Substrate processing apparatus

Abstract

In the case of forming a fine resist pattern, it is desired to further reduce the roughness of the resist pattern.SOLUTION: A substrate processing apparatus comprising: a heat treatment unit configured to bake a resist film; an exposure unit configured to irradiate the resist film having a portion irradiated with a first radioactive ray with a second radioactive ray; a development unit configured to form a resist pattern by development for removing a part of the resist film; and a control unit configured to control the exposure unit such that the second radioactive ray is collectively irradiated to an entire region of the resist film including the portion irradiated with the first radioactive ray and a portion other than the portion irradiated with the first radioactive ray. The first radiation is ionizing radiation or non-ionizing radiation, and the second radiation is non-ionizing radiation. When the first radiation is non-ionizing radiation, the second radiation is non-ionizing radiation having a wavelength longer than the wavelength of the first radiation. The resist film includes a metal oxide photoresist material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a method for forming a resist pattern, a method for manufacturing a semiconductor device, a substrate processing apparatus, and a storage medium. [Background technology]

[0002] In order to form fine resist patterns with a size of 20 nm, extreme ultraviolet (EUV) lithography technology using chemically amplified resist materials has conventionally been applied (Patent Document 1). In the case of chemically amplified resist materials, the reaction for forming the resist pattern generally proceeds due to the action of an acid catalyst generated by pattern exposure. It has also been proposed to use non-chemically amplified resist materials to form fine resist patterns by EUV lithography (Patent Document 2 and Non-Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-101593 [Patent Document 2] U.S. Patent Application Publication No. 2020 / 0064733 [Non-patent literature]

[0004] [Non-Patent Document 1] J. Micro / Nanolith. MEMS MOEMS 16(2), 023510 (Apr-Jun 2017) Summary of the Invention [Problem to be solved by the invention]

[0005] When forming a fine resist pattern, it is desirable to further reduce the roughness of the resist pattern. [Means for solving the problem]

[0006] One aspect of the present disclosure relates to a method for forming a resist pattern, the method comprising, in this order, irradiating a portion of a resist film containing a resist material with a first radiation, baking the resist film, collectively irradiating an entire region of the resist film, including the portion irradiated with the first radiation and other portions, with a second radiation, and forming a resist pattern by developing to remove a portion of the resist film, wherein the first radiation is ionizing radiation or non-ionizing radiation, the second radiation is non-ionizing radiation, and when the first radiation is non-ionizing radiation, the second radiation is non-ionizing radiation having a wavelength longer than that of the first radiation. [Effects of the Invention]

[0007] According to the method of the present disclosure, it is possible to reduce the roughness of a fine resist pattern formed by extreme ultraviolet (EUV) lithography or the like. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a flowchart illustrating an example of a method for forming a resist pattern. [Figure 2] 1A to 1C are process diagrams illustrating an example of a method for manufacturing a semiconductor device by a method including forming a resist pattern. [Figure 3] 1A to 1C are process diagrams illustrating an example of a method for manufacturing a semiconductor device by a method including forming a resist pattern. [Figure 4] 1A to 1C are process diagrams illustrating an example of a method for manufacturing a semiconductor device by a method including forming a resist pattern. [Figure 5] 1 is a flowchart illustrating an example of a method for forming a resist pattern. [Figure 6] FIG. 1 is a schematic view showing an example of a substrate processing apparatus. [Figure 7] FIG. 1 is a schematic view showing an example of a substrate processing apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described in order to explain the present invention. However, the present invention should not be limited to the following contents. In the following description, the same elements or elements having the same functions are designated by the same reference numerals, and redundant description may be omitted.

[0010] FIG. 1 is a flowchart showing an example of a method for forming a resist pattern, and FIGS. 2, 3, and 4 are process diagrams showing an example of a method for forming a resist pattern and a method for manufacturing a semiconductor device that includes forming a resist pattern by that method.

[0011] 1 to 4 includes, in this order, a step S10 of applying a photoresist composition to a film 3 to be etched provided on a semiconductor wafer 1, a step S11 of baking the applied photoresist composition to form a resist film 5, a patternwise exposure step S20 of irradiating a portion (5E) of the resist film 5 with a first radiation R1, a post-exposure bake step S30 of baking the resist film 5 after patternwise exposure, a floodwise exposure step S40 of irradiating the entire region of the resist film 5, including the portion 5E irradiated with the first radiation R1 and other portions, with a second radiation R2, and a development step S50 of developing and removing a portion of the resist film 5 to form a resist pattern 5A having trenches 5a exposing the film 3 to be etched. The first radiation R1 is ionizing radiation or non-ionizing radiation, and the second radiation R2 is non-ionizing radiation. When the first radiation R1 is non-ionizing radiation, the second radiation R2 is non-ionizing radiation having a wavelength longer than that of the first radiation.

[0012] The resist film 5 includes a resist material. The photoresist composition used to form the resist film 5 includes a resist material and a solvent. The resist material can be, for example, a metal oxide photoresist material or a chemically amplified photoresist material.

[0013] The metal oxide photoresist material may include, for example, an organometallic compound containing a metal oxide containing a metal atom and an organic ligand bonded to the metal atom. The metal oxide photoresist material may be nanoparticles (particles with a maximum width of less than 1 μm). The metal oxide may be a cage compound. The metal oxide photoresist material containing an organometallic compound is thought to form a crosslinked structure through a reaction that includes detachment of the organic ligand from the metal atom upon irradiation with the first radiation R1 and bonding of the metal atoms from which the organic ligand has been detached via an oxygen atom or the like through a condensation reaction. The formed crosslinked structure is substantially insoluble in a developer, allowing the metal oxide photoresist material to function as a negative resist material. When the metal oxide photoresist material is nanoparticles, multiple nanoparticles may link together to form aggregates that are substantially insoluble in a developer. These aggregates are thought to be formed mainly during the post-exposure bake (step S30). After post-exposure baking, floodwise exposure with second radiation R2 (step S40) changes the solubility in a developer of portions of resist film 45 other than portion 5E irradiated with first radiation R1. This is thought to be because second radiation R2 converts metal oxides into metal hydroxides, thereby increasing the hydrophilicity (polarity) of the resist film. The increase in dissolution contrast during development of the resist due to the change in the solubility of the resist film caused by second radiation R2 is thought to contribute to reducing the roughness of the formed resist pattern.

[0014] The metal oxide of the metal oxide photoresist material may contain at least one metal atom selected from the group consisting of Sn, Sb, In, Ti, Zr, Hf, V, Co, Mo, W, Al, Ga, Si, Ge, P, As, Y, La, Ce, and Lu. The organic ligand bonded to the metal atom of the metal oxide may be, for example, an optionally substituted branched or unbranched alkyl group or an optionally substituted cycloalkyl group. The alkyl group and cycloalkyl group may be bonded to the metal atom at a primary, secondary, or tertiary carbon atom. The alkyl group and cycloalkyl group may have 1 to 30 carbon atoms. Examples of the alkyl group as the organic ligand include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, and an n-octyl group. Examples of the cycloalkyl group as the organic ligand include a cyclobutyl group, a cyclopropyl group, a cyclohexyl group, a 1-adamantyl group, and a 2-adamantyl group. Examples of the substituents that the alkyl and cycloalkyl groups may have include a cyano group, an alkylthio group, a silyl group, an alkyloxy group, an alkylcarbonyl group, an alkylcarbonylyl group, and a halogeno group. Nanoparticles containing cage-shaped tin oxide and organic ligands can be prepared, for example, by the formula: [(SnR) 12 O 14 (OH)6](OH)2 (R represents an organic ligand).

[0015] The chemically amplified photoresist material forming the resist film 5 may include a polymer component that becomes soluble or insoluble in a developer under the action of acid and an acid generator that generates acid upon exposure to first radiation R1. The chemically amplified photoresist material includes, as one or more components selected from the polymer component, the acid generator, and other components, a sensitizer precursor component that increases the absorption of second radiation R2 by the resist material upon exposure to first radiation R1. In the portion 5E of the resist film 5 irradiated with first radiation R1, the action of the acid generated from the acid generator changes the solubility of the polymer component, and a component that absorbs second radiation R2 is generated from the sensitizer precursor component. The generation of the component that absorbs second radiation R2 allows the portion 5E irradiated with first radiation R1 to selectively absorb second radiation R2. As a result, the solubility of the resist in the exposed portion increases due to decomposition of the acid generator by second radiation R2 in the portion 5E irradiated with first radiation R1, thereby increasing the development contrast and, presumably, reducing the roughness of the resist pattern.

[0016] The polymer component, the acid generator, or both of these contained in the chemically amplified photoresist material may be partly or entirely a compound that functions as a sensitizer precursor component. When the chemically amplified photoresist material contains a quencher, which is a compound that neutralizes the acid generated from the acid generator, partly or entirely of the quencher may be a compound that functions as a sensitizer precursor component. The chemically amplified photoresist material may also contain a compound other than the polymer component, the acid generator, and the quencher as a sensitizer precursor component. The sensitizer precursor component may be a component that increases the absorption of the second radiation R2 by the resist film 5 by absorbing the first radiation R1.

[0017] The sensitizer precursor component can be, for example, a precursor compound that generates a sensitizer having a carbonyl group, or a polymer component, acid generator, or quencher that includes a partial structure derived from the precursor compound. Examples of the precursor compound include acetal compounds, ketal compounds, thioacetal compounds, alcohol compounds, thiol compounds, and orthoester compounds. Compounds (e.g., ketone compounds) generated from these precursor compounds by the action of an acid generally absorb the second radiation, thereby increasing the absorption of the second radiation by the resist film.

[0018] The acetal compound, ketal compound, and thioacetal compound that can be used as a precursor compound may be, for example, a compound represented by the following formula (1), which is converted into a ketone compound represented by formula (1A) by the action of an acid.

[0019] [ka]

[0020] In formulas (1) and (1A), Z 1 represents an oxygen atom or a sulfur atom, and R 1 represents an aryl group (e.g., a phenyl group, a naphthyl group, or an anthracenyl group) which may have a substituent, or a conjugated diene group which may have a substituent, and R 2 represents a hydrogen atom, a halogen atom, an aryl group which may have a substituent (for example, a phenyl group, a naphthyl group, or an anthracenyl group), a conjugated diene group which may have a substituent, a hydrocarbon group having 1 to 30 or 1 to 5 carbon atoms (for example, an alkyl group) which may have a substituent, an alkanoyl group having an alkyl group having 1 to 12 carbon atoms which may have a substituent, an amino group, or an aminocarbonyl group; R 3 and R 4 R each independently represents a hydrocarbon group having 1 to 30 carbon atoms or 1 to 5 carbon atoms (for example, an alkyl group) which may have a substituent. 1 and R 2 may be bonded to each other directly or via a divalent group to form a cyclic structure, and R3 and R 4 may be bonded to each other directly or via a divalent group to form a cyclic structure.

[0021] R 1 ~R 4 Examples of the divalent group constituting a cyclic structure formed by the formula are -CH2-, -O-, -S-, -SO2-, -SONH-, -C(=O)-, -C(=O)O-, -NHCO-, -NHC(=O)NH-, -CHR A -, -CR A 2-, -NH- and -NR A -Includes. R A represents a phenyl group, a phenoxy group, a halogen atom, a hydrocarbon group having 1 to 30 carbon atoms or 1 to 5 carbon atoms (for example, an alkyl group), an alkoxy group having 1 to 5 carbon atoms, a hydroxyl group, or a phenoxy group substituted with an alkyl group having 1 to 5 carbon atoms, or a phenyl group substituted with a hydrocarbon group having 1 to 30 carbon atoms or 1 to 5 carbon atoms (for example, an alkyl group), an alkoxy group having 1 to 5 carbon atoms, or a hydroxyl group.

[0022] R 1 or R 2 Examples of the substituents that the aryl group and non-conjugated diene group as R may have include hydrocarbon groups having 1 to 30 or 1 to 5 carbon atoms (e.g., alkyl groups), hydroxyalkoxy groups having 1 to 5 carbon atoms, hydroxyalkyl groups having 1 to 5 carbon atoms, alkoxy groups having 1 to 5 carbon atoms which may have a substituent, amino groups, aminocarbonyl groups, and hydroxyl groups. 1 ~R 4 Examples of the substituent that the hydrocarbon group, alkanoyl group, and alkoxy group as the substituent may have include an alkoxy group having 1 to 5 carbon atoms, an alkoxycarbonyl group having an alkyl group having 1 to 5 carbon atoms, a cycloalkoxycarbonyl group having a cycloalkyl group having 5 to 30 carbon atoms, a furyl group, a phenoxy group, a naphthoxy group, an anthracenoxy group, an amino group, an aminocarbonyl group, and a hydroxyl group.

[0023] R 3 and R 4are alkyl groups directly bonded to each other, the acetal compound is represented by the following formula, for example: In these formulas, a substituent such as an alkyl group having 1 to 5 carbon atoms, a cycloalkyl group having 3 to 30 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an alkoxycarbonyl group having an alkyl group having 1 to 5 carbon atoms, a cycloalkoxycarbonyl group having a cycloalkyl group having 5 to 30 carbon atoms, a furyl group, a phenoxy group, a naphthoxy group, an anthracenoxy group, an amino group, an aminocarbonyl group, or a hydroxyl group may be bonded to the carbon atom constituting the cyclic structure.

[0024] [ka]

[0025] The alcohol compounds and thiol compounds that can be used as precursor compounds may be, for example, compounds represented by the following formula (2), which are converted into ketone compounds represented by formula (2A) by the action of an acid.

[0026] [ka]

[0027] In formula (2) and formula (2A), Z 1 represents an oxygen atom or a sulfur atom, and R 5 represents an optionally substituted aryl group (e.g., a phenyl group, a naphthyl group, or an anthracenyl group) or an optionally substituted conjugated diene group, and R 6 represents an aryl group which may have a substituent (for example, a phenyl group, a naphthyl group, or an anthracenyl group), a conjugated diene group which may have a substituent, a hydrocarbon group having 1 to 30 carbon atoms or 1 to 5 carbon atoms (for example, an alkyl group) which may have a substituent, an alkanoyl group having an alkyl group having 1 to 12 carbon atoms which may have a substituent, an amino group, or an aminocarbonyl group; R 7 represents a hydrogen atom or a halogen atom, and R 8 indicates a hydrogen atom. 5 and R 6may be bonded to each other directly or via a divalent group to form a cyclic structure. 5 or R 6 The aryl group and the non-conjugated diene group as R 1 or R 2 R may have the same substituents as the aryl group and conjugated diene group may have. 5 and R 6 The divalent group constituting the cyclic structure formed by 1 ~R 4 It can be the same as the divalent group constituting the cyclic structure formed by:

[0028] The orthoester compound that can be used as the precursor compound may be, for example, a compound represented by formula (3) or (4), which is converted into an ester compound represented by formula (3A) or a carboxylic acid compound represented by formula (4A), respectively, by the action of an acid.

[0029] [ka]

[0030] In formulas (3) and (4), R 9 represents an aryl group (e.g., a phenyl group, a naphthyl group, or an anthracenyl group) which may have a substituent, and R 10 represents a hydrocarbon group (e.g., an alkyl group) having 1 to 30 carbon atoms or 1 to 5 carbon atoms which may have a substituent, and multiple R 10 may be the same or different. 9 Examples of the substituent that the aryl group as R may have include an alkyl group having 1 to 30 carbon atoms or 1 to 5 carbon atoms, an aryloxy group, an arylalkyl group having an alkyl group having 1 to 5 carbon atoms, an arylalkyloxy group having an alkyl group having 1 to 5 carbon atoms, a hydroxyalkoxy group having 1 to 5 carbon atoms, a hydroxyalkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an amino group, an aminocarbonyl group, and a hydroxyl group. 9The aryl group represented by R in formula (4) may contain two or more aromatic rings bonded to each other at two or more positions directly or via a divalent group. 11 represents a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms or 1 to 5 carbon atoms (e.g., an alkyl group) which may have a substituent, an aryl group (e.g., a phenyl group, a naphthyl group, or an anthracenyl group) which may have a substituent, an alkoxy group having 1 to 5 carbon atoms which may have a substituent, or an aryloxy group (e.g., a phenoxy group, a naphthoxy group, or an anthracenoxy group) which may have a substituent. 11 Examples of the substituent that may be possessed by the hydrocarbon group, aryl group, alkoxy group and aryloxy group as the substituent include an alkoxy group having 1 to 5 carbon atoms, an alkoxycarbonyl group having an alkyl group having 1 to 5 carbon atoms, a cycloalkoxycarbonyl group having a cycloalkyl group having 5 to 30 carbon atoms, a furyl group, a phenoxy group, a naphthoxy group, an anthracenoxy group, an amino group, an aminocarbonyl group, and a hydroxyl group.

[0031] More specific examples of ketal compounds that can be used as precursor compounds include compounds represented by the following formula (11) or (12):

[0032] [ka]

[0033] In formulas (11) and (12), R 3 and R 4 is R in equation (1). 3 and R 4 is defined similarly to R 12 and R 13 each independently represents a hydrocarbon group having 1 to 30 carbon atoms or 1 to 5 carbon atoms (for example, an alkyl group), a hydroxyalkoxy group having 1 to 5 carbon atoms, a hydroxyalkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms which may have a substituent, an amino group, an aminocarbonyl group, or a hydroxyl group, and two R 12 or R 13may be bonded to each other directly or via a divalent group to form a cyclic structure. m and n each independently represent an integer of 0 to 4, and multiple R 12 and R 12 may be the same or different. 2 -O-, -S- and -NR A - represents a divalent group selected from R A is the R A R is a group similar to 12 or R 13 Examples of the substituent that the alkoxy group may have include an alkyl group having 1 to 5 carbon atoms.

[0034] R 12 and R 13 may be a hydroxyalkoxy group having 1 to 5 carbon atoms, and two R 12 or two R's 13 are bonded to each other to form the following formula: [ka] R 14 represents an alkyl group having 1 to 5 carbon atoms. In this case, an example of the acetal compound is represented by the following formula (11a) or (11b). In formula (11a), R 15 and R 16 represents an alkyl group having 1 to 5 carbon atoms or a hydroxyalkyl group having 1 to 5 carbon atoms.

[0035] [ka]

[0036] The polymer component can be selected from common polymers that constitute chemically amplified photoresist materials. For example, the polymer component may be a polymer containing a monomer unit containing a group that generates a polar group upon the action of an acid. The monomer unit containing a group that generates a polar group upon the action of an acid is represented, for example, by the following formula (21) or (22). The polymer component that functions as a sensitizer precursor component may be a polymer that further contains a monomer unit containing a partial structure derived from the precursor compound described above.

[0037] [ka]

[0038] In formula (21), R 21 represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, and R 22 represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, and R 23 and R 24 each independently represents a linear or branched hydrocarbon group having 1 to 20 carbon atoms, or groups which combine with each other to form a cyclic hydrocarbon group having 3 to 20 members.

[0039] In formula (22), R 23 represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, and R 26 represents a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms; R 27 and R 28 each independently represents a monovalent hydrocarbon group having 1 to 20 carbon atoms or a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms; L 1 represents a single bond, -O-, -COO- or -CONH-. An oxyhydrocarbon group is a group having two or more hydrocarbon groups with oxy groups interposed between them.

[0040] The acid generator may include a sulfonium salt, an iodonium salt, or a combination thereof. The acid generator functioning as a sensitizer precursor component may be a sulfonium salt or an iodonium salt having a partial structure derived from the precursor compound described above. Examples of acid generators functioning as a sensitizer precursor component include compounds represented by the following formulas (31), (32), (33), or (34).

[0041] [ka]

[0042] In formulas (31) to (34), R 3 , R 4 , R 11 , R 12 and Z 2 is R in formula (11) or (12). 3 , R 4 , R 11 , R 12 and Z 2 is synonymous with.

[0043] R in formulas (31) and (32) 31 and R 32 R each independently represents any one selected from the group consisting of an optionally substituted linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms, an optionally substituted linear, branched, or cyclic alkenyl group having 1 to 12 carbon atoms, an optionally substituted aryl group having 6 to 14 carbon atoms, and an optionally substituted heteroaryl group having 4 to 12 carbon atoms. 31 , R 32 Any two or more of the aryl groups to which the sulfonium groups are bonded may form a ring structure together with the sulfur atom to which they are bonded, either directly via a single bond or via any group selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom-containing group, and a methylene group. 31 or R 32 At least one methylene group constituting the formula may be substituted with a divalent heteroatom-containing group.

[0044] R in formulas (33) and (34) 33 represents an aryl group which may have a substituent or a heteroaryl group which may have a substituent, and R 33 and the aryl group having an iodonium group bonded thereto may be bonded to each other to form a ring structure together with the iodine atom to which they are bonded.

[0045] In formulas (31) to (34), L 2 represents any one selected from the group consisting of a direct bond, a linear, branched, or cyclic alkylene group having 1 to 12 carbon atoms, an alkenylene group having 1 to 12 carbon atoms, an arylene group having 6 to 14 carbon atoms, a heteroarylene group having 4 to 12 carbon atoms, and groups in which these groups are bonded via an oxygen atom, a sulfur atom, or a nitrogen atom-containing group.

[0046] In formulas (31) to (34), X - represents a monovalent counter anion. X - Examples include sulfonate anions, carboxylate anions, imide anions, methide anions, carbonate anions, borate anions, halogen anions, phosphate anions, antimonate anions, and arsenate anions.

[0047] The quencher may include a sulfonium salt, an iodonium salt, or a combination thereof. The acid generator that functions as a sensitizer precursor component may be a sulfonium salt or an iodonium salt having a partial structure derived from the precursor compound described above.

[0048] The amount of the sensitizer precursor component (the amount of the precursor compound, or the amount of the partial structure derived from the precursor compound) in the photoresist composition or the pre-exposure resist film 5 formed therefrom may be, for example, 0.1 to 40 parts by mass, or 1 to 20 parts by mass, per 100 parts by mass of the chemically amplified resist material (or resist film 5).

[0049] The solvent constituting the photoresist composition used to form the resist film 5 is selected from those capable of dispersing or dissolving the resist material. Examples of the solvent include ketones such as cyclohexanone and methyl 2-amyl ketone; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; ethers such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; and esters such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, propylene glycol monomethyl ether acetate, and propylene glycol monotert-butyl ether acetate.

[0050] The amount of solvent in the photoresist composition is adjusted within a range that allows for the appropriate formation of resist film 5 by a method such as spin coating. For example, the amount of solvent may be 500 to 100,000 parts by mass per 100 parts by mass of the non-chemically amplified resist material.

[0051] The photoresist composition is applied onto the film 3 to be etched by, for example, spin coating (step S10). The applied photoresist composition is baked to remove the solvent in the photoresist composition (step S11). A pre-formed resist film 5 may be laminated on the film 3 to be etched. The thickness of the resist film 5 may be, for example, 1 to 5000 nm, 10 to 1000 nm, or 30 to 200 nm.

[0052] The formed resist film 5 is irradiated with first radiation R1 through a mask 7 having openings arranged on the resist film 5 (step S20). As a result, portions (5E) of the resist film 5 exposed in the openings of the mask 7 are irradiated with first radiation R1 having a pattern corresponding to the openings.

[0053] The first radiation R1 may be ionizing radiation or non-ionizing radiation having a wavelength of 300 nm or less. The light source of the first radiation R1 may be, for example, an electron beam of 1 keV to 200 keV, extreme ultraviolet (EUV) having a wavelength of about 13.5 nm, excimer laser light (ArF excimer laser light), or excimer laser light (KrF excimer laser light) of 193 nm. The dose of the first radiation R1 may be, for example, 5 to 300 mJ / cm. 2 The exposure to the first radiation R1 can be performed by immersion lithography or dry lithography. Instead of using a mask, the first radiation R1 may be irradiated in a predetermined pattern.

[0054] After irradiation with the first radiation R1, the mask 7 is removed and the resist film 5 is baked (step S30). Heating for baking after pattern exposure with the first radiation R1 can be performed in air or in an inert gas atmosphere such as nitrogen and argon. The heating temperature may be 50 to 250°C, and the heating time may be 10 to 300 seconds.

[0055] Next, the entire region of the resist film 5, including the portion 5E irradiated with the first radiation R1 and the other portions, is irradiated with the second radiation R2 (step S40, flood exposure). When the second radiation R2 is irradiated, the solubility in the developer of the portion 5E irradiated with the first radiation R1 is selectively changed.

[0056] The second radiation R2 may be non-ionizing radiation, and when the first radiation R1 is ionizing radiation, the second radiation R2 may have a wavelength longer than that of the first radiation R1. For example, the second radiation R2 may be ultraviolet light having a wavelength of 100 nm or more and 450 nm or less. The second radiation R2 may be ultraviolet light having a wavelength of 254 nm, 280 nm, 365 nm, 385 nm, or 395 nm. The light source of the second radiation R2 may be, for example, a mercury lamp, a xenon lamp, or an LED. The dose of the second radiation (e.g., ultraviolet light from an LED) may be, for example, 0.005 to 20 J / cm. 2 The exposure to the second radiation R2 can be carried out by immersion lithography or dry lithography.

[0057] Subsequently, a portion of the resist film 5 is removed by development, thereby forming a resist pattern 5A having trenches 5a that expose the film 3 to be etched (step S50, (f) of FIG. 4). If the resist film 5 is a negative resist, the portion 5E irradiated with the first radiation R1 does not substantially dissolve in the developer and remains as the resist pattern 5A. If the resist film 5 is a positive resist, contrary to the illustrated embodiment, the portion 5E irradiated with the first radiation R1 is removed, and the remaining portion remains as the resist pattern 5A.

[0058] Development can be by contact with a developer or by dry development.

[0059] The developer is selected from those that can efficiently dissolve the portion 5E irradiated with the first radiation R1 and other portions. The developer can be, for example, an organic developer or an alkaline developer.

[0060] When the resist material is a negative resist material (eg, a metal oxide photoresist material or a chemically amplified photoresist material), the developer may be an organic developer. Examples of organic developers include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, 2-heptanone, propylene glycol monomethyl ether acetate, isopropyl alcohol, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monoethyl ...propyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol Propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxy Dipentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate,Examples of suitable organic developers include ethyl 2-hydroxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, and propyl 3-methoxypropionate. The organic developer may be a mixture of these with an organic acid (acetic acid, citric acid, etc.). The organic developer may be butyl acetate, 2-heptanone, propylene glycol monomethyl ether acetate, or a mixture of these with an organic acid (acetic acid, citric acid, etc.). In the case of metal oxide photoresist materials, the hydrophilized portions in the unexposed areas may be removed by rinsing with water after development.

[0061] When the resist material is a negative resist material (e.g., a chemically amplified photoresist material), the developer may be an alkaline aqueous solution. The alkaline aqueous solution used as the developer may contain alkaline components such as inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia; primary amines such as ethylamine and n-propylamine; secondary amines such as diethylamine and di-n-butylamine; tertiary amines such as triethylamine and methyldiethylamine; alcohol amines such as dimethylethanolamine and triethanolamine; quaternary ammonium salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline; and cyclic amines such as pyrrole and piperidine. The alkaline aqueous solution may also contain alcohols such as isopropyl alcohol and nonionic surfactants. The developer may be an alkaline aqueous solution containing a quaternary ammonium salt, or tetramethylammonium hydroxide or tetrabutylammonium hydroxide. Rinsing after development may be performed using water or an organic-containing material.

[0062] FIG. 5 is a flowchart showing another example of a method for forming a resist pattern. The method shown in FIG. 5 includes a pre-development step (step S35) for preliminarily developing the resist film after post-exposure baking (step S30) and before flood-exposure with a second radiation (step S40). The developer for the pre-development can be development by contact with a developer or dry development. Pre-development can further improve sensitivity. Pre-development can be particularly effective for metal oxide photoresist materials, for example. Pre-development can be development with a developer, and development after flood-exposure can be development with a developer or dry development. The line width (CD) of the resist pattern after pre-development can be measured, and the dose of flood-exposure can be adjusted based on the measured line width.

[0063] In the method for forming a resist pattern, the resist pattern formed by development may be further exposed to ultraviolet light. This can further improve the durability of the resist pattern. The ultraviolet light source for exposure after development may be an LED or UV lamp that emits light having a peak between 160 nm and 420 nm. In the method for forming a resist pattern, the resist pattern formed by development may be baked.

[0064] The method for manufacturing a semiconductor device further includes a step of etching the film to be etched 3 exposed in the trenches 5a of the resist pattern 5A, thereby forming a patterned film to be etched 3A so as to form trenches 3a, as shown in (g) and (h) of FIG. 4. The method for etching the film to be etched 3 can be selected taking into consideration the type of material constituting the film to be etched 3, and may be, for example, dry etching or wet etching. After etching, the resist pattern 5A may be removed. The method illustrated in FIG. 4 provides a semiconductor wafer 1 and a processed substrate 10 having a patterned film to be etched 3A.

[0065] The patterned film to be etched 3A may be, for example, an active layer, a lower insulating film, a gate electrode film, or an upper insulating film. Wiring may be buried in the trenches 3a in the film to be etched 3A. The method according to the present disclosure can be used to manufacture a semiconductor device including, for example, an integrated circuit including a semiconductor substrate and a patterned film to be etched formed on the semiconductor substrate.

[0066] A lithography mask or a nanoimprint template can also be manufactured by etching using the resist pattern formed by the method according to the present disclosure as a mask. The lithography mask may be a transmission mask or a reflection mask.

[0067] For the above-exemplified method, for example, a substrate processing apparatus can be used that is mainly composed of a heat treatment unit that bakes a resist film formed on a workpiece having a film to be etched, an exposure unit that irradiates the resist film having a portion irradiated with the first radiation with the second radiation, a development unit that removes a portion of the resist film by development, thereby forming a resist pattern, and a control unit that controls the exposure unit so that the second radiation is irradiated all at once to the entire area of ​​the resist film, including the portion irradiated with the first radiation and the other portions.

[0068] 6 and 7 are schematic diagrams showing an example of a substrate processing apparatus. FIG. 6 also shows an example of an exposure apparatus used in combination with the substrate processing apparatus. FIG. 7 shows an example of the internal configuration of the substrate processing apparatus 20 shown in FIG. 6. The substrate processing apparatus 20 shown in FIGS. 6 and 7 includes a carrier block 24, a processing block 25, and an interface block 26. The workpiece W is processed by the substrate processing apparatus 20 using the above-described method.

[0069] The carrier block 24 is a block configured to introduce the workpiece W into the substrate processing apparatus 20 and to remove the workpiece W from the substrate processing apparatus 20. The carrier block 24 has a transport device A1 including a delivery arm. The transport device A1 removes the workpiece W accommodated in the carrier C and delivers it to the processing block 25, and receives the workpiece W from the processing block 25 and returns it to the carrier C.

[0070] The processing block 25 has processing modules 11, 12, 13, and 14, which are stacked in this order. Each of the processing modules 11, 12, 13, and 14 incorporates a plurality of processing units U1 and U2, and a transport device A3 that transports the workpieces W to these processing units.

[0071] The processing module 11 may be configured to form an underlayer film (a film to be etched) on the surface of a substrate (e.g., a semiconductor wafer) as the workpiece W. In the processing module 11, for example, the processing unit U1 may be a liquid processing unit that applies a coating liquid for forming the underlayer film to the workpiece W, and the processing unit U2 may be a heat processing unit that heat-treats the applied coating liquid to form the underlayer film.

[0072] The processing module 12 may be configured to form a resist film on an underlying film (film to be etched) of the workpiece W. In the processing module 12, for example, the processing unit U1 may be a coating unit that applies a photoresist composition to the workpiece W, and the processing unit U2 may be a heat treatment unit that bakes the applied photoresist composition to form a resist film. The workpiece W having the resist film may be transported to the exposure device 30 via the interface block 26, where a first radiation may be irradiated onto a portion of the resist film.

[0073] The processing module 13 may be configured to bake the resist film having a portion irradiated with the first radiation in the exposure apparatus 30, and then irradiate the resist film with the second radiation. In the processing module 13, for example, the processing unit U1 may be a thermal processing unit for baking the resist film before it is irradiated with the second radiation, and the processing unit U2 may be an exposure unit having a light source of the second radiation.

[0074] The processing module 14 may be configured to function as a developing unit that removes a portion of the resist film irradiated with the second radiation by contacting it with a developer, thereby forming a resist pattern. In the processing module 14, for example, the processing unit U1 may be a liquid processing unit that supplies a developer and, if necessary, a rinse liquid to the resist film, and the processing unit U2 may be a heat processing unit that heat-treats the resist film before development.

[0075] The processing block 25 further has a shelf unit U10 provided on the carrier block 24 side. The shelf unit U10 is divided into multiple cells lined up in the vertical direction. A transport device A7 including a lifting arm is provided near the shelf unit U10. The transport device A7 raises and lowers the workpiece W between the cells of the shelf unit U10. The processing block 25 has a shelf unit U11 provided on the interface block 26 side. The shelf unit U11 is divided into multiple cells lined up in the vertical direction.

[0076] The interface block 26 is configured to transfer the workpiece W between the processing block 25 and the exposure device 30. The interface block 26 has a built-in transport device A8 (transport unit) that includes a transfer arm. The transport device A8 transfers the workpiece W placed on the shelf unit U11 to the exposure device 30. The transport device A8 receives the workpiece W from the exposure device 30 and returns it to the shelf unit U11.

[0077] The control device 100 (control unit) controls the units constituting each block so that a desired resist pattern is formed on the workpiece W. For example, the control device 100 controls an exposure unit (e.g., a processing unit U1 in a processing module) so that the second radiation is irradiated collectively onto the entire area of ​​the resist film, including the portion irradiated with the first radiation and the other portion. The control device 100 can also control a transport unit (transport device A8) in the interface block 26 so that the workpiece having the resist film irradiated with the first radiation in the exposure device 30 is transported to the exposure unit.

[0078] The control device 100 may have a storage that stores a program for causing the units constituting each block to execute the above-described method. The storage includes, for example, a computer-readable storage medium that stores the program and a device that reads data from the storage medium. The storage medium is a non-transitory medium, examples of which include a hard disk and a read-only memory (ROM).

[0079] The specific configuration of the substrate processing apparatus is not limited to the above-described configuration of the substrate processing apparatus 20. For example, an exposure unit that irradiates the resist film having a portion irradiated with the first radiation with the second radiation may be provided between the processing block and the interface block. [Example]

[0080] The present invention is not limited to the following verification examples.

[0081] Verification example 1 1-1. Photoresist composition As a resist material, nanoparticles containing cage-shaped tin oxide compounds and organic ligands ([(SnR) 12 O 14

[0043] ((OH)6) (OH)2, where R is an alkyl group, hereinafter sometimes referred to as "MOR") was prepared. A 0.01 M MOR solution was prepared as photoresist composition 1.

[0082] 1-2.Pattern formation test Comparative Example 1 Photoresist composition 1 was applied to a silicon oxide film formed on a silicon wafer using a spin coater. The coating was heated at 100°C for 60 seconds to remove the solvent, forming a resist film with a thickness of 22 nm. The resist film was exposed to extreme ultraviolet (EUV) radiation with a wavelength of 13.5 nm through a mask having a pattern corresponding to a line / space pattern with a half pitch of 32 nm. The EUV radiation dose was 69.5 J / cm. 2 After exposure, the resist film was baked at 180°C for 60 seconds. The baked resist film was developed using PGMEA (propylene glycol monomethyl ether acetate) containing acetic acid. After development, the line width (CD) and line edge roughness (LER) of the resist pattern were measured by observing the formed linear resist pattern with a scanning electron microscope.

[0083] Example 1-1 Photoresist composition 1 was applied to an SOC film formed on a silicon wafer using a spin coater. The coating was heated at 100°C for 60 seconds to remove the solvent, forming a resist film with a thickness of 22 nm. The resist film was exposed to extreme ultraviolet (EUV) rays with a wavelength of 13.5 nm through a mask having a pattern corresponding to a line / space with a half pitch of 32 nm. After exposure, the resist film was baked by heating at 180°C for 60 seconds. The entire surface of the baked resist film was exposed to a KrF excimer laser. The EUV dose was 65.5 J / cm. 2 The dose of the KrF excimer laser is 10 mJ / cm 2The resist film after exposure to the KrF excimer laser was developed using PGMEA (propylene glycol monomethyl ether acetate) containing acetic acid. After development, the line width (CD) and line width roughness (LER) of the resist pattern were measured by observing the formed linear resist pattern with a scanning electron microscope.

[0084] Example 1-2 EUV dose of 61.5J / cm 2 and the dose of the KrF excimer laser was changed to 20 mJ / cm 2 A resist pattern was formed in the same manner as in Example 1-1, except for changing the following: The line width (CD) and line edge roughness (LER) of the resist pattern were measured.

[0085] [Table 1]

[0086] The evaluation results shown in Table 1 confirm that the combination of baking after pattern exposure and floodwise exposure after baking reduces the roughness of the resist pattern.

[0087] Verification example 2 2-1. Photoresist composition Photoresist composition 2 was prepared, containing a polymer component that becomes soluble in a developer by the action of acid and a photoacid generator (PAG) that is a sulfonium salt having a cation represented by the following formula: The sulfonium salt having a cation represented by the following formula also functions as a sensitizer precursor component.

[0088] [ka]

[0089] 2-2.Pattern formation test Comparative Example 2 Photoresist composition 2 was applied to an SOC film formed on a silicon wafer using a spin coater. The coating was heated at 130°C for 60 seconds to remove the solvent, forming a resist film with a thickness of 50 nm. The resist film was exposed to a KrF excimer laser through a mask having a pattern containing a 150 nm wide circular opening. The dose of the irradiated KrF excimer laser was 10 to 200 mJ / cm. 2 (45.9J / cm 2 After exposure, the resist film was baked at 110°C for 60 seconds. The baked resist film was developed using an aqueous tetramethylammonium hydroxide solution. After development, the resist pattern was observed using a scanning electron microscope to measure the line width roughness (LWR) of the resist pattern.

[0090] Example 2-1 Photoresist composition 2 was applied to an SOC film formed on a silicon wafer using a spin coater. The coating was heated at 130°C for 60 seconds to remove the solvent, forming a resist film with a thickness of 50 nm. The resist film was exposed to a KrF excimer laser through a mask having a pattern containing a 150 nm wide circular opening. The dose of the irradiated KrF excimer laser was 10 to 200 mJ / cm. 2 (41.4J / cm 2 After exposure, the resist film was baked at 110°C for 60 seconds. The entire surface of the baked resist film was exposed to UV light of 395 nm. The UV dose was 5 J / cm. 2 The resist film after UV exposure was developed with an aqueous solution of tetramethylammonium hydroxide. After development, the formed resist pattern was observed with a scanning electron microscope to measure the line width roughness (LWR) of the resist pattern.

[0091] Example 2-2 KrF excimer laser dose 39.8 mJ / cm 2 and UV dose was changed to 10J / cm 2A resist pattern was formed in the same manner as in Example 2-1, except for changing the following: The line width roughness (LWR) of the resist pattern was measured.

[0092] Example 2-3 KrF excimer laser dose 39.1 mJ / cm 2 and UV dose was changed to 15J / cm 2 A resist pattern was formed in the same manner as in Example 2-1, except for changing the following: The line width roughness (LWR) of the resist pattern was measured.

[0093] [Table 2]

[0094] The evaluation results shown in Table 2 confirm that the combination of baking after pattern exposure and floodwise exposure after baking reduces the roughness of the resist pattern.

[0095] The present disclosure includes at least the following aspects. [1] irradiating a portion of a resist film including a resist material with a first radiation; baking the resist film; irradiating the entire region of the resist film, including the portion irradiated with the first radiation and the other portion, with a second radiation at once; forming a resist pattern by developing the resist film by removing a portion of the resist film; in this order, the first radiation is ionizing radiation or non-ionizing radiation, the second radiation is non-ionizing radiation, and when the first radiation is non-ionizing radiation, the second radiation is non-ionizing radiation having a wavelength longer than that of the first radiation; A method for forming a resist pattern. [2] The method according to [1], wherein the resist material is a metal oxide photoresist material. [3] The method according to [1], wherein the resist material is a chemically amplified photoresist material comprising a polymer component that becomes soluble or insoluble in a developer by the action of an acid, and an acid generator that generates an acid in response to the first radiation, and the resist material further comprises a sensitizer precursor component as one or more components selected from the polymer component, the acid generator, and a component other than these, and the sensitizer precursor component increases absorption of the second radiation by the resist material by the action of an acid. [4] The method according to any one of [1] to [3], wherein the second radiation is ultraviolet light having a wavelength of 100 nm or more and 450 nm or less. [5] The method according to any one of [1] to [4], further comprising irradiating the resist pattern formed by the development with ultraviolet light, baking the resist pattern formed by the development, or both of these. [6] 1. A method for manufacturing a semiconductor device having a patterned film, the method comprising: forming a resist pattern on a film to be etched, the resist pattern having trenches through which the film to be etched is exposed, by the method according to any one of [1] to [5]; etching the film to be etched exposed in the trench, thereby patterning the film to be etched; A method comprising: [7] a heat treatment unit for baking a resist film formed on a workpiece having a film to be etched; an exposure unit that irradiates the resist film having a portion irradiated with the first radiation with a second radiation; a developing unit for forming a resist pattern by developing the resist film by removing a portion of the resist film; a control unit that controls the exposure unit so that the second radiation is irradiated simultaneously onto an entire region of the resist film, including the portion irradiated with the first radiation and other portions; Equipped with the first radiation is ionizing radiation or non-ionizing radiation, the second radiation is non-ionizing radiation, and when the first radiation is non-ionizing radiation, the second radiation is non-ionizing radiation having a wavelength longer than that of the first radiation; Substrate processing equipment. [8] A computer-readable storage medium storing a program for causing an apparatus to execute the method according to any one of [1] to [5]. [Explanation of symbols]

[0096] 1...semiconductor wafer, 3...film to be etched, 3A...patterned film to be etched, 3a, 5a...trench, 5...resist film, 5A...resist pattern, 5E...portion of resist film irradiated with first radiation, 7...mask, R1...first radiation, R2...second radiation, 11, 12, 13, 14...processing module, 20...substrate processing apparatus, 24...carrier block, 25...processing block, 26...interface block, 30...exposure apparatus, 100...control apparatus, C...carrier, W...work, U1, U2...processing unit.

Claims

1. a heat treatment unit for baking a resist film formed on a workpiece having a film to be etched; an exposure unit that irradiates the resist film having a portion irradiated with the first radiation with a second radiation; a developing unit for forming a resist pattern by developing the resist film by removing a portion of the resist film; a control unit that controls the exposure unit so that the second radiation is irradiated simultaneously onto an entire region of the resist film, including the portion irradiated with the first radiation and other portions; Equipped with the first radiation is ionizing radiation or non-ionizing radiation, the second radiation is non-ionizing radiation, and when the first radiation is non-ionizing radiation, the second radiation is non-ionizing radiation having a wavelength longer than that of the first radiation; the resist film comprises a metal oxide photoresist material; Substrate processing equipment.

2. The substrate processing apparatus according to claim 1 , wherein the second radiation is ultraviolet radiation having a wavelength of 100 nm or more and 450 nm or less.

3. The substrate processing apparatus according to claim 1 , wherein the control unit controls the exposure unit to irradiate the resist pattern formed by the development with the second radiation, which is ultraviolet light.

4. The substrate processing apparatus according to claim 1 , wherein the control unit controls the heat processing unit to bake the resist pattern formed by the development.

5. the control unit has a storage; the storage includes a computer-readable storage medium that stores a program, and a device that reads data from the storage medium; The program, baking the resist film formed on the workpiece having the film to be etched in the heat treatment unit; irradiating the entire area of ​​the resist film, including the portion irradiated with the first radiation and other portions, with the second radiation in the exposure unit; forming the resist pattern by the developing unit by removing a portion of the resist film; The substrate processing apparatus according to claim 1 , wherein the program is for causing the substrate processing apparatus to execute a method including the steps of:

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