High energy ray resist composition, method for producing high energy ray resist composition, method for forming resist pattern, and method for producing semiconductor device

Abstract

The objective of the present disclosure is to provide a resist composition which is for a high-energy ray, and can form a resist film having good film quality and adhesion to a substrate when the resist composition is used for lithography using a high-energy ray. The resist composition for a high-energy ray includes an anion represented by general formula (1) and a metal-containing cluster. In general formula (1), R1 represents an organic group having 1 to 30 carbon atoms, and R2 and R3 each independently represent a fluorine atom, a hydrogen atom or an organic group having 1 to 5 carbon atoms.

Description

[Technical field]

[0001] The present invention relates to a resist composition for use with high-energy radiation. More specifically, the present invention relates to a resist composition for use with extreme ultraviolet radiation and / or an electron beam. The present invention also relates to a method for producing a resist composition for use with high-energy radiation, a method for forming a resist pattern, and a method for producing a semiconductor device. [Background technology]

[0002] Lithography using extreme ultraviolet (EUV) or electron beams is a promising method for achieving high productivity and high resolution in the manufacture of semiconductors and other products. There is therefore a demand for the development of highly sensitive and high resolution resist compositions for use in this method. For example, Non-Patent Document 1 describes a tin-oxocage and an OH - EUV lithography using a resist composition for high energy radiation containing a compound containing an acetate anion, a malonate anion, or a tosylate anion is disclosed. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Jarich Haitjema et al., “Extreme ultraviolet patterning of tin-oxo cages”, J.Micro / Nanokith.HEMS MOEMS., 16(3), 033510(2017) Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, various resist compositions for high-energy rays have been reported. However, there has been a demand for improvements in the film quality (clarity of the resist pattern) and substrate adhesion (developer resistance) of the resist film (resist pattern) formed when the resist composition is applied to lithography using high-energy rays. Therefore, an object of the present disclosure is to provide a resist composition for high-energy rays, which is capable of forming a resist film (resist pattern) that has good film quality and substrate adhesion when used in lithography using high-energy rays. [Means for solving the problem]

[0005] The present inventors conducted various investigations to achieve the above object and arrived at the present invention. That is, the composition of the present disclosure is a resist composition for high-energy radiation, which contains an anion represented by the following general formula (1) and a cluster containing a metal.

[0006] [ka]

[0007] In the above general formula (1), R 1 represents an organic group having 1 to 30 carbon atoms, and R 2 , R 3 each independently represents a fluorine atom, a hydrogen atom, or an organic group having 1 to 5 carbon atoms. Effect of the Invention

[0008] According to the high-energy beam resist composition of the present disclosure, it is possible to create a good pattern in which the occurrence of defects is suppressed in high-energy beam lithography. [Brief description of the drawings]

[0009] [Figure 1]This is an SEM image of a pattern formed by electron beam lithography using a resist composition containing tin oxo cluster hydroxide (compound A). The concentration of compound A in the resist composition is 20 mg / ml, the magnification of the SEM image is 10,000 times, the pattern has a size of 200 nm with a pitch of 600 nm, and the output of the high energy beam is 2000 μC / cm2. [Diagram 2] This is an SEM image of a pattern formed by electron beam lithography using a resist composition (high energy beam resist composition (1) of the present disclosure) containing tin oxocluster vinyl trifluoroborate (compound 1). The concentration of compound 1 in the resist composition is 20 mg / ml, the magnification of the SEM image is 10,000 times, the pattern has a size of 200 nm with a pitch of 600 nm, and the output of the high energy beam is 2000 μC / cm2. [Diagram 3] This is an SEM image of a pattern formed by electron beam lithography using a resist composition containing tin oxocluster hydroxide (compound A). The concentration of compound A in the resist composition is 20 mg / ml, the magnification of the SEM image is 2,500 times, the pattern is 200 nm with a pitch of 600 nm, and the output of the high energy beam is 2000 μC / cm2. [Figure 4] This is an SEM image of a pattern formed by electron beam lithography using a resist composition (high-energy beam resist composition (1) of the present disclosure) containing tin oxocluster vinyl trifluoroborate (compound 1). The concentration of compound 1 in the resist composition is 20 mg / ml, the magnification of the SEM image is 2,500 times, the pattern has a size of 200 nm with a pitch of 600 nm, and the output of the high-energy beam is 2000 μC / cm2. [Diagram 5] This is an SEM image of a pattern formed by electron beam lithography using a resist composition (high-energy beam resist composition (1) of the present disclosure) containing tin oxocluster vinyl trifluoroborate (compound 1). The concentration of compound 1 in the resist composition is 20 mg / ml, the magnification of the SEM image is 100,000 times, the pattern is 20 nm with a pitch of 60 nm, and the output of the high-energy beam is 240 μC / cm2. [Figure 6]1 is a 119Sn NMR chart of tin oxocluster vinyl trifluoroborate (compound 1). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present disclosure will be described in detail below. In addition, a combination of two or more of the individual preferred embodiments of the present disclosure described below is also a preferred embodiment of the present disclosure.

[0011] [High-energy radiation resist composition] The resist composition for high-energy radiation of the present disclosure contains a fluorinated borate anion and a cluster containing a metal. Hereinafter, the compound containing the fluorinated borate anion and the cluster containing a metal is also referred to as the "compound of the present disclosure." In the present disclosure, the term "high energy rays" refers to ionizing radiation or non-ionizing radiation with a wavelength of 13.5 nm or less, and examples of such rays include non-ionizing radiation particles (electromagnetic waves) such as X-rays, light rays (non-ionizing radiation) such as EUV with a wavelength of 1 to 13.5 nm (particularly 13.5 nm), and ionizing radiation particles such as electron beams.

[0012] <Fluorinated borate anions of the present disclosure> The high-energy ray resist composition and the compound of the present disclosure contain a fluorinated borate anion (hereinafter also referred to as the "fluorinated borate anion of the present disclosure"). The fluorinated borate anion of the present disclosure may be an anion having at least one BF bond, but is preferably an anion having a structure represented by the following general formula (1).

[0013] [ka]

[0014] In the above general formula (1), R 1 represents an organic group having 1 to 30 carbon atoms, and R 2 , R 3each independently represents a fluorine atom, a hydrogen atom, or an organic group having 1 to 5 carbon atoms. In the above general formula (1), R 1 The organic group represented by the formula (I) is exemplified by an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, a group in which a hydrocarbon group is bonded to a silicon atom, a cyano group, an acyl group, etc., which may have a substituent. The hydrocarbon group bonded to a silicon atom includes an aliphatic hydrocarbon group and an aromatic hydrocarbon group. The aliphatic hydrocarbon group may be saturated or unsaturated, and may be linear or alicyclic. The hydrocarbon group bonded to a silicon atom is preferably an aliphatic hydrocarbon group having 1 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 15 carbon atoms, more preferably a saturated linear aliphatic hydrocarbon group having 1 to 6 carbon atoms, or an aromatic hydrocarbon group having 6 to 12 carbon atoms. R 1 Examples of the substituent that may be possessed by the organic group represented by the formula (I) include an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, a cyano group, an acyl group, an amino group, an alkoxy group, an aryloxy group (also called an aryloxy group), a hydroxyl group, a carboxyl group, a sulfonic acid group, a sulfate ester group, a phosphoric acid group, and a halogen atom. 1 The organic group represented by the formula (I) may have one or more substituents and may have one or more types of substituents.

[0015] Above R 1 The organic group represented by the formula (I) preferably has 1 or more carbon atoms, more preferably 2 or more carbon atoms, and preferably has 30 or less carbon atoms, more preferably 20 or less carbon atoms, and even more preferably has 10 or less carbon atoms. 1 When the organic group represented by the formula (I) has a substituent, the number of carbon atoms including the substituent is preferably within the above range. In the above general formula (1), R 1Examples of the organic group represented by the formula (I) include unsubstituted or substituted alkyl groups such as a methyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-hexyl group, an n-octyl group, an n-decyl group, a cyclopentyl group, a cyclohexyl group, a benzyl group, a p-methoxybenzyl group, and a phenylethyl group; unsubstituted or substituted alkenyl groups such as a vinyl group, an allyl group, a crotyl group, and a cinnamyl group; a phenyl group, a biphenyl group, a naphthyl group, an anthracenyl group, a toluyl group, a p-tert-butylphenyl group, and the like. unsubstituted or substituted aryl groups such as an nyl group, an m-methoxyphenyl group, a p-iodophenyl group, a p-fluorophenyl group, etc.; unsubstituted or substituted heterocyclic groups such as a thienyl group, a thiazolyl group, a isothiazolyl group, a furyl group, an oxazolyl group, an imidazolyl group, a pyridyl group, a pyrimidyl group, a piperidyl group, a morpholyl group, etc.; groups in which a hydrocarbon group is bonded to a silicon atom such as a trimethylsilyl group, a dimethylsilyl group, a monomethylsilyl group, a triphenylsilyl group, a diphenylsilyl group, a monophenylsilyl group, etc.; a cyano group; and acyl groups such as a formyl group. 1 The organic group represented by the formula (I) is preferably an unsubstituted or substituted alkyl group, an unsubstituted or substituted alkenyl group, or an unsubstituted or substituted aryl group.

[0016] In the above general formula (1), R 1 Examples of the substituent that the organic group represented by the formula (I) may have include the above-mentioned R 1 Examples of the organic group represented by the formula R 1 Examples of the substituent that the organic group represented by the formula (I) may have include the above-mentioned R 1In addition to the groups exemplified as the organic group represented by the formula (I), examples thereof include halogen atoms such as iodine, bromine, and fluorine; unsubstituted or substituted alkoxy groups such as methoxy and ethoxy; unsubstituted or substituted aryloxy groups such as phenoxy; unsubstituted amino groups; substituted amino groups such as monomethylamino, dimethylamino, monodiethylamino, and diethylamino; acid group-containing groups such as carboxyl, sulfonic acid, sulfate, phosphoric acid, and salts thereof; and sulfur-containing groups such as thiol and methylsulfanyl. 1 The substituent which the organic group represented by the following formula (I) may have is preferably a halogen atom or an unsubstituted or substituted alkoxy group, more preferably a halogen atom or an unsubstituted alkoxy group.

[0017] In the above general formula (1), R 1 When the organic group represented by the following formula (I) has a substituent, it may have one or two or more substituents, and it may have one type or two or more types.

[0018] R 2 and / or R 3 is an organic group having 1 to 5 carbon atoms, and preferred embodiments thereof are as described above for R 1 Among the examples and preferred forms of the organic group represented by the formula (I), those having 1 to 5 carbon atoms are the same as those represented by the formula (I). 2 and / or R 3 The organic group represented by the formula (I) may have a substituent. Examples of the substituent and preferred forms thereof are as described above in R 1 The examples and preferred forms of the substituents that may be possessed by the organic group represented by the formula (I) are the same as those of the substituents that may be possessed by the organic group represented by the formula (I). 2 and / or R 3 When the organic group represented by the formula (I) has a substituent, the number of carbon atoms including the substituent is preferably in the range of 1 or more and 5 or less.

[0019] R 2 , R 3 At least one of R is preferably a fluorine atom. 2 , R 3It is more preferable that both of the groups are fluorine atoms.

[0020] <Metal-containing clusters of the present disclosure> The resist composition for high energy radiation and the compound of the present disclosure contain a cluster containing a metal (hereinafter also referred to as the "metal cluster of the present disclosure"). The metal cluster of the present disclosure preferably contains a metal sensitive to high energy radiation, and more preferably contains at least one selected from Sn, Hf, Zr, Co, Pt, Pd, and Zn. The metal is preferably contained as a constituent element of the cluster. In the present disclosure, "sensitive to high energy radiation" means that the absorption cross section for one or more types of ionizing radiation or non-ionizing radiation of 13.5 nm or less (particularly EUV of 13.5 nm) is 1.2 times or more that of carbon, preferably 2 times or more, more preferably 4 times or more, and even more preferably 8 times or more. The absorption cross section of carbon is, for example, 3.5×10 when the wavelength is 13.5 nm (92 eV). 5 cm 2 / mol, and 7.7 × 10 when the wavelength is 6.75 nm (183 eV). 4 cm 2 / mol.

[0021] In the present disclosure, a metal-containing cluster (metal cluster) is a metal compound in which a plurality of metal atoms are directly or indirectly linked by a ligand, and may be a cage-type compound. The metal-containing cluster of the present disclosure may contain any ligand, but may contain one or more ligands selected from aqua ligands, hydroxo ligands, oxo ligands, peroxo ligands, thiolato ligands, sulfide ligands, fluoro ligands, chloro ligands, iodo ligands, hydride ligands, cyanato ligands, azide ligands, carboxylato ligands, oxalato ligands, etc. The metal cluster of the present disclosure preferably contains one or two ligands selected from oxo ligands and peroxo ligands, and more preferably, a plurality of metal atoms are indirectly linked by oxo ligands and / or peroxo ligands. For example, when two or more metal atoms are linked via an oxo ligand, the structure includes MOM, MO(-M)-M, etc. (wherein M represents a metal atom). When two metal atoms are linked via a peroxo ligand, the structure includes MOOM (wherein M represents a metal atom). The metal cluster of the present disclosure is preferably a metal oxide cluster. The metal cluster of the present disclosure preferably contains 2 or more metal atoms in one molecule, preferably 30 or less, more preferably 20 or less, and even more preferably 10 or less. When the number is within the above range, sensitivity in lithography using high-energy beams tends to be improved. The metal clusters of the present disclosure are preferably divalent cations. Specific examples of the metal cluster of the present disclosure include tin oxoclusters, tin hydroxoclusters, Hf oxoclusters, Zr oxoclusters, and the like.

[0022] In the metal cluster of the present disclosure, an organic group is preferably bonded to some or all of the metal atoms. The organic group bonded to the metal atom is preferably R 1The organic group bonded to the metal atom is preferably an organic group having 1 to 30 carbon atoms, and the organic group may have one or more substituents. The preferred form of the organic group bonded to the metal atom is, unless otherwise specified, R in the general formula (1) above. 1 As the organic group bonded to the metal atom, an alkyl group, an alkenyl group or an aryl group having 1 to 20 carbon atoms is particularly preferred, an alkyl group having 1 to 20 carbon atoms is more preferred, and an alkyl group having 1 to 10 carbon atoms is even more preferred.

[0023] <Other ingredients> The high-energy radiation resist composition of the present disclosure may contain any optional components in addition to the fluorinated borate anion of the present disclosure and the metal-containing cluster of the present disclosure. The resist composition for high energy radiation of the present disclosure may contain an organic solvent. Examples of the organic solvent include alcohols such as ethanol, isopropanol, and 1-butanol; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-amyl ketone, methyl isoamyl ketone, and 2-heptanone; ethyl acetate, propyl acetate, butyl acetate, methyl lactate, ethyl lactate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl methoxypropionate, methyl ethoxypropionate, ethoxypropionate, ethyl butyl ether ... Examples of the organic solvent include esters such as ethyl propionate and propylene glycol monomethyl ether acetate; aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butylphenyl ether, ethylbenzene, diethylbenzene, isopropylbenzene, amylbenzene, toluene, xylene, and trimethylbenzene; lactones such as γ-butyrolactone; cyclic ethers such as dioxane; amines such as N,N-dimethylacetamide; halogens such as chloroform and methylene chloride; and the like. The organic solvent may be used alone or in combination of two or more kinds. When two or more kinds are combined, the types and ratios are arbitrary.

[0024] <Composition of high energy ray resist composition> The ratio of boron atoms to metals contained in the high-energy ray resist composition of the present disclosure is 1 to 1×10 5 It is preferably 1 to 1000 mol, more preferably 1 to 20 mol. When it is within the above range, the film quality of the resist film tends to be improved. The metal is preferably at least one selected from Sn, Hf, Zr, Co, Pt, Pd, and Zn. The ratio of the fluorinated borate anion of the present disclosure to the metal cluster of the present disclosure contained in the high-energy ray resist composition of the present disclosure is 0.001 to 5 × 10 4 The amount is preferably 0.01 to 100 mol, more preferably 0.1 to 10 mol. When the amount is within the above range, the film quality of the resist film tends to be improved.

[0025] The resist composition for high energy radiation of the present disclosure preferably contains 1 ppm or more of boron atoms, more preferably 10 ppm or more, and even more preferably 100 ppm or more. When the content is within the above range, the film quality of the resist film tends to improve. In the present invention, unless otherwise specified, "ppm" means a value calculated by mass conversion (for example, 10,000 ppm corresponds to 1 mass%).

[0026] The resist composition for high energy radiation of the present disclosure preferably contains 1 ppm or more of metal, more preferably 10 ppm or more, and even more preferably 100 ppm or more. The content of metal in the resist composition for high energy radiation of the present disclosure is preferably 60 mass% or less, more preferably 50 mass% or less, and even more preferably 40 mass% or less. When the content is within the above range, the film quality of the resist film tends to be improved. The metal is preferably at least one selected from Sn, Hf, Zr, Co, Pt, Pd, and Zn. The content of boron atoms and the content of metal can usually be analyzed by, for example, ICP, ICP-AES, or ICP-MS.

[0027] The content of the organic solvent in the resist composition for high energy radiation of the present disclosure is not particularly limited, and may be appropriately set according to, for example, the coating film thickness, etc., but is preferably 50% by mass or more, more preferably 80% by mass or more, and even more preferably 100% by mass or more, based on 100% by mass of the total solid content of the resist composition for high energy radiation of the present disclosure. In addition, it is preferably 1000% by mass or less, more preferably 800% by mass or less, and even more preferably 500% by mass or less, based on 100% by mass of the total solid content of the resist composition for high energy radiation of the present disclosure. When it is within the above range, the film quality of the resist film tends to be improved. The total solid content of the resist composition for high energy radiation refers to the amount obtained by excluding the content of the solvent from the total amount of the resist composition for high energy radiation. The total solid content can be measured by a known analytical means such as liquid chromatography or gas chromatography.

[0028] [Method of producing a resist composition for use with high-energy rays according to the present disclosure] The high-energy ray resist composition or compound of the present disclosure is preferably produced by including a step of mixing a metal-containing cluster with a fluorinated borate salt (hereinafter also referred to as a "mixing step").

[0029] In the mixing step, it is preferable to perform salt exchange between the anion contained in the metal-containing cluster and the fluorinated borate anion contained in the salt of the fluorinated borate. It is particularly preferable to react the anion represented by the formula (1) with the metal-containing cluster. In the mixing step, a solvent can be used. The type and amount of the solvent may be appropriately selected.

[0030] The method for producing the high-energy radiation resist composition or the compound of the present disclosure preferably includes a purification step, for example, a step of distilling off the solvent after the mixing step and washing with water or an organic solvent.

[0031] The method for producing the high-energy radiation resist composition or the compound of the present disclosure preferably includes a solvent addition step. For example, it is preferable to add a solvent to the high-energy radiation resist composition or the compound of the present disclosure after the purification step to dissolve or disperse the composition.

[0032] The cluster containing a metal used in the production of the high-energy radiation resist composition or the compound of the present disclosure may be produced by a known method. For example, in the case of a metal oxo cluster, R A -M A (=O)-OH (where R A represents an organic group, M A It is preferable to prepare the compound represented by the formula (I) in the presence of an acid catalyst. A is preferably a metal sensitive to high energy rays, and R A A preferred embodiment of the formula is R 1 It is the same as M A is more preferably one selected from Sn, Hf, Zr, Co, Pt, Pd, and Zn, and R A As the alkyl group, an alkenyl group or an aryl group having 1 to 20 carbon atoms is more preferable, an alkyl group having 1 to 20 carbon atoms is even more preferable, and an alkyl group having 1 to 10 carbon atoms is even more preferable. The acid catalyst may be either an organic acid or an inorganic acid. For example, inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, etc.; paratoluenesulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, etc. may be used. The fluorinated borate salt used in the production of the high-energy radiation resist composition or the compound of the present disclosure may be produced by a known method, but a method of synthesis from boronic acid is simple and preferable. It can be easily synthesized from any boronic acid according to the synthesis method described by Vedejs, E.; Chapman, RW; Fields, SC; Lin, S.; Schrimpf, MR et al. in J. Org. Chem. 1995, 60, 3020.

[0033] [Method of forming resist pattern] The pattern formation method of the present disclosure includes a step (i) of applying a high-energy ray resist composition of the present disclosure, a step (ii) of drying the coating film of the high-energy ray resist composition, a step (iii) of exposing the coating film of the high-energy ray resist composition to high-energy rays, and a step (iv) of developing the film of the high-energy ray resist composition.

[0034] <Process (i)> The method for forming a resist pattern according to the present disclosure includes a step (step (i)) of applying the resist composition for high-energy radiation according to the present disclosure. By applying the resist composition for high-energy radiation according to the present disclosure, a coating film of the resist composition for high-energy radiation according to the present disclosure is formed. In the pattern forming method of the present disclosure, the method for applying the high-energy ray resist composition of the present disclosure is not particularly limited, and a resist film can be formed using any application method such as an inkjet method, a spray method, a spin coating method, a dip coating method, or a roll coating method. From the viewpoint of forming a uniform thin film, the spin coating method is preferred.

[0035] The resist composition for high energy radiation of the present disclosure is applied to, for example, a substrate, and the substrate is not particularly limited, and the dimensions and size are arbitrary. Examples of the material include silicon, SiC, nitride semiconductor, GaAs, and AlGaAs. The substrate on which the resist film is formed may have a thin film that is processed into a desired pattern by dry etching or the like, and examples of the thin film include a polysilicon thin film, a laminated film of a polysilicon thin film and a metal thin film, a metal thin film, a Si oxide film, a Si nitride film, a Si oxynitride film, and other insulating thin films. An organic film may be further formed on the thin film. The resist composition for high energy radiation of the present disclosure may be used to form an upper resist film in a multi-layer resist structure.

[0036] The amount of the resist composition for high-energy radiation of the present disclosure applied in step (i) can be appropriately adjusted, for example, so that the resist film has a thickness described below.

[0037] <Process (ii)> The method of forming a resist pattern according to the present disclosure includes a step (step (ii)) of drying the coating film of the high-energy ray resist composition. By drying the coating film of the high-energy ray resist composition, a coating film of the high-energy ray resist composition with a reduced solvent content is formed. Step (ii) is usually carried out after step (i). In the pattern forming method of the present disclosure, the method of drying the coating film of the high energy ray resist composition of the present disclosure is not particularly limited. For example, it is preferable to remove the organic solvent remaining in the resist film by heating the coating film. The heating temperature is preferably 70°C or higher, more preferably 80°C or higher, even more preferably 90°C or higher, preferably 300°C or lower, more preferably 250°C or lower, and even more preferably 200°C or lower. Heating may be performed under two or more different conditions. The heating time is preferably 10 seconds or more, more preferably 20 seconds or more, even more preferably 30 seconds or more, preferably 300 seconds or lower, more preferably 200 seconds or lower, and even more preferably 150 seconds or lower. When step (ii) is performed within the above range, the productivity of the resist film, the film quality of the resist film, and the substrate adhesion tend to be improved. Step (ii) may be carried out under reduced pressure, normal pressure, or elevated pressure, or may be carried out in an inert atmosphere. In step (ii), the coating film after drying (resist film after drying) is preferably dried so that the amount of remaining solvent is as small as possible. For example, the coating film after drying is preferably dried so that the solvent content is 1000 ppm or less.

[0038] <Step (iii)> The method for forming a resist pattern of the present disclosure includes a step (step (iii)) of exposing a coating film of the resist composition for high-energy radiation to high-energy radiation. By exposing the coating film of the resist composition for high-energy radiation to high-energy radiation, a coating film is formed in which the exposed and unexposed parts are cured. Step (iii) is usually carried out after step (ii). In the pattern forming method of the present disclosure, the method of exposing the coating film of the high-energy ray resist composition of the present disclosure to high-energy rays is not particularly limited, but is preferably performed using a high-energy light source through a desired mask pattern. The preferred form of the high-energy rays is as described above.

[0039] Examples of exposure sources used for exposure include an EUV exposure source (LPP) that extracts EUV light from plasma generated by irradiating a target such as tin or its compounds, xenon, etc. with laser light, an EUV exposure source (DPP) that extracts EUV light from plasma generated by high-voltage discharge in the presence of tin or its compounds, or xenon in the vicinity of an electrode made of tungsten, silicon carbide, etc., an EUV exposure source that extracts EUV light from plasma generated by irradiating a target with laser light and causing discharge, an EUV exposure source that extracts EUV light from a synchrotron radiation source, an electron beam irradiation source, etc. A high-energy beam may be extracted from a high-energy light source using a reflective or transmissive filter.

[0040] In the above step (iii), the output of the high energy beam is 0.5 mJ / cm for non-ionizing radiation such as X-rays or EUV light. 2 It is preferable to carry out the treatment at a dose of 1 mJ / cm or more. 2 More preferably, it should be 2 mJ / cm or higher. 2 More preferably, the dose is 500 mJ / cm or more. 2 It is preferable to carry out the treatment at less than 200 mJ / cm 2 It is more preferable to perform it at less than 100 mJ / cm 2 It is more preferable to carry out the treatment at a temperature of 10 μC / cm or less for ionizing radiation particles such as electron beams. 2 It is preferable to carry out the treatment at a temperature of 20 μC / cm or higher. 2 More preferably, it should be performed at 50 μC / cm or higher. 2 More preferably, the temperature is 10,000 μC / cm or higher. 2 It is preferable to carry out the treatment at a temperature of 5000 μC / cm or less. 2 It is more preferable to carry out the test at a temperature of 2500 μC / cm 2It is more preferable to carry out the process within the following range: When step (iii) is carried out within the above range, the productivity of the resist film, and the film quality and substrate adhesion of the resist film tend to be improved.

[0041] <Process (iv)> The method for forming a resist pattern of the present disclosure includes a step (step (iv)) of developing a film of the resist composition for high-energy radiation of the present disclosure. A resist pattern can be formed by the development treatment. Step (iv) is usually carried out after step (iii).

[0042] In the pattern forming method of the present disclosure, the development of the film (resist film) of the resist composition for high energy radiation of the present disclosure can be carried out using any of water, alkaline water, organic solvents, and mixtures thereof. Examples of solvents that can be used as developers include the above-mentioned organic solvents. Examples of suitable organic solvents include alcohols such as 4-methyl-2-pentanol, 1-butanol, isopropanol, 1-propanol, and methanol; esters such as ethyl lactate; ethers such as tetrahydrofuran, dioxane, and anisole; amines such as tetramethylammonium hydroxide; and the like.

[0043] The developer may optionally contain viscosity modifiers, solubilizing aids, surfactants, and the like, as desired.

[0044] The developing time is preferably 10 seconds or more, more preferably 20 seconds or more, and even more preferably 30 seconds or more, and is preferably 300 seconds or less, more preferably 200 seconds or less, and even more preferably 100 seconds or less. When step (iv) is performed within the above range, the productivity of the resist film, the film quality of the resist film, and the substrate adhesion tend to be improved. The developing method is not particularly limited, and examples thereof include a dipping method, a paddle method, a spray method, and the like.

[0045] In the method for forming a resist pattern of the present disclosure, the thickness of the resist film after development is preferably 10 nm or more, more preferably 20 nm or more, even more preferably 30 nm or more, and preferably 100 nm or less, more preferably 80 nm or less, and even more preferably 60 nm or less. The thickness may be determined according to the minimum processing dimension of the desired pattern. If it is within the above range, the film quality of the resist film and the dimensional stability of the resist pattern tend to be improved.

[0046] <Other processes> The pattern forming method of the present disclosure may include any step other than the above steps (i), (ii), (iii), and (iv), such as a step (v) of baking the resist film after exposure to high-energy radiation.

[0047] The above step (v) is optional, but is usually performed after step (iii). As for the baking conditions, the heating temperature is preferably 70°C or higher, more preferably 90°C or higher, even more preferably 110°C or higher, preferably 300°C or lower, more preferably 250°C or lower, and even more preferably 200°C or lower. Heating may be performed under two or more different conditions. The heating time is preferably 10 seconds or more, more preferably 30 seconds or more, even more preferably 60 seconds or more, preferably 300 seconds or lower, more preferably 150 seconds or lower, and even more preferably 120 seconds or lower. When step (v) is performed within the above range, the productivity of the resist film, the film quality of the resist film, and the substrate adhesion tend to be improved.

[0048] From the viewpoint of miniaturization of semiconductor devices, the line width of the resist pattern is, for example, preferably 500 nm or less, more preferably 400 nm or less, and even more preferably 300 nm or less. According to the resist composition for high-energy beams of the present disclosure, a resist film having excellent film quality (pattern clarity) and substrate adhesion (developer resistance) can be formed. Therefore, even in a pattern with a narrow line width such as the above, it is possible to create a good pattern in which the occurrence of defects is suppressed and residual film in unnecessary portions is also suppressed.

[0049] [Method of manufacturing semiconductor device] The method for manufacturing a semiconductor device of the present disclosure includes a step (i-b) of applying the high-energy ray resist composition of the present disclosure onto a substrate, a step (ii-b) of drying the coating of the high-energy ray resist composition to form a resist film, a step (iii-b) of exposing the coating of the high-energy ray resist composition to high-energy rays, and a step (iv-b) of developing the coating of the high-energy ray resist composition. Unless otherwise specified, the form and preferred form of the step (i-b), step (ii-b), step (iii-b), and step (iv-b) are the same as the form and preferred form of the above step (i), step (ii), step (iii), and step (iv), respectively. The method for manufacturing a semiconductor device of the present disclosure may include any step other than the above steps. Examples of the optional step include the steps exemplified in the pattern forming method of the present disclosure.

[0050] [Uses of the high-energy radiation resist composition of the present disclosure] The resist composition for high-energy radiation of the present disclosure can be used in the manufacture of semiconductor devices, masks for semiconductor manufacturing equipment, and the like.

[0051] A resist film (resist pattern) formed using the resist composition for high-energy radiation of the present disclosure has good substrate adhesion (developer resistance). Specifically, it is preferable that the resist film does not peel off upon development. Furthermore, the resist film (resist pattern) formed using the resist composition for high-energy radiation of the present disclosure has good film quality. Specifically, it is preferable that the resist pattern is clear without any joining or disappearance.

[0052] This application claims the benefit of priority based on Japanese Patent Application No. 2021-059689, filed on March 31, 2021. The entire contents of the specification of Japanese Patent Application No. 2021-059689, filed on March 31, 2021, are incorporated by reference into this application. EXAMPLES

[0053] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In addition, unless otherwise specified, "parts" means "parts by mass" and "%" means "% by mass".

[0054] <Synthesis Example 1> In a 1L four-neck flask, 20g (95.8mmol) of monobutyltin oxide and 5.8g (30.3mmol) of paratoluenesulfonic acid monohydrate were added, and 500mL of toluene was further added. Under a nitrogen atmosphere, the mixture was heated and refluxed for 48 hours while removing water generated in the reaction system using a Dean-Stark apparatus. The mixture was then cooled to room temperature, and the unreacted solid was filtered off, and the solution was dried under reduced pressure. 1,4-dioxane was added to the obtained solid, which was recrystallized and purified, and then filtered to obtain 14g of the target tin oxocluster paratoluenesulfonate.

[0055] [ka]

[0056] <Synthesis Example 2> In a 200 mL eggplant flask, 11.4 g of the tin oxocluster paratoluenesulfonate obtained in Synthesis Example 1 was added, and 58 mL of isopropyl alcohol was added to dissolve it. While heating and stirring at 40°C, a solution of 5.5 g of 15 mass% tetramethylammonium hydroxide aqueous solution, 5.7 mL of isopropyl alcohol, and 4 mL of water was slowly added dropwise. After the addition was completed, the mixture was stirred for 10 minutes and then cooled to room temperature. The mixture was left to stand at room temperature for one day, and the resulting solid was filtered and washed with acetonitrile to obtain 4.5 g of the target tin oxocluster hydroxide (compound A).

[0057] [ka]

[0058] <Synthesis Example 3> In a 100 mL recovery flask, 400 mg of the tin oxocluster hydroxide (compound A) obtained in Synthesis Example 2 and 53.6 mg of potassium vinyltrifluoroborate were added, and 10 mL of tetrahydrofuran was added thereto, followed by stirring at room temperature for 30 minutes. Thereafter, the solvent was distilled off, and the resulting solid was washed with water and acetonitrile and dried to obtain 320 mg of tin oxocluster vinyl trifluoroborate (compound 1). 119 When the Sn NMR was confirmed, the spectrum shown in Figure 6 was obtained. 119 Sn NMR: δ=-282.77ppm,-460.97ppm.

[0059] [ka]

[0060] <Synthesis Example 4> In a 100mL eggplant flask, 400mg of tin oxocluster hydroxide (compound A) and 65.6mg of potassium normal butyl trifluoroborate were added, 10mL of tetrahydrofuran was added, and the mixture was stirred at room temperature for 30 minutes. After that, the solvent was distilled off, and the obtained solid was washed with water and acetonitrile, and dried to obtain 330mg of tin oxocluster normal butyl trifluoroborate (compound 2). 119 Sn NMR: δ=-282.99ppm,-460.63ppm.

[0061] <Synthesis Example 5> In a 100mL eggplant flask, 400mg of tin oxocluster hydroxide (compound A) and 82.8mg of potassium (4-fluorophenyl) trifluoroborate were added, 10mL of tetrahydrofuran was added, and the mixture was stirred at room temperature for 30 minutes. After that, the solvent was distilled off, and the obtained solid was washed with water and acetonitrile, and dried to obtain 350mg of tin oxocluster (4-fluorophenyl) trifluoroborate (compound 3). 119 Sn NMR: δ=-282.56ppm,-460.42ppm.

[0062] <Synthesis Example 6> In a 100mL eggplant flask, 400mg of tin oxocluster hydroxide (compound A) and 85.6mg of potassium (3-methoxyphenyl) trifluoroborate were added, 10mL of tetrahydrofuran was added, and the mixture was stirred at room temperature for 30 minutes. After that, the solvent was distilled off, and the obtained solid was washed with water and acetonitrile, and dried to obtain 345mg of tin oxocluster (3-methoxyphenyl) trifluoroborate (compound 4). 119 Sn NMR: δ=-283.54ppm,-461.06ppm.

[0063] <Synthesis Example 7> In a 100 mL eggplant flask, 400 mg of tin oxocluster hydroxide (compound A) and 60.7 mg of potassium allyl trifluoroborate were added, 10 mL of tetrahydrofuran was added, and the mixture was stirred for 1 hour at 70° C. After that, the mixture was cooled to room temperature, and the solvent was distilled off. The obtained solid was washed with water and acetonitrile, and dried to obtain 250 mg of tin oxocluster allyl trifluoroborate (compound 5). 119 Sn NMR: δ=-282.56ppm,-461.02ppm.

[0064] <Synthesis Example 8> In a 100 mL eggplant flask, 400 mg of tin oxocluster hydroxide (compound A) and 127.0 mg of potassium (4-iodophenyl) trifluoroborate were added, and 10 mL of tetrahydrofuran was added thereto and stirred at 70° C. for 1 hour. After that, after cooling to room temperature, the solvent was distilled off, and the obtained solid was washed with water and acetonitrile and dried to obtain 390 mg of tin oxocluster (4-iodophenyl) trifluoroborate (compound 6).

[0065] <Synthesis Example 9> In a 100mL eggplant flask, 400mg of tin oxocluster hydroxide (compound A) and 98.4mg of potassium (4-t-butylphenyl) trifluoroborate were added, 10mL of tetrahydrofuran was added, and the mixture was stirred at room temperature for 30 minutes. After that, the solvent was distilled off, and the obtained solid was washed with water and acetonitrile and dried to obtain 370mg of tin oxocluster (4-t-butylphenyl) trifluoroborate (compound 7).

[0066] <Synthesis Example 10> In a 100mL recovery flask, 400mg of tin oxocluster hydroxide (compound A) and 98.4mg of potassium (2-naphthalene) trifluoroborate were added, 10mL of tetrahydrofuran was added, and the mixture was stirred for 1 hour at 70°C. After cooling to room temperature, the solvent was distilled off, and the resulting solid was washed with water and acetonitrile and dried to obtain 260mg of tin oxocluster (2-naphthalene) trifluoroborate (compound 8). 119 Sn NMR: δ=-282.77ppm,-461.02ppm.

[0067] <Synthesis Example 11> In a 100 mL eggplant flask, 400 mg of tin oxocluster hydroxide (compound A) and 83.6 mg of potassium cyclohexyl trifluoroborate were added, and 10 mL of tetrahydrofuran was added thereto and stirred at 40° C. for 1 hour. After cooling to room temperature, the solvent was distilled off, and the obtained solid was washed with water and acetonitrile and dried to obtain 340 mg of tin oxocluster cyclohexyl trifluoroborate (compound 9). 119 Sn NMR: δ=-283.07ppm,-461.32ppm.

[0068] <Silicon wafer cleaning and surface treatment> The silicon wafer was cut into a square size of about 1.5 cm and ultrasonically cleaned in isopropanol for 10 minutes. Then, it was boiled in isopropanol for 3 minutes. After that, the silicon wafer was taken out from isopropanol, dried with nitrogen blow, and UV ozone cleaning was performed for 2 minutes. Next, the silicon wafer was placed on a spin coater, 150 μL of hexamethyldisilazane was dropped, and after rotating at 4000 revolutions per minute for 35 seconds, it was baked on a hot plate at 150 °C for 1 minute to complete the surface treatment.

[0069] <Film formation on silicon wafer> As a reference, a 20 mg / mL 1-butanol solution of tin oxo cluster hydroxide (Compound A) was prepared (comparative resist composition). Also, a 20 mg / mL 1-butanol solution of tin oxo cluster vinyltrifluoroborate (Compound 1) was prepared (resist composition for high-energy rays of the present disclosure (1)). The surface-treated silicon wafer was placed on a spin coater, each prepared solution was dropped, and after rotating at 1500 revolutions per minute for 45 seconds, it was baked on a hot plate at 90 °C for 1 minute to complete the surface film formation.

[0070] <EB lithography and subsequent development process> The film-formed silicon wafer was set in an ultra-high-precision electron beam lithography apparatus (manufactured by Elionix: ELS-100T), and lithography was performed while changing the output from 240 μC / cm 2 to 2000 μC / cm 2 After the lithography was completed, the silicon wafer was taken out from the apparatus and baked on a hot plate at 150 °C for 2 minutes. Then, it was immersed in a developer of isopropanol:water = 2:1 for 30 seconds, rinsed with water for 10 seconds, and dried with nitrogen blow.

[0071] <Surface observation> The pattern obtained by lithography was observed on the surface by SEM. Electron beam lithography using a resist composition containing tin oxocluster hydroxide (compound A) (high energy beam output: 2000 μC / cm 2 ) is shown in FIG. 1 at 10,000x magnification, and in FIG. 3 at 2,500x magnification. Electron beam lithography (high energy beam output: 2000 μC / cm ) was performed using a resist composition containing tin oxocluster vinyl trifluoroborate (compound 1). 2 2 shows a SEM image at 10,000 times magnification of the pattern formed by the above method, and FIG. 4 shows a SEM image at 2,500 times magnification of the pattern formed by the above method. In addition, the pattern formed by the above method was also subjected to electron beam lithography (high energy beam output: 240 μC / cm) using a resist composition containing tin oxocluster vinyl trifluoroborate (compound 1). 2 A SEM image at 100,000 times magnification of the pattern formed with ) is shown in FIG.

[0072] <<Substrate adhesion, film quality evaluation>> As a result of observing the surface with an SEM, the pattern having no defects was evaluated as having good adhesion to the substrate, and the pattern having defects was evaluated as having poor adhesion to the substrate. Moreover, a film having a clear pattern without any joining or disappearance of the resist was evaluated as having good film quality. As shown in FIGS. 2, 4 and 5, the resist patterns obtained using the resist composition containing tin oxocluster vinyl trifluoroborate (compound 1) had good substrate adhesion and film quality.

[0073] 1 and 2, and 3 and 4, it can be seen that the resist pattern obtained using a composition containing tin oxocluster vinyl trifluoroborate (compound 1) has fewer defects, better film quality, and higher definition (clearer pattern) than that obtained using tin oxocluster hydroxide (compound A). In addition, as shown in FIG. 5, by using the high-energy ray resist composition (1) of the present disclosure containing tin oxocluster vinyl trifluoroborate (compound 1), it is possible to draw a pattern of about 20 nm, and the pattern can be drawn at a resolution of 240 μC / cm 2At low light levels, the negative and positive types are inverted, and it can be seen that the effect is positive.

[0074] From the above, it has become clear that the high-energy ray resist composition of the present disclosure is capable of producing a clear resist pattern in lithography using high-energy rays, and is capable of forming a resist film with excellent film quality and substrate adhesion.

Claims

1. A resist composition for use with high-energy radiation, comprising an anion represented by the following general formula (1) and a cluster containing a metal, the cluster containing the metal being a tin oxocluster or a tin hydroxocluster: 【Chemistry 1】 In the above general formula (1), R 1 represents an organic group having 1 to 30 carbon atoms, the organic group being an unsubstituted or substituted alkyl group, an unsubstituted or substituted alkenyl group, or an unsubstituted or substituted aryl group; R 2 , R 3 represents a fluorine atom.

2. 2. The resist composition for use with high energy radiation according to claim 1, wherein the metal-containing cluster is a divalent cation.

3. A step (i) of applying the high-energy ray resist composition according to claim 1 or 2; (ii) drying the coating film of the high-energy ray resist composition; (iii) exposing the coating film of the high-energy ray resist composition to high-energy rays; (iv) developing the film of the high-energy ray resist composition; A method for forming a resist pattern comprising the steps of:

4. A step of applying the high-energy ray resist composition according to claim 1 or 2 onto a substrate; drying the coating film of the high-energy ray resist composition; exposing a coating film of the high-energy ray resist composition to high-energy rays; developing the film of the high-energy ray resist composition; A method for manufacturing a semiconductor device comprising the steps of:

5. A method for producing a resist composition for use with high-energy radiation, comprising the step of reacting an anion represented by the following general formula (1) with a cluster containing a metal, wherein the cluster containing a metal is a tin oxocluster or a tin hydroxocluster: 【Chemistry 2】 In the above general formula (1), R 1 represents an organic group having 1 to 30 carbon atoms, the organic group being an unsubstituted or substituted alkyl group, an unsubstituted or substituted alkenyl group, or an unsubstituted or substituted aryl group; R 2 , R 3 represents a fluorine atom.

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