with a thickness of 25 mm Irradiation time: 180 seconds Temperature when curing the pre-pattern (temperature of the pre-pattern itself): 100 °C. A thermocouple was installed on the substrate stage and measured during irradiation with the cut-off light. Heating temperature of the substrate stage: Adjusted to 100 °C. Atmosphere in the apparatus: N2 gas was supplied, dew point -35 °C (moisture concentration 600 ppm by mass), oxygen concentration 1000 ppm by mass. Note that the temperature of the prepattern itself is determined by heating with a substrate stage (hot plate) and heating by radiation of light irradiation. Under the conditions of curing by such light irradiation, due to the mutual influence of the temperature drop due to heat absorption by the substrate and the temperature rise due to radiation of light irradiation, the temperature of the prepattern itself becomes near the heating temperature of the substrate stage. Further, in the first irradiation step, a band-pass filter that attenuates light in a region with a wavelength of less than 330 nm was provided for the light source. In the second irradiation step, the band-pass filter was removed from the light source. In Example 1, the irradiation time of the first irradiation step was 10 seconds, and the irradiation time of the second irradiation step was 170 seconds.

[0143] In Example 1, by steps (1) and (2), a resist pattern of line & space with a line width of 1.5 μm and a pitch width of 3.0 μm was obtained.

[0144] (Examples 2 to 4) The same operations as in Example 1 (steps (1) and (2)) were performed except that the irradiation time of the first irradiation step and the irradiation time of the second irradiation step were changed, and a resist pattern was obtained. In Example 2, the irradiation time of the first irradiation step was 30 seconds, and the irradiation time of the second irradiation step was 150 seconds. In Example 3, the irradiation time of the first irradiation step was 60 seconds, and the irradiation time of the second irradiation step was 120 seconds. In Example 4, the irradiation time of the first irradiation step was 120 seconds, and the irradiation time of the second irradiation step was 60 seconds.

[0145] (Comparative Example 1) Step (1): Using the resist composition (1), in the same manner as in Example 1, a line & space prepattern was obtained.

[0146] Step (2): Next, the obtained prepattern was irradiated with light containing both ultraviolet light and visible light (with the band-pass filter removed from the light source) to cure the prepattern. The conditions for curing by such light irradiation are shown below. Apparatus: Ultraviolet irradiation apparatus (manufactured by Tokyo Ohka Kogyo Co., Ltd.). Light source: 160 W / cm high-pressure mercury lamp Irradiation window: Natural quartz window with a plate thickness of 25 mm Irradiation time: 250 seconds Temperature when curing the prepattern (temperature of the prepattern itself): 100 °C. A thermocouple was installed on the substrate stage and measured during the irradiation of the cutting light. Heating temperature of the substrate stage: Adjusted to 100 °C. Atmosphere inside the apparatus: N2 gas was supplied, dew point -35 °C (moisture concentration 600 ppm by mass), oxygen concentration 1000 ppm by mass. Note that the temperature of the prepattern itself is determined by the heating by the substrate stage (hot plate) and the heating by the radiation of the light irradiation. Under the conditions of such light irradiation curing, due to the mutual influence of the temperature decrease due to the heat absorption by the substrate and the temperature increase due to the radiation of the light irradiation, the temperature of the prepattern itself becomes near the heating temperature of the substrate stage.

[0147] In Comparative Example 1, by the above-described operation, a resist pattern of line & space with a line width of 1.5 μm and a pitch width of 3.0 μm was obtained.

[0148] [Evaluation of heat resistance] The states (states after light irradiation) of the resist patterns obtained in Examples 1 to 4 and Comparative Example 1 were observed. Further, the silicon wafers on which the respective resist patterns were formed were placed on a hot plate at each temperature of 150 °C and 160 °C and heated for 5 minutes each. Then, the states of the respective resist patterns after heating were observed and the heat resistance was evaluated. The evaluation results of such heat resistance are shown in Table 1. Note that the evaluation was based on the following evaluation criteria. Evaluation criteria 5 points: The entire surface was mirror-like and no wrinkles or the like were observed at all. 3 points: No wrinkles were observed, but slight lifting was observed partially. 2 points: Lifting was observed partially. 1 point: Wrinkles were observed partially. 0 points: Wrinkles were observed over the entire surface.

[0149]

Table 1

[0150] As a result, in the state after heating the resist patterns obtained in Examples 2 to 4, overall wrinkles and partial wrinkles that were not observed in the resist patterns obtained in Comparative Example 1 and Example 1 were observed. From this, it was confirmed that the resist pattern obtained in Example 1 has higher heat resistance than the resist patterns obtained in Examples 2 to 4. As a result, it can be considered that the entire resist pattern obtained in Example 1 is sufficiently cured up to its interior, and it can be said that the dry etching resistance is also high. Furthermore, it was confirmed that the heat resistance of the resist pattern obtained in Example 1 is not inferior to the heat resistance of the resist pattern obtained in Comparative Example 1. From the above, it was found that the conditions of the first irradiation step and the second irradiation step of Example 1 are conditions that can form a resist pattern excellent in heat resistance in a short time.

Explanation of symbols

[0151] 1,201,301,401… Light irradiation device 2… Substrate 3,203,403… Light irradiation unit 4… Control unit 10… Light source 11… Optical filter 12… Detachable mechanism 210A,410A… First light source 210B,410B… Second light source 212… Exchange mechanism 300… Substrate processing apparatus 360… Coating apparatus 361… Exposure apparatus 362… Developing apparatus

Claims

1. An optical irradiation device for curing a prepattern formed by exposing and developing a resist film on a substrate, comprising: a chamber in which an accommodation space capable of accommodating the substrate is formed, and the accommodation space is adjusted to a predetermined gas atmosphere; a control unit; a light source for irradiating light; a first optical filter that is attachable to and detachable from the light source and attenuates light in a first wavelength band for curing the surface layer portion of the prepattern; and the control unit: performs first irradiation control for directly irradiating the substrate with light from the light source in the gas atmosphere with the first optical filter attached to the light source to suppress curing of the surface layer portion of the prepattern; after the first irradiation control, performs second irradiation control for directly irradiating the substrate with light from the light source in the gas atmosphere with the first optical filter detached from the light source. An optical irradiation device.

2. The optical irradiation device according to claim 1, wherein the light source irradiates one or both of ultraviolet light and visible light.

3. The optical irradiation device according to claim 1 or 2, wherein the light in the first wavelength band is light in a wavelength band less than 330 nm.

4. The optical irradiation device according to any one of claims 1 to 3, wherein the second irradiation control irradiates the substrate with light from the light source with a second optical filter attached that attenuates light in a second wavelength band less than 230 nm.

5. The optical irradiation device according to any one of claims 1 to 4, further comprising an attachment / detachment mechanism for attaching and detaching an optical filter to and from the light source. The control unit controls the attachment / detachment mechanism. The optical irradiation device according to any one of claims 1 to 4.

6. An optical irradiation device for curing a prepattern formed by exposing and developing a resist film on a substrate, comprising: a chamber in which an accommodation space capable of accommodating the substrate is formed, and the accommodation space is adjusted to a predetermined gas atmosphere; a control unit; an optical irradiation unit including a light source for irradiating light; and the optical irradiation unit includes, as the light source: a first light source that irradiates light with light in a first wavelength band for curing the surface layer portion of the prepattern attenuated; a second light source that irradiates light including all or part of the light in the first wavelength band; and the control unit: performs first irradiation control for directly irradiating the substrate with light from the first light source in the gas atmosphere to suppress curing of the surface layer portion of the prepattern; after the first irradiation control, performs second irradiation control for directly irradiating the substrate with light from the second light source in the gas atmosphere. An optical irradiation device.

7. The light irradiation device according to claim 6, wherein the first light source and the second light source irradiate one or both of ultraviolet light and visible light.

8. The light irradiation device according to claim 6 or 7, wherein the light in the first wavelength band is light in a wavelength band of less than 330 nm.

9. The light irradiation device according to any one of claims 6 to 8, wherein the second light source irradiates light in which light in a second wavelength band of less than 230 nm is attenuated.

10. The light irradiation unit includes an exchange mechanism that exchanges the first light source and the second light source, The control unit controls the exchange mechanism, and the light irradiation device according to any one of claims 6 to 9.

11. A coating device that coats the substrate with a resist to form the resist film; An exposure device that exposes the resist film; A developing device that develops the exposed resist film to form the prepattern; A substrate processing apparatus comprising the light irradiation device according to any one of claims 1 to 10.

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