Resist pattern embedding solution and method for manufacturing a resist pattern using the same

Abstract

The present invention provides a resist pattern embedding solution and a method for manufacturing a resist pattern using the same.

Description

[Technical Field]

[0001] This invention relates to a resist pattern embedding solution and a method for manufacturing a resist pattern using the same. [Background technology]

[0002] In recent years, there has been a growing need for higher integration in LSIs, requiring miniaturization of patterns. To meet these needs, lithography processes using short-wavelength light such as KrF excimer lasers, ArF excimer lasers, extreme ultraviolet light, X-rays, and electron beams are being put into practical use. To accommodate this miniaturization of resist patterns, high-resolution photosensitive resin compositions used as resists during microfabrication are also required. While exposure with short-wavelength light can form finer patterns, creating finer structures can sometimes lead to resist pattern collapse.

[0003] Resist pattern collapse can also occur when washing the pattern with pure water after development. To improve resist pattern collapse, there are studies underway to replace the conventional pure water with a rinsing solution for washing. Another method to suppress pattern collapse is to develop the resist film after exposure with a gap-filling composition and remove it by heating (Patent Document 1). Other methods include applying a filling composition to a substrate pattern to form a film and removing it by vaporizing the film (Patent Document 2), applying a coating aqueous solution to a resist pattern to form a coating film on the surface of the resist pattern and then removing it (Patent Document 3), and reversing the resist pattern (Patent Documents 4 and 5). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International release 2017 / 207452 [Patent Document 2] Japanese Patent Publication No. 2022-528609 [Patent Document 3] International release 2018 / 074358 [Patent Document 4] Japanese Patent Publication No. 2022-008804 [Patent Document 5] International release 2015 / 129405 [Overview of the project] [Problems that the invention aims to solve]

[0005] The inventors believed that there was still one or more issues that needed improvement. These included, for example: Many defects occur in fine resist patterns; resist pattern collapse occurs in fine resist patterns; pattern collapse occurs due to surface tension when developer or rinse solution is removed between resist patterns by spin-drying; resist patterns cannot be thoroughly cleaned; precipitation occurs when developer solution is replaced with another material; film peeling occurs during the resist pattern cleaning process; yield is poor. [Means for solving the problem]

[0006] The resist pattern embedding solution according to the present invention forms a resist pattern embedding film. Etching rate of embedded films by dry etching using oxygen-containing etchant (ER F ) but, ER F ≥0.5nm / s and The embedding solution is applied to the resist film after exposure and is different from the developer solution used to form the resist pattern.

[0007] The method for manufacturing a resist pattern according to the present invention comprises the following steps. (1) Apply the above-mentioned resist pattern embedding solution between resist patterns formed on the substrate to form an embedding film; and (2) Remove the embedded film by dry etching using an etchant containing oxygen.

[0008] The method for manufacturing the device according to the present invention comprises the following steps. Forming the resist pattern described above; and (3) Processing using a resist pattern as a mask. [Effects of the Invention]

[0009] By using the resist pattern embedding solution of the present invention, one or more of the following effects can be desired: It can suppress the occurrence of defects in fine resist patterns; it can suppress resist pattern collapse in fine resist patterns; it can clean resist patterns thoroughly; it can suppress film peeling of resist patterns; it does not require heating to remove the embedding film; it can easily remove the embedding film; it is possible to reduce the number of steps required to remove the film from the substrate pattern cleaning process; the embedding film removal process and dry etching of the substrate using the resist pattern as a mask can be performed in one step or consecutively; it can suppress the formation of precipitates due to mixing of the embedding solution and the developer solution; it can increase process efficiency; it is possible to use the original resist pattern as a mask without inverting the resist pattern; it is possible to shorten the time that the developer solution is present between the resist patterns. [Brief explanation of the drawing]

[0010] [Figure 1] This is an explanatory diagram of the resist pattern manufacturing method according to the present invention. [Modes for carrying out the invention]

[0011] The embodiments of the present invention will be described in detail as follows.

[0012] [Definition] In this specification, unless otherwise specified, the definitions and examples set forth in this paragraph shall prevail. The singular form includes the plural form, and "one" or "that" means "at least one." An element of a certain concept can be expressed by multiple types, and when a quantity (e.g., mass %) is given, that quantity represents the sum of those multiple types. "and / or" includes all combinations of elements, as well as their use individually. When a numerical range is indicated using "~" or "-", it includes both endpoints and has the same unit. For example, 5~25 mol% means between 5 mol% and 25 mol%. "C x~y "C x ~C y " and "C x The notation, such as "...", refers to the number of carbon atoms in the molecule or substituent. For example, C 1~6 Alkyl refers to an alkyl chain having between 1 and 6 carbon atoms (such as methyl, ethyl, propyl, butyl, pentyl, and hexyl). When a polymer has multiple types of repeating units, these repeating units copolymerize. These copolymerizations may be alternating copolymerization, random copolymerization, block copolymerization, graft copolymerization, or a mixture of these. When polymers and resins are shown in structural formulas, the n, m, etc., in parentheses indicate the number of repeating units. The unit of temperature used is Celsius. For example, 20 degrees means 20 degrees Celsius. An additive refers to the compound itself that has the function (for example, in the case of a base generator, it is the compound itself that generates a base). The compound may also be added to the composition in the form of being dissolved or dispersed in a solvent. In one embodiment of the present invention, it is preferable that such a solvent is included in the composition according to the present invention as solvent (B) or other component.

[0013] <Resist pattern embedding solution> The resist pattern embedding liquid according to the present invention (hereinafter sometimes referred to as "embedding liquid") is applied to a resist pattern, and forms a resist pattern embedding film (hereinafter sometimes referred to as "embedding film") by, for example, drying a solvent. The embedding liquid according to the present invention can also be referred to as a resist pattern embedding film forming embedding liquid. The embedding liquid according to the present invention is applied to a resist film after exposure and is different from a developer for forming a resist pattern. The embedding liquid according to the present invention is preferably applied to a resist pattern after a developer has been applied, and more preferably, the developer present between resist patterns is replaced and used. At this time, it is more preferable that when the developer and the embedding liquid are mixed, the absorbance does not increase, the turbidity does not increase, or solutes derived from at least any of these do not precipitate. Application of a resist pattern cleaning liquid may or may not be performed between development and application of the embedding liquid. Examples of the resist pattern cleaning liquid include a rinse liquid. It is also possible to replace the developer between resist patterns with a resist pattern cleaning liquid and then replace the cleaning liquid with the embedding liquid according to the present invention.

[0014] When the embedding liquid according to the present invention is applied to a resist pattern, it is preferable that the film thickness of the resist pattern is not substantially changed. The film thickness (FT R ) of the resist pattern or resist film, and applying the embedding liquid directly above any of these, after removing the embedding liquid with the solvent of the embedding liquid, the film thickness (FT R’ ), then Preferably (FT R - FT R’ ) / FT R ×100 = ±0 to 10%. (FT R - FT R’ ) / FT R ×100 is more preferably ±0 to 5%, and even more preferably ±0 to 2%.

[0015] The composition of the embedding solution according to the present invention is not particularly limited, but preferably comprises a polymer (A) and a solvent (B).

[0016] (A) Polymer The embedding solution according to the present invention preferably comprises a polymer (A). More preferably, the solution comprises a polymer (A) selected from the group consisting of vinyl resins, acrylic resins, polystyrene resins, oxazoline resins, polycarbonate resins, novolac resins, epoxy resins, maleic acid resins, and imide resins (even more preferably selected from the group consisting of vinyl resins, acrylic resins, polystyrene resins, oxazoline resins, and polycarbonate resins; even more preferably selected from the group consisting of vinyl resins, acrylic resins, and polystyrene resins). For clarity, polymer (A) may also comprise multiple polymers. For example, polymer (A) may comprise a combination of the aforementioned vinyl resins and polystyrene resins, which is also a preferred embodiment of the present invention.

[0017] In one preferred embodiment, polymer (A) can be synthesized by selecting 1 to 5 types from, for example, the following monomers (more preferably 1 to 3 types; even more preferably 1 to 2 types). [ka]

[0018] The polymer (A) preferably comprises at least one of the repeating units represented by formulas (A-1) and (A-2), and more preferably comprises repeating units represented by formulas (A-1) and (A-2). The polymer (A) may further comprise at least one of the repeating units represented by formulas (A-3) and (A-4). In one preferred embodiment, the polymer (A) comprises repeating units represented by formulas (A-1), (A-2), and (A-3), and more preferably substantially comprises repeating units represented by formulas (A-1), (A-2), and (A-3).

[0019] Equation (A-1) is as follows: [ka] Here, C y 11 Each of these is an aryl or heteroaryl compound, preferably phenyl, having five or six ring atoms independently. R 11 Each of them is independently C 1-5 The alkyl group is preferably methyl or ethyl, and more preferably methyl. In this invention, the expression "methylene in the alkyl group may be replaced by oxy" means that oxy groups may be present between the carbon atoms in the alkyl group, and does not mean that the terminal carbon in the alkyl group becomes oxy, i.e., that it has an alkoxy or hydroxyl group. R 12 , R 13 and R 14 These are, independently, hydrogen and C 1-5 Alkyl, C 1-5 It is an alkoxy or -COOH group, preferably hydrogen or methyl, and more preferably hydrogen. p11 is between 0 and 4, preferably 0 or 1, and more preferably 0. p15 is between 1 and 2, preferably 1, provided that p11 + p15 ≤ 5.

[0020] The following are specific examples of equation (A-1). [ka]

[0021] Equation (A-2) is as follows: [ka] Here, C y 21Each of these is an aryl or heteroaryl compound, preferably phenyl, having five or six ring atoms independently. R 21 Each of them is independently C 1-5 The alkyl group is alkyl (where the methylene group in the alkyl group may be replaced by an oxy group), preferably methyl, ethyl, t-butyl, or t-butoxy, more preferably methyl or ethyl, and more preferably methyl. R 22 , R 23 and R 24 These are, independently, hydrogen and C 1-5 Alkyl, C 1-5 It is an alkoxy or -COOH group, preferably hydrogen or methyl, and more preferably hydrogen. p21 is 0 to 5, preferably 0, 1, 2, 3, 4 or 5, more preferably 0 or 1, and even more preferably 0.

[0022] The following are specific examples of equation (A-2). [ka]

[0023] Equation (A-3) is as follows: [ka] Here, R 32 , R 33 and R 34 These are, independently, hydrogen and C 1-5 Alkyl, C 1-5 It is an alkoxy or -COOH group; preferably hydrogen, methyl, ethyl, t-butyl, methoxy, t-butoxy, or -COOH group; more preferably hydrogen or methyl; even more preferably hydrogen. P 31 is H or C 4-20It is an alkyl group. Here, some or all of the alkyl group may form a ring, some or all of the H groups of the alkyl group may be substituted with halogens, and the methylene group in the alkyl group may be replaced by an oxy or carbonyl (-C(=O-)) group. P 31 The alkyl portion is preferably branched or cyclic. 31 C 4-20 When the H of an alkyl group is substituted with a halogen, it is preferable that the entire H is substituted, and the halogen to be substituted is preferably F or Cl, with F being more preferable. 31 C 4-20 In a preferred embodiment of the present invention, the H of the alkyl group is not substituted with a halogen. 31 Preferably, is H, methyl, isopropyl, t-butyl, cyclopentyl, methylcyclopentyl, ethylcyclopentyl, cyclohexyl, methylcyclohexyl, ethylcyclohexyl, adamantyl, methyladamantyl, or ethyladamantyl (more preferably H, t-butyl, ethylcyclopentyl, ethylcyclohexyl, or ethyladamantyl; even more preferably H, t-butyl, ethylcyclopentyl, or ethyladamantyl; and even more preferably t-butyl).

[0024] The following are specific examples of equation (A-3). [ka]

[0025] Equation (A-4) is as follows: [ka] Here, R 41 Each of them is independently C 1-5 The alkyl group is alkyl (where the methylene group in the alkyl group may be replaced by an oxy group), preferably methyl, ethyl, or t-butyl, and more preferably methyl. R 45 Each of them is independently C 1-5The alkyl group is alkyl (where the methylene group in the alkyl group may be replaced by an oxy group), and is preferably methyl, t-butyl, or -CH(CH3)-O-CH2CH3. R 42 , R 43 and R 44 These are, independently, hydrogen and C 1-5 Alkyl, C 1-5 It is an alkoxy or -COOH group, preferably hydrogen or methyl, and more preferably hydrogen. p41 is 0 to 4, more preferably 0 or 1, and even more preferably 0. p45 is 1-2, more preferably 1. p41 + p45 ≤ 5.

[0026] The following are specific examples of equation (A-4). [ka]

[0027] The number of repeating units n of the repeating units (A-1), (A-2), (A-3), and (A-4) in polymer (A). A-1 , n A-2 , n A-3 and n A-4 The following explains this further. n A-1 / (n A-1 +n A-2 +n A-3 +n A-4 ) is preferably 0-100%, more preferably 50-80%, even more preferably 55-75%, and even more preferably 55-65%. n A-2 / (n A-1 +n A-2 +n A-3 +n A-4 ) is preferably 0-100%, more preferably 0-30%, even more preferably 5-25%, and even more preferably 15-25%. n A-3 / (nA-1 +n A-2 +n A-3 +n A-4 ) is preferably 0 to 50%, more preferably 10 to 40%, still more preferably 15 to 35%, and even more preferably 15 to 25%. n A-3 It is also a preferred embodiment of the present invention that n is 0. n A-4 / (n A-1 +n A-2 +n A-3 +n A-4 ) is preferably 0 to 50%, more preferably 0 to 30%, still more preferably 0 to 10%, and even more preferably 0 to 5%. n A-4 It is also a preferred embodiment of the present invention that n is 0. n A-1 / (n A-1 +n A-2 +n A-3 +n A-4 ) = 40 to 80%, n A-2 / (n A-1 +n A-2 +n A-3 +n A-4 ) = 0 to 40%, n A-3 / (n A-1 +n A-2 +n A-3 +n A-4 ) = 10 to 50%, and n A-4 / (n A-1 +n A-2 +n A-3 +n A-4 ) = 0 to 40% are cited as preferred forms.

[0028] Polymer (A) can also contain additional repeating units other than the repeating units represented by (A-1), (A-2), (A-3) and (A-4). The total number n of all repeating units contained in polymer (A) total is defined as (n A-1 +n A-2 +n A-3 +n A-4 ) / n totalThe ratio is preferably 80-100%, more preferably 90-100%, and even more preferably 95-100%. A preferred form of polymer (A) is also the absence of further repeating units.

[0029] The following are specific examples of polymer (A): [ka]

[0030] The mass-average molecular weight (hereinafter sometimes referred to as Mw) of polymer (A) is preferably 2,000 to 100,000, more preferably 4,000 to 80,000, even more preferably 6,000 to 60,000, and even more preferably 8,000 to 40,000. In this invention, Mw can be measured by gel permeation chromatography (GPC). In this measurement, a GPC column set to 40 degrees Celsius, tetrahydrofuran eluent at a rate of 0.6 mL / min, and monodisperse polystyrene as the standard are preferred.

[0031] The polymer (A) content is preferably 0.05 to 50% by mass (more preferably 0.1 to 10% by mass; even more preferably 0.1 to 5% by mass; and even more preferably 0.2 to 2% by mass) based on the total mass of the embedding liquid. The composition according to the present invention may contain polymers other than polymer (A), but a form that does not contain polymers other than polymer (A) is a preferred form.

[0032] (B) Solvent The embedding solution according to the present invention preferably comprises a solvent (B). Solvent (B) is water, a hydrocarbon solvent, an ether solvent, an ester solvent, an alcohol solvent, a ketone solvent, or any combination thereof. Specific examples of solvents include, for example, water, n-pentane, i-pentane, n-hexane, i-hexane, n-heptane, i-heptane, 2,2,4-trimethylpentane, n-octane, i-octane, cyclohexane, methylcyclohexane, benzene, toluene, xylene, ethylbenzene, trimethylbenzene, methylethylbenzene, n-propylbencene, i-propylbencene, diethylbenzene, i-butylbenzene, triethylbenzene, di-i-propylbencene, n-amylnaphthalene, trimethylbenzene, methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, sec-butanol, t-butanol, n-pentanol, i-pentanol, 2-methylbutanol, sec-pentanol, t-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, heptanol-3, n-octanol, 2-ethylhexanol, sec-octanol, n-nonyl alcohol, 2,6-dimethylheptanol-4, n-decanol, sec-un Decyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec-heptadecyl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, phenylmethylcarbinol, diacetone alcohol, cresol, ethylene glycol, propylene glycol, 1,3-butylene glycol, pentanediol-2,4, 2-methylpentanediol-2,4, hexanediol-2,5, heptanediol-2,4, 2-ethylhexanediol Ru-1,3, diethylene glycol, dipropylene glycol, triethylene glycol, tripylene glycol, glycerin, acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-i-butyl ketone, 2-heptanone, ethyl-n-butyl ketone, methyl-n-hexyl ketone, di-i-butyl ketone, trimethylnonanone, cyclohexanone, cyclopentanone, methylcyclohexanone, 2,4-pentanedione, acetonylacetone, diacetone alcohol, acetophenone,Fencheon, ethyl ether, i-propyl ether, n-butyl ether (di-n-butyl ether, DBE), n-hexyl ether, 2-ethylhexyl ether, ethylene oxide, 1,2-propylene oxide, dioxolane, 4-methyldioxolane, dioxane, dimethyldioxane, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol mono-n-hexyl ether, ethylene glycol monophenyl ether, ethylene glycol mono-2-ethylbutyl ether, ethylene glycol dibutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol di-n-butyl ether, diethylene glycol mono-n-hexyl ether, ethoxytriglycol, tetraethylene glycol di-n-butyl ether, propylene glycol monomethyl ether (PGME), propylene glycol Polypropylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, diethyl carbonate, methyl acetate, ethyl acetate, γ-butyrolactone, γ-valerolactone, n-propyl acetate, i-propyl acetate, n-butyl acetate (n-butyl acetate, nBA), i-butyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methylcyclohexyl acetate, n-nonyl acetate, methyl acetoacetate, ethyl acetoacetate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether,Diethylene glycol acetate mono-n-butyl ether, propylene glycol acetate monomethyl ether, propylene glycol acetate monoethyl ether, propylene glycol acetate monopropyl ether, propylene glycol acetate monobutyl ether, dipropylene glycol acetate monomethyl ether, dipropylene glycol acetate monoethyl ether, glycol diacetate, methoxytriglycol acetate, ethyl propionate, n-butyl propionate, i-amyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate (EL), n-butyl lactate, n-amyl lactate, diethyl malonate Examples include dimethyl phthalate, diethyl phthalate, propylene glycol 1-monomethyl ether 2-acetate (PGMEA), propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, N-methylformamide, N,N-dimethylformamide, N,N-diethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpropionamide, N-methylpyrrolidone, dimethyl sulfide, diethyl sulfide, thiophene, tetrahydrothiophene, dimethyl sulfoxide, sulfolane, and 1,3-propanesultone. These solvents can be used individually or in combination of two or more. Solvent (B) is preferably PGME, PGMEA, EL, nBA, DBE, cyclohexane, 2-heptanone, or a mixture thereof (more preferably PGME, PGMEA, nBA, DBE, or a mixture thereof; even more preferably PGME, PGMEA, or a mixture thereof). Solvent (B) preferably consists of only one or two solvents (more preferably only one). When solvent (B) consists of two solvents, their mass ratio is preferably 5:95 to 95:5 (more preferably 10:90 to 90:10; even more preferably 20:80 to 80:20).

[0033] In relation to other layers or films, one possible form is that solvent (B) does not substantially contain water. For example, the amount of water in the total solvent (B) is preferably 0.1% by mass or less (more preferably 0.01% by mass or less, and even more preferably 0.001% by mass or less). Another preferred form is that solvent (B) does not contain water (0% by mass). Solvent (B) preferably consists substantially of organic solvents (more preferably consisting solely of organic solvents).

[0034] The content of solvent (B) is preferably 60 to 99.9% by mass (more preferably 80 to 99.5% by mass; even more preferably 95 to 99.5% by mass; and even more preferably 97 to 99.5% by mass) based on the total mass of the resist pattern embedding solution.

[0035] (C) Additives The embedding solution according to the present invention may further contain additive (C). Additive (C) is a surfactant, a crosslinking agent, a polymerization initiator, an acid, a basic compound, a surface smoothing agent, a substrate adhesion enhancer, an antifoaming agent, or a combination thereof. An example of an acid is acetic acid. Preferred polymerization initiators include thermal acid generators (TAG), thermal base generators (TBG), or thermal radical generators (more preferably TAG). Additive (C) is preferably a surfactant, a crosslinking agent, a polymerization initiator, or a combination thereof (more preferably a surfactant, an acid, or a combination thereof; even more preferably a surfactant or an acid; even more preferably an acid). Including a polymerization initiator and a crosslinking agent as additive (C) to cure the film by heating is also one embodiment of the present invention. The content of additive (C) (or the sum of multiple additives) is preferably 0 to 10% by mass (more preferably 0 to 8% by mass; even more preferably 0.01 to 5% by mass) based on the total mass of the embedding solution. A composition according to the present invention that does not contain additive (C) (0% by mass) is also an embodiment of the present invention.

[0036] The embedded film of the present invention does not need to exhibit photosensitivity itself, and therefore does not require a photoacid generator (PAG) and a photobase generator (PBG). One of the features of the present invention is that the embedded solution of the present invention does not need to substantially contain PAG(D) and PBG(E). Therefore, the content of PAG(D) and / or PBG(E) is preferably 0.00 to 0.5% by mass (more preferably 0.00 to 0.2% by mass; even more preferably 0.00 to 0.1% by mass; even more preferably 0.00 to 0.01% by mass) based on the total mass of the embedded solution. It is also a preferred embodiment of the present invention that the embedded solution of the present invention does not contain PAG(D) and PBG(E) (0.00% by mass).

[0037] <Method for manufacturing resist patterns> The method for manufacturing a resist pattern according to the present invention comprises the following steps. (1) Applying the embedding solution according to the present invention between resist patterns formed on the substrate to form an embedding film; and (2) Remove the embedded film by dry etching using an etchant containing oxygen.

[0038] Process (1) A resist pattern is formed on a substrate (for example, a silicon / silicon dioxide coated substrate, a silicon nitride substrate, a silicon wafer substrate, a glass substrate, and an ITO substrate, etc.), and the embedding solution according to the present invention is applied between the resist patterns. In the present invention, "above" includes cases where it is formed directly on top of the substrate and cases where it is formed via other layers. For example, a planarization film or an underlayer anti-reflective film may be formed directly on top of the substrate, and the resist composition may be applied directly on top of that. A preferred embodiment of the present invention is to apply the resist composition directly on top of the substrate to form a resist film. The application method is not particularly limited, but examples include coating by a spinner or coater. After application, a filling film is formed by drying or the like.

[0039] The method for forming the resist pattern is not particularly limited. The resist composition is preferably a metal oxide-containing resist composition, more preferably an organometallic oxide hydroxide-containing resist composition, and the one described in Japanese Patent Application Publication No. 2021-73367 can be used. The resist composition is preferably an EUV metal oxide-containing resist composition, and in one preferred embodiment, it is a negative-type resist. The solvent for the metal oxide-containing resist composition is preferably an aromatic solvent (e.g., xylene, toluene), an ether solvent (e.g., anisole, tetrahydrofuran), an ester solvent (e.g., PGMEA, ethyl acetate, nBA, ethyl lactate), an alcohol solvent (e.g., 4-methyl-2-propanol, 1-butanol, methanol, isopropyl alcohol, 1-propanol), a ketone solvent (e.g., methyl ethyl ketone, 2-heptanone), or any combination thereof.

[0040] The resist composition is applied to the substrate and then preferably heated to form a resist film. The heating temperature is preferably 75 to 140°C (more preferably 80 to 130°C; even more preferably 90 to 120°C). The heating time is preferably 30 to 240 seconds (more preferably 90 to 180 seconds). Heating is preferably carried out in an atmosphere of air or nitrogen gas. The thickness of the resist film is preferably 10 to 50 nm (more preferably 15 to 30 nm; even more preferably 15 to 25 nm). The resist film is exposed through a predetermined mask. The wavelength of light used for exposure is not particularly limited, but exposure with light having a wavelength of 13.5 to 248 nm is preferred. Specifically, a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm), and extreme ultraviolet light (wavelength 13.5 nm) can be used, with extreme ultraviolet light being preferred. These wavelengths are allowed within a range of ±1%. After exposure, a Post Exposure Bake (PEB) can be performed if necessary. The PEB temperature is preferably 100-200°C (more preferably 150-190°C), and the heating time is preferably 30-240 seconds (more preferably 90-180 seconds). The exposed resist film is developed using a developer to form a resist pattern. Examples of development methods include alkaline development and organic solvent development, but organic solvent development is preferred. The developer contains an organic solvent, and more preferably an organic solvent. In the case of organic solvent development, examples of developers include hydrocarbon solvents, ether solvents, ester solvents, ketone solvents, and alcohol solvents, with ester solvents or ketone solvents being preferred. Specific examples of developers include 2-heptanone, nBA, and PGMEA. Although not bound by theory, since the embedding solution of the present invention is different from the developer of the resist pattern, the following effects can be expected. There is a method of developing a resist film and forming a resist pattern by using a solvent in the developer that has similar properties to the solvent in the resist composition. In this case, if the developer remains between the resist patterns for a long time, it may dissolve the resist film or resist pattern, reducing the film thickness or the thickness of the pattern walls. By using different solutions for the embedding solution and the developer, the time the developer remains between the resist patterns can be shortened. Furthermore, although not bound by theory, if the developer and the embedding solution are the same, the following phenomena may occur: Since it is desirable for the developer to dissolve the soluble parts of the resist film and then solidify the solid components of the developer after the dissolution has been flushed away, the amount of developer used may increase. Also, the dissolution of the soluble parts of the resist film and the solidification of the solid components of the developer may occur in parallel, and residue from the resist film may enter the film derived from the developer. When selecting a resist pattern with high etch resistance, such residue can act as an undesigned mask. It is believed that these problems can be avoided by using the present invention.

[0041] The embedding solution according to the present invention is applied between resist patterns, preferably to the resist patterns after the developer has been applied, and more preferably to replace the developer present between the resist patterns. Figure 1(i) shows a state in which a resist pattern 1 is formed directly on the substrate 2, and developer solution 3 remains between the resist patterns. In this state, the embedding solution according to the present invention can be applied. After applying the embedding solution, the embedding film is formed by spin-drying or heating, preferably by heating. The heating temperature is preferably 75-140°C (more preferably 80-130°C; even more preferably 90-120°C). The heating time is preferably 30-90 seconds (more preferably 45-75 seconds). Heating is preferably carried out in an atmosphere of air or nitrogen gas. Figure 1(ii) shows the state in which the embedding solution has been replaced with the developer solution and applied, forming the embedding film 4. Figure 1(ii) shows the embedding film completely embedding the resist pattern, but it may also be partially embedded. Even in cases where the embedding film is formed only at the bottom between the resist patterns, it can still provide the effect of preventing pattern collapse. The distance from the substrate surface to the surface of the embedded film is preferably 20-150%, more preferably 40-130%, and even more preferably 60-110% of the distance from the substrate surface to the top of the resist pattern. In Figure 1(ii), the embedded film is embedded so as to completely cover the resist pattern, so the distance is greater than 100%. A preferred embodiment of the present invention is a state in which the embedded film does not completely cover the resist pattern, the top of the resist pattern wall is not covered by the embedded film, and the embedded film is embedded in the trench portion. In this case, the distance from the substrate surface to the surface of the embedded film is preferably 30-80% (more preferably 30-70%; even more preferably 40-60%) of the distance from the substrate surface to the top of the resist pattern. The distance from the substrate surface to the surface of the embedded film is measured in the trenches between the walls of the resist pattern. The midpoint between the walls may be used as the reference point. Similarly, the distance from the substrate surface to the top of the resist pattern is measured by measuring the vertical distance between the trench and the top of the resist pattern wall.

[0042] The embedded membrane according to the present invention preferably satisfies the following formula. (Total number of atoms of the components constituting the embedded film) / ((Number of carbon atoms of the components constituting the embedded film) - (Number of oxygen atoms of the components constituting the embedded film)) = 1.0 to 9.0; more preferably 1.2 to 6.0; even more preferably 1.4 to 4.0. If the solid components forming the embedded film include other components in addition to polymer (A) (for example, a crosslinking agent), these are also included as components of the above formula. This can be calculated using molar ratios. The embedded film according to the present invention preferably has resistance to heating during solvent removal. The glass transition temperature Tg is preferably 100°C or higher, more preferably 100 to 180°C, even more preferably 120 to 160°C, and even more preferably 120 to 150°C. Although not bound by theory, it is thought that having such a Tg can suppress the liquefaction of solid components (e.g., polymer (A)) during heating to remove solvent (B), which would cause the resist pattern to collapse.

[0043] Process (2) The embedded film is removed by dry etching using an oxygen-containing etchant. Alternatively, after removing only the embedded film, processing may be carried out using another etching method (preferably dry etching) to mask the resist pattern. The removal of the embedded film and the processing of the substrate using the resist pattern as a mask can be performed in one or consecutive dry etching steps. Preferably, steps (2) and (3) are performed simultaneously in a single dry etching step. Etching rate of embedded films by dry etching using oxygen-containing etchant (ER F ) ER F The wavelength is preferably ≥0.5 nm / s (more preferably ≥0.8 nm / s). Etching rate of resist patterns by dry etching using oxygen-containing etchant (ER R ) ER R The speed is preferably <0.5 nm / s (more preferably ER R <0.3 nm / s). ERF / ER R Preferably, it is >1.0 (more preferably >2.5). Although not bound by theory, by adopting such an etching rate configuration, the resolution of the resist film itself can be used as the etch mask. This is a major difference from the inverted resist pattern technique. Dry etching can be either anisotropic or isotropic, but anisotropic is preferred. Etching conditions can be, for example, a substrate temperature of 25°C, a pressure of 0.67 Pa, and an input power of 100 W. With respect to oxygen-containing etchants, the oxygen ratio of the etchant in the chamber during plasma generation in dry etching is preferably 10 to 50 volume percent (more preferably 20 to 40 volume percent; even more preferably 25 to 35 volume percent). Figure 1(iii) shows the state after the embedded film 4 has been removed by dry etching.

[0044] <Device manufacturing method> The method for manufacturing the device according to the present invention comprises the following steps. Forming a resist pattern by the method described above; and (3) Processing using a resist pattern as a mask.

[0045] Process (3) The resist pattern is preferably used to process the resist underlayer film or substrate (more preferably the substrate). Specifically, the resist pattern can be used as a mask to process various substrates, such as dry etching, wet etching, ion implantation, and metal plating. Steps (2) and (3) may be the same process or may be performed sequentially. Alternatively, the resist pattern may be used as a mask to form the underlying film pattern, and the underlying film pattern may be used as a mask to process the substrate. Alternatively, the resist pattern may be used as a mask to process the underlying film and the substrate simultaneously. Preferably, the process further includes the step of forming wiring on the processed substrate. These processing methods can be known. Subsequently, if necessary, the substrate is cut into chips, connected to lead frames, and packaged in resin. In this invention, this packaged product is referred to as a device. The device is preferably a semiconductor device.

[0046] The present invention will be described below using various examples. The embodiments of the present invention are not limited to these examples.

[0047] <Preparation of the embedding solution in Example 1> Polymer (A), polymer 1 having the structure shown below, is added to solvent (B) at a concentration of 0.65% by mass. The mixture is stirred at room temperature for 30 minutes, and it is visually confirmed that polymer (A) is dissolved. The mixture is then filtered through a 0.2 μm pore filter to obtain the embedding solution of Example 1. Polymer 1: Mw13,500 [ka]

[0048] <Preparation of embedding solution for Examples 2-6> The embedding solutions of Examples 2 to 6 were obtained in the same manner as the above preparation, except that the components and their contents were changed as shown in Table 1. [Table 1] In the table, • Polymer 2: Mw50,000 [ka] • Polymer 3: Mw18,000 [ka] • Polymer 4: Mw9,800 [ka] • Polymer 5: Mw45,000 [ka]

[0049] <Membrane rippling evaluation> As the resist composition, the resist used in the example of Japanese Patent Publication No. 2020-173360 is used. The same applies hereafter. The resist composition is spin-coated onto a 12-inch silicon wafer that has undergone HMDS treatment, and heated at 100°C for 2 minutes to form a resist film with a thickness of 22 nm. This substrate is exposed to open-frame light without a mask using extreme ultraviolet light with a wavelength of 13.5 nm. This substrate is subjected to PEB in an atmospheric environment at 170°C for 2 minutes. The thickness of the resist film at this time (FT) R The thickness (FT) of the resist film is measured using an M-2000 ellipsometer (JA Woollam). The embedding solutions of Examples 1 to 6 are spin-coated onto the resist film and heated at 130°C for 1 minute to form a film from the embedding solution. Then, the film formed from the embedding solution is removed using 100% of the solvent (B) of the embedding solution. The thickness (FT) of the resist film at this time is measured. R’ ) is measured using an M-2000 ellipsometer. FT R -FT R’ The absolute value of is calculated, and if this absolute value is 2 nm or less, it is classified as A; if it is greater than 2 nm, it is classified as B. The results obtained are listed in Table 1.

[0050] <Preventing pattern collapse: Example> A resist composition is spin-coated onto a 12-inch silicon wafer treated with HMDS, and heated at 100°C for 2 minutes to form a resist film with a thickness of 22 nm. This substrate is exposed to extreme ultraviolet light with a wavelength of 13.5 nm to create a resist pattern with lines of 15 nm and spaces of 15 nm. This substrate is subjected to PEB in an air atmosphere at 170°C for 2 minutes. The resist film on the substrate is paddle-developed with 2-heptanone for 30 seconds. At this point, 2-heptanone remains between the resist patterns. Next, while rotating the substrate at 10 rpm, the embedding solution of the example is poured into the center of the substrate to replace the 2-heptanone. Then, the substrate is rotated at 1500 rpm for 30 seconds and heated at 130°C for 60 seconds to form a embedding film. At this point, the resist pattern is embedded by the solid components of the embedding solution. Next, the substrate is placed in a dry etching apparatus and etched for 30 seconds with a plasma having an oxygen:nitrogen volume ratio of 3:7. The etching conditions were set to a substrate temperature of 25°C, a pressure of 0.67 Pa, and an input power of 100 W. In this case, only the embedded film was removed by dry etching, and the resist pattern was hardly removed. An SEM image (0.5 μm × 0.5 μm) of the resist pattern was taken using a CG4000 (Hitachi High Technology) to check for pattern collapse. If no pattern collapse was observed, the result was classified as A; if pattern collapse was observed, the result was classified as B. The results obtained are shown in Table 1.

[0051] <Pattern collapse prevention: Comparative example> The procedure up to the PEB step is the same as the pattern collapse prevention method described above. After PEB, the resist film on the substrate is paddle-developed with 2-heptanone for 30 seconds. Then, the substrate is rotated at 1500 rpm for 30 seconds to dry. An SEM image of the resulting resist pattern is taken. In this case, a lot of pattern collapse occurs, and it is confirmed to be a B according to the above judgment.

[0052] <Evaluation of chemical solution mixing> The embedding solutions from Examples 1-6 were mixed with 2-heptanone or n-butyl acetate in mass ratios of 1:9, 5:5, and 9:1. The presence or absence of precipitates after mixing was checked using a turbidimeter TR-55 (Kasahara Chemical Industry), and the result was determined according to the following criteria. The results obtained are shown in Table 2. A indicates that no precipitates were found. A: The turbidity is less than 1 degree. B: The turbidity is 1 degree or higher. [Table 2] [Explanation of symbols]

[0053] 1. Resist Pattern 2. Circuit board 3. Developer 4. Embedding membrane

Claims

1. Resist pattern embedding solution: Here, The resist pattern embedding solution forms a resist pattern embedding film. Etching rate (ER) of embedded films by dry etching using an oxygen-containing etchant Ｆ ) but ER Ｆ ≥ 0.5 nm / s, and The embedding solution is applied to the resist film after exposure and is different from the developer that forms the resist pattern: Optionally, the etching rate (ER) of the resist pattern by dry etching using an oxygen-containing etchant. Ｒ ) but ER Ｒ <0.5 nm / s; or Optionally, ER Ｆ / ER Ｒ > It is 1.

0.

2. The embedding solution according to claim 1, which does not substantially alter the film thickness of the resist pattern: Optionally, the thickness of the resist pattern or resist film (FT Ｒ ), and apply the embedding solution directly on either of these, and remove the embedding solution with the solvent of the embedding solution to obtain the film thickness (FT) Ｒ’ If we assume that ), then the following equation will be satisfied: (FT Ｒ -FT Ｒ’ ) / FT Ｒ ×100=±0~10%。

3. The embedding membrane satisfies the following formula, wherein the embedding solution is as described in claim 1 or 2: (Total number of atoms in the components constituting the embedding membrane) / ((Number of carbon atoms in the components constituting the embedding membrane) - (Number of oxygen atoms in the components constituting the embedding membrane)) = 1.0 to 9.

0.

4. The embedding solution according to at least one of claims 1 to 3, wherein the Tg of the embedding membrane is 100°C or higher.

5. An embedding liquid according to at least one of claims 1 to 4, comprising a polymer (A) selected from the group consisting of vinyl resins, acrylic resins, polystyrene resins, oxazoline resins, polycarbonate resins, novolac resins, epoxy resins, maleic acid resins, and imide resins: The mass-average molecular weight (Mw) of polymer (A) is arbitrarily between 2,000 and 100,000.

6. The embedding solution according to at least one of claims 1 to 5, further comprising solvent (B): Here, solvent (B) is water, hydrocarbon solvent, ether solvent, ester solvent, alcohol solvent, ketone solvent, or any combination thereof.

7. The embedding solution according to at least one of claims 1 to 6, further comprising additive (C): Here, additive (C) is a surfactant, crosslinking agent, polymerization initiator, acid, basic compound, surface smoother, substrate adhesion enhancer, defoamer, or any combination thereof.

8. The embedding solution according to at least one of claims 1 to 7, wherein the distance from the surface of the substrate to the surface of the embedding film is 20 to 150% of the distance from the surface of the substrate to the top of the resist pattern.

9. The embedding solution is the embedding solution according to at least one of claims 1 to 8, which is used to replace the developer present between the resist patterns: Optionally, when the developer and embedding solution are mixed, the absorbance does not increase, the turbidity does not increase, or no solute derived from at least one of these does not precipitate; At this point, the application of the resist pattern cleaning solution may or may not be performed between the development and the application of the embedding solution.

10. The embedding solution according to at least one of claims 1 to 9, wherein the oxygen ratio of the etchant in the chamber during plasma generation in dry etching is 10 to 50 volume percent.

11. The embedding solution according to at least one of claims 1 to 10, wherein the resist pattern is formed with a metal oxide-containing resist composition: Optionally, the metal oxide-containing resist composition is an EUV metal oxide-containing resist composition; Optionally, the solvent of the metal oxide-containing resist composition may be an aromatic solvent, an ether solvent, an ester solvent, an alcohol solvent, a ketone solvent, or any combination thereof.

12. The embedding solution according to at least one of claims 1 to 11, wherein the dry etching is anisotropic.

13. The embedding liquid according to at least one of claims 1 to 12, wherein the polymer (A) content is 0.05 to 50% by mass, based on the total mass of the embedding liquid: Optionally, the content of solvent (B) is 60 to 99.9% by mass, based on the total mass of the embedding solution, or The content of additive (C) is optionally 0 to 10% by mass, based on the total mass of the embedding liquid.

14. A method for manufacturing a resist pattern comprising the following steps: (1) Applying the embedding solution according to at least one of claims 1 to 13 between resist patterns formed above the substrate to form an embedding film; and (2) Remove the embedded film by dry etching using an etchant containing oxygen.

15. A method for manufacturing a device comprising the following steps: To form the resist pattern described in claim 14; and (3) Processing using the resist pattern as a mask: Optionally, further comprising the step of forming wiring on a processed substrate; or The device is, arbitrarily, a semiconductor device.

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