Method for producing silicon-containing polymer composition

Abstract

To provide a purification method of a silicon-containing polymer composition capable of reducing metal impurities while suppressing a change of a weight average molecular weight (ΔMW) before and after treatment, by treating the treated silicon-containing polymer composition containing metal impurities with ion-exchange resin having specific structure, a silicon-containing polymer composition, and a producing method of semiconductor devices.SOLUTION: A method for purifying a silicon-containing polymer composition, characterized by treating the treated silicon-containing polymer composition containing organic solvents with a gel-type cation exchange resin, wherein the change in weight average molecular weight (ΔMw) before and after treatment is reduced. The change in weight average molecular weight (ΔMw) before and after the treatment is 70 or less. It is preferable for the ion exchange resin to have strong acidic functional groups. The residual amount of the total of 24 metal elements after the ion exchange treatment is equal to or less than 1 ppb.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an industrially useful method for producing a silicon-containing polymer in which metal impurities that cause defects in the lithography process used in the manufacture of semiconductor devices have been reduced (a method for purifying metal impurities). [Background technology]

[0002] Lithography coating film forming compositions used in lithography processes in the manufacture of semiconductor devices are required to reduce metal impurities that cause microdefects (eg, about 1 to 100 nm, called defects) on wafers.

[0003] A purification method for efficiently obtaining a silicone resin with a low content of alkali metal ions has been disclosed (Patent Document 1).

[0004] In addition, purification by distillation can also be used as a method for efficiently removing metal impurities, but there are problems with this method, such as its inapplicability when the compound to be purified is solid or has a high boiling point, or when the compound to be purified has low thermal stability.

[0005] A method using ion exchange resins is known as a general method for removing metal impurities, but there is a problem in that ion exchange resins act as catalysts that promote the polymerization of alkoxysilanes, accelerating the modification of the compounds to be purified. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2006-342308 A Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made to solve these problems, and has an object to provide a method for producing a silicon-containing polymer composition, which can reduce metal impurities while suppressing the change in weight average molecular weight (ΔMw) before and after treatment by treating a silicon-containing polymer composition containing metal impurities with an ion exchange resin having a specific structure, and a silicon-containing polymer composition.

[0008] As a result of extensive research into achieving the above object, the present inventors have discovered a method for efficiently reducing metal impurities while suppressing denaturation of the silicon-containing polymer (i.e., change in weight average molecular weight (ΔMw)) by treating a silicon-containing polymer composition to be treated that contains metal impurities with a gel-type strongly acidic cation exchange resin having sulfonic acid groups as functional groups, thereby completing the present invention. [Means for solving the problem]

[0009] The present invention encompasses the following:

[0010] [1] A method for producing a silicon-containing polymer composition, characterized in that a silicon-containing polymer composition to be treated containing an organic solvent is treated with a gel-type cation exchange resin, thereby reducing the change in weight average molecular weight (ΔMw) of the silicon-containing polymer before and after the treatment.

[0011] Preferably, the method for producing a silicon-containing polymer composition comprises treating a silicon-containing polymer composition to be treated, which comprises an organic solvent and a silicon-containing polymer, with a gel-type cation exchange resin, and the method reduces the change in weight average molecular weight (ΔMw) of the silicon-containing polymer in the silicon-containing polymer composition after the treatment relative to the silicon-containing polymer in the silicon-containing polymer composition before the treatment.

[0012] [2] The method for producing a silicon-containing polymer composition according to [1], wherein the change in weight average molecular weight (ΔMw) is 70 or less.

[0013] [3] The method for producing a silicon-containing polymer composition according to [1] or [2], wherein the ion exchange resin has a strongly acidic functional group.

[0014] [4] The method for producing a silicon-containing polymer composition according to any one of [1] to [3], wherein the ion exchange resin has a sulfonic acid group as a functional group.

[0015] [5] The method for producing a silicon-containing polymer composition according to any one of [1] to [4], wherein the total amount of the 24 metal elements remaining after the ion exchange treatment is 1 ppb or less.

[0016] Preferably, the method for producing a silicon-containing polymer composition according to any one of [1] to [4], wherein the treated silicon-containing polymer composition further contains metal impurities, and the total amount of Li, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Zr, Mo, Ag, Cd, Sn, Ba, W, and Pb in the silicon-containing polymer composition after the ion exchange treatment is 1 ppb or less.

[0017] [6] The method for producing a silicon-containing polymer composition according to any one of [1] to [5], wherein the treatment is carried out in a batch system or a column flow system.

[0018] [7] The method for producing a silicon-containing polymer composition according to any one of [1] to [6], wherein the weight average molecular weight (Mw) of the treated silicon-containing polymer, i.e., the silicon-containing polymer contained in the treated silicon-containing polymer composition, is 800 to 100,000.

[0019] [8] A silicon-containing polymer composition, in which the change in weight average molecular weight (ΔMw) of the silicon-containing polymer before and after treatment with a gel-type cation exchange resin is 70 or less, and the total amount of 24 metal elements remaining after ion exchange treatment is 1 ppb or less.

[0020] Or a silicon-containing polymer composition having a total content of Li, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Zr, Mo, Ag, Cd, Sn, Ba, W, and Pb of less than 0.8 ppb.

[0021] [9] [8] A silicon-containing resist underlayer film-forming composition comprising the silicon-containing polymer composition according to the present invention.

[0022]

[10] [9] A method for producing a semiconductor device, comprising the steps of: applying the silicon-containing resist underlayer film-forming composition according to claim 1 onto a semiconductor substrate and baking the composition to form a silicon-containing resist underlayer film; applying a resist film-forming composition onto the underlayer film to form a resist film; exposing the resist film; developing the resist film after exposure to obtain a patterned resist film; etching the silicon-containing resist underlayer film with the patterned resist film to pattern it; and processing a semiconductor substrate with the patterned resist film and the silicon-containing resist underlayer film.

[0023]

[11] A method for producing a silicon-containing resist underlayer film-forming composition, comprising a step of treating a silicon-containing polymer composition to be treated, which contains an organic solvent, with a gel-type cation exchange resin, the method reducing a change in weight average molecular weight (ΔMw) of the silicon-containing polymer before and after the treatment.

[0024]

[12]

[11] A method for producing a semiconductor device, comprising the steps of: applying the silicon-containing resist underlayer film-forming composition produced by the method according to claim 1 onto a semiconductor substrate, and baking the composition to form a silicon-containing resist underlayer film; applying a resist film-forming composition onto the underlayer film to form a resist film; exposing the resist film; developing the resist film after exposure to obtain a patterned resist film; etching the silicon-containing resist underlayer film with the patterned resist film to pattern it; and processing a semiconductor substrate with the patterned resist film and the silicon-containing resist underlayer film. Effect of the Invention

[0025] According to the method of the present application, when an ion exchange resin treatment is performed by the method of the present application in the production of a silicon-containing polymer composition that is used in a semiconductor lithography process and that requires high purity, it is possible to reduce metal impurities in the silicon-containing polymer composition while suppressing denaturation of the silicon polymer, specifically, the change in weight average molecular weight (Mw) before and after the treatment (ΔMw).

[0026] According to the method of the present application, it is possible to provide a silicon-containing resist underlayer film-forming composition with reduced metal impurities and a method for producing a semiconductor device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] <Ion exchange resin> An example of an ion exchange resin is one in which ion exchange groups are fixed to the surface of a porous support made of a styrene-divinylbenzene copolymer. Resins are classified as strongly acidic, weakly acidic, etc., depending on the type of fixed exchange group. Strongly acidic resins include sulfonic groups. Weakly acidic resins include carboxyl groups, phosphonic acid groups, phosphinic acid groups, arsenous acid groups, and phenoxide groups. In addition, based on the physical properties of the support, they are classified into gel type, macro-reticular (MR [Micro-Reticular]) type, etc., in which pores are formed in the gel type resin body to make it porous.

[0028] The catalytic action of an ion exchange resin depends on the contact area between the reactant and the ion exchange resin surface and the type of functional group on the ion exchange resin surface. Although not bound by theory, it is assumed that since gel-type ion exchange resins generally only have micropores (pore diameter: 10-10 Å), when the reactant has a large molecular weight such as a polymer, it is difficult for the reactant to penetrate into the resin pores. Since MR-type ion exchange resins have mesopores-macropores (pore diameter: several hundred Å or more), even if the reactant has a large molecular weight such as a polymer, it is possible for the reactant to penetrate into the pores, and it is assumed that the contact area between the polymer and the ion exchange resin surface is relatively large. The ion exchange resin used in the present invention is preferably a gel-type strongly acidic ion exchange resin having a sulfonic acid group.

[0029] As long as it has this characteristic, that is, it is a gel-type cation exchange resin, the ion exchange resin is not particularly limited, and commercially available ion exchange resins can be used.

[0030] The removal of metal impurities with an ion exchange resin can be carried out by treating a solution (treated silicon-containing polymer composition) in which an oily or solid silicon-containing polymer to be treated is redissolved in an organic solvent, or a silicon-containing polymer-containing solution (treated silicon-containing polymer composition) that has been post-treated after synthesis of the silicon-containing polymer to be treated, with an ion exchange resin in a batch or column flow manner.

[0031] The batch method is a method in which the solution to be treated and the ion exchange resin are mixed and stirred for a certain period of time, and then the resin is removed by filtration, etc. The column flow method is a method in which metal impurities are removed from the solution to be treated by passing the solution through a fixed layer such as a column or a packed tower filled with ion exchange resin.

[0032] Comparing the batch system and the column flow system, the column flow system generally enables treatment with the ion exchange resin in a shorter time from the standpoint of contact efficiency between the solution to be treated and the ion exchange resin, and therefore is more effective in reducing the change in weight average molecular weight (ΔMw).

[0033] The number of treatments is usually one, but may be two or more. The treatment time in the batch process varies depending on the type and amount of silicon-containing polymer and ion exchange resin contained in the silicon-containing polymer composition to be treated, and the type and amount of solvent used. Similarly, the liquid passing speed in the column flow process varies depending on the type and amount of silicon-containing polymer and ion exchange resin contained in the silicon-containing polymer composition to be treated, and the type and amount of solvent used. These conditions can be easily optimized by those skilled in the art through routine experiments.

[0034] The amount of ion exchange resin used in the present invention will vary depending on the type of silicon-containing polymer contained in the silicon-containing polymer composition to be treated and the type of organic solvent used, but is usually about 0.01 to 1000 mass % relative to the amount of silicon-containing polymer contained in the silicon-containing polymer composition to be treated, preferably 0.1 to 500 mass %, and more preferably 1 mass % to 100 mass %.

[0035] <Silicon-containing polymer contained in treated silicon-containing polymer composition> The silicon-containing polymer contained in the treated silicon-containing polymer composition used in the present invention is not particularly limited, and may be a commercially available product or a product synthesized by a known method. The silicon-containing polymer can be obtained by polymerizing a commercially available alkoxysilicon compound by a known method (for example, co-condensation by hydrolysis, etc.).

[0036] Specific examples of the alkoxy silicon compound include the following compounds (2-1) to (2-28) manufactured by Shin-Etsu Chemical Co., Ltd.

[0037] [ka] Examples of silicon-containing polymers include those obtained by known methods (e.g., WO2011 / 102470, WO2019 / 003767) and those synthesized according to JP-A-2003-26809.

[0038] Specific examples of the alkoxy silicon compound include the compounds of the following formulas (3-1) to (3-19).

[0039] [ka] [ka]

[0040] <Organic solvent> In the present invention, the organic solvent contained in the treated silicon-containing polymer composition and / or the organic solvent added to the treated silicon-containing polymer composition during the ion exchange treatment may be, for example, the organic solvents described below, but are not limited thereto.

[0041] Examples of the organic solvent include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, propylene glycol propyl ether acetate, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, cycloheptanone, cyclopentyl methyl ether, 4-methyl-2-pentanol, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, and the like. Examples of the solvent include ethyl acetate, 2-hydroxyethyl acetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, 2-heptanone, methoxycyclopentane, anisole, γ-butyrolactone, N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, n-heptane, hexane, isopropyl ether, diisobutyl ether, diisoamyl ether, tert-butyl methyl ether, cyclopentyl methyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, and 2,5-dimethyltetrahydrofuran. These solvents can be used alone or in combination of two or more.

[0042] Among these solvents, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, butyl lactate, cyclohexanone, n-heptane, hexane, toluene, isopropyl ether, diisobutyl ether, diisoamyl ether, tert-butyl methyl ether, cyclopentyl methyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, etc. are preferred, and propylene glycol monomethyl ether, propylene glycol monoethyl ether, cyclopentyl methyl ether, propylene glycol monomethyl ether acetate, toluene, and isopropyl ether are particularly preferred.

[0043] The amount of organic solvent used is not particularly limited as long as it is an amount that can sufficiently dissolve the silicon-containing polymer to be treated, but is usually about 2 to 1,000 parts by mass, and preferably 4 to 100 parts by mass, per 100 parts by mass of the silicon-containing polymer to be treated.

[0044] The organic solvent contained in the treated silicon-containing polymer composition of the present application is preferably 100% of the solvent contained in the composition, but the composition may contain a solvent other than the organic solvent. For example, when the entire composition is taken as 100% by mass, the composition may contain a solvent other than the organic solvent (e.g., water) at a ratio of 1% by mass or less.

[0045] The weight average molecular weight (Mw) of the silicon-containing polymer contained in the treated silicon-containing polymer composition is usually 800 to 100,000, preferably 800 to 10,000, more preferably 800 to 5,000. The weight average molecular weight (Mw) is determined, for example, by the GPC method described in the Examples. The change in weight average molecular weight (Mw) before and after the ion exchange resin treatment is preferably 70 or less, and the smaller the better, but is preferably 60 or less, 50 or less, 40 or less, 30 or less, 20 or less, 10 or less, 5 or less, 3 or less, 1 or less, or 0.

[0046] The total remaining amount of 24 metal elements (Li, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Zr, Mo, Ag, Cd, Sn, Ba, W, Pb) in the silicon-containing polymer composition after the ion exchange resin treatment is preferably 1 ppb or less. The total remaining amount of 24 metal elements can be measured, for example, by inductively coupled plasma mass spectrometry (ICP-MS) described in the Examples.

[0047] The remaining amount of the total of the 24 metal elements is preferably 0.9 ppb or less. The remaining amount of the total of the 24 metal elements is preferably less than 0.8 ppb or 0.8 ppb or less. The remaining amount of the total of the 24 metal elements is preferably 0.7 ppb or less. The remaining amount of the total of the 24 metal elements is preferably 0.6 ppb or less. The remaining amount of the total of the 24 metal elements is preferably 0.5 ppb or less. The remaining amount of the total of the 24 metal elements is preferably 0.4 ppb or less. The remaining amount of the total of the 24 metal elements is preferably 0.3 ppb or less. The remaining amount of the total of the 24 metal elements is preferably 0.2 ppb or less. The remaining amount of the total of the 24 metal elements is preferably 0.1 ppb or less. The remaining amount of the total of the 24 metal elements is preferably 0.08 ppb or less. The remaining amount of the total of the 24 metal elements is preferably 0.05 ppb or less. The remaining amount of the total of the 24 metal elements is preferably 0.03 ppb or less. The total remaining amount of the 24 metal elements is preferably 0.01 ppb or less. The total remaining amount of the 24 metal elements is preferably 0 (below the detection limit).

[0048] <Silicon-containing resist underlayer film-forming composition> The silicon-containing resist underlayer film forming product of the present application includes a silicon-containing polymer composition treated by the method of the present application. Examples of the silicon-containing polymer contained in the treated silicon-containing polymer composition include known silicon-containing resist underlayer film forming compositions, such as WO2019 / 181873, WO2019 / 124514, WO2019 / 082934, WO2019 / 009413, WO2018 / 181989, WO2018 / 079599, WO2017 / 145809, WO2017 / 145808, WO2016 / 031563, etc., but are not limited thereto. Examples of the silicon-containing polymer contained in the silicon-containing resist underlayer film forming composition include silicon-containing polymers (polysiloxanes, etc.).

[0049] Preferred embodiments of the silicon-containing resist underlayer film-forming composition of the present application include the embodiments described in the above specification.

[0050] Examples of the silicon-containing polymer contained in the treated silicon-containing polymer composition include the polysiloxane contained in the coating polysiloxane composition described in WO2016 / 031563. The coating polysiloxane composition contains a hydrolysis condensate of hydrolyzable silanes, the hydrolyzable silanes having 2 to 3 hydrolyzable groups being contained in a proportion of 30 to 100 mol % of the total silanes in the coating polysiloxane composition.

[0051] The hydrolyzable silane has the formula (1): [ka] (In formula (1), R 1 is an alkyl group, an aryl group, a halogenated alkyl group, a halogenated aryl group, an alkoxyaryl group, an alkenyl group, or an organic group having an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, or a cyano group, and is bonded to a silicon atom by a Si-C bond; R 2represents an alkoxy group, an acyloxy group, or a halogen group, and a represents an integer of 0 to 2.) and contains hydrolyzable silanes in which a in formula (1) is 1 or 2 in a proportion of 30 to 100 mol % and hydrolyzable silanes in which a in formula (1) is 0 in a proportion of 0 to 70 mol % based on the total silanes.

[0052] The resist underlayer film-forming composition and the coating polysiloxane composition of the present application contain a hydrolysis condensate of a hydrolyzable silane, for example, as represented by formula (1), and a solvent, and may contain optional components such as acid, water, alcohol, a curing catalyst, an acid generator, other organic polymers, a light-absorbing compound, and a surfactant.

[0053] The solid content in the coating polysiloxane composition is, for example, 0.1 to 50 mass %, or 0.1 to 30 mass %, or 0.1 to 25 mass %, where the solid content is the total component of the coating polysiloxane composition excluding the solvent component.

[0054] The proportion of the hydrolyzable silane, its hydrolysate, and its hydrolysis condensate in the solid content is usually 20% by mass or more, for example, 50 to 100% by mass, 60 to 99% by mass, or 70 to 99% by mass.

[0055] The above-mentioned hydrolyzable silane, its hydrolyzate, and its hydrolysis condensate can also be used as a mixture thereof. The hydrolyzable silane can be hydrolyzed, and the obtained hydrolyzate can be condensed to use as a condensate. A partial hydrolyzate in which hydrolysis is not completely completed when obtaining the hydrolysis condensate, or a silane compound can be mixed with the hydrolysis condensate, and the mixture can be used. This condensate is a polymer having a polysiloxane structure.

[0056] Furthermore, examples of the silicon-containing polymer contained in the treated silicon-containing polymer composition include hydrolysis condensates obtained by hydrolyzing and condensing hydrolyzable silanes described in WO2019 / 082934.

[0057] The hydrolyzable silane has the formula (1-1): [ka] (In formula (1-1), R 1 R represents an organic group having a primary amino group, a secondary amino group, or a tertiary amino group, and is bonded to a silicon atom via a Si-C bond. 2 represents an alkyl group, an aryl group, a halogenated alkyl group, a halogenated aryl group, an alkoxyaryl group, an alkenyl group, an acyloxyalkyl group, or an organic group having an acryloyl group, a methacryloyl group, a mercapto group, an amino group, an amide group, a hydroxyl group, an alkoxy group, an ester group, a sulfonyl group, or a cyano group, or a group which is a combination thereof, and is bonded to a silicon atom by a Si-C bond. 1 and R 2 R may be bonded to form a ring structure. 3 represents an alkoxy group, an acyloxy group, or a halogen group. a represents an integer of 1, b represents an integer of 0 to 2, and a+b represents an integer of 1 to 3. The hydrolysis condensate contains an organic group having a salt structure with a counter anion derived from a strong acid and a counter cation derived from a primary ammonium group, a secondary ammonium group, or a tertiary ammonium group.

[0058] A preferred embodiment of the hydrolysis condensate is as described in WO2019 / 082934.

[0059] The alkyl group is a straight-chain or branched alkyl group having 1 to 10 carbon atoms, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, an s-butyl group, a t-butyl group, an n-pentyl group, a 1-methyl-n-butyl group, a 2-methyl-n-butyl group, a 3-methyl-n-butyl group, a 1,1-dimethyl-n-propyl group, a 1,2-dimethyl-n-propyl group, a 2,2-dimethyl-n-propyl group, a 1-ethyl-n-propyl group, an n-hexyl group, a 1-methyl-n-pentyl group, a 2 ... can be mentioned, for example, a 3-methyl-n-pentyl group, a 4-methyl-n-pentyl group, a 1,1-dimethyl-n-butyl group, a 1,2-dimethyl-n-butyl group, a 1,3-dimethyl-n-butyl group, a 2,2-dimethyl-n-butyl group, a 2,3-dimethyl-n-butyl group, a 3,3-dimethyl-n-butyl group, a 1-ethyl-n-butyl group, a 2-ethyl-n-butyl group, a 1,1,2-trimethyl-n-propyl group, a 1,2,2-trimethyl-n-propyl group, a 1-ethyl-1-methyl-n-propyl group, and a 1-ethyl-2-methyl-n-propyl group.

[0060] Cyclic alkyl groups can also be used. Examples of cyclic alkyl groups having 1 to 10 carbon atoms include cyclopropyl, cyclobutyl, 1-methylcyclopropyl, 2-methylcyclopropyl, cyclopentyl, 1-methylcyclobutyl, 2-methylcyclobutyl, 3-methylcyclobutyl, 1,2-dimethylcyclopropyl, 2,3-dimethylcyclopropyl, 1-ethylcyclopropyl, 2-ethylcyclopropyl, cyclohexyl, 1-methylcyclopentyl, 2-methylcyclopentyl, 3-methylcyclopentyl, 1-ethylcyclobutyl, 2-ethylcyclobutyl, 3-ethyl ... butyl group, 1,3-dimethyl-cyclobutyl group, 2,2-dimethyl-cyclobutyl group, 2,3-dimethyl-cyclobutyl group, 2,4-dimethyl-cyclobutyl group, 3,3-dimethyl-cyclobutyl group, 1-n-propyl-cyclopropyl group, 2-n-propyl-cyclopropyl group, 1-i-propyl-cyclopropyl group, 2-i-propyl-cyclopropyl group, 1,2,2-trimethyl-cyclopropyl group, 1,2,3-trimethyl-cyclopropyl group, 2,2,3-trimethyl-cyclopropyl group, 1-ethyl-2-methyl-cyclopropyl group, 2-ethyl-1-methyl-cyclopropyl group, 2-ethyl-2-methyl-cyclopropyl group, and 2-ethyl-3-methyl-cyclopropyl group.

[0061] The alkenyl group is an alkenyl group having 2 to 10 carbon atoms, and examples of such alkenyl groups include ethenyl, 1-propenyl, 2-propenyl, 1-methyl-1-ethenyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-ethylethenyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-n-propylethenyl, 1-methyl-1-butenyl, 1-methyl-2-butenyl, 1-methyl ethyl-3-butenyl group, 2-ethyl-2-propenyl group, 2-methyl-1-butenyl group, 2-methyl-2-butenyl group, 2-methyl-3-butenyl group, 3-methyl-1-butenyl group, 3-methyl-2-butenyl group, 3-methyl-3-butenyl group, 1,1-dimethyl-2-propenyl group, 1-i-propylethenyl group, 1,2-dimethyl-1-propenyl group, 1,2-dimethyl-2-propenyl group, 1-cyclopentenyl group, 2-cyclopentenyl group, 3-cyclopentenyl group, 1-hexenyl group, 2-hexenyl group, 3-hexenyl group, 4-hexenyl group , 5-hexenyl group, 1-methyl-1-pentenyl group, 1-methyl-2-pentenyl group, 1-methyl-3-pentenyl group, 1-methyl-4-pentenyl group, 1-n-butylethenyl group, 2-methyl-1-pentenyl group, 2-methyl-2-pentenyl group, 2-methyl-3-pentenyl group, 2-methyl-4-pentenyl group, 2-n-propyl-2-propenyl group, 3-methyl-1-pentenyl group, 3-methyl-2-pentenyl group, 3-methyl-3-pentenyl group, 3-methyl-4-pentenyl group, 3-ethyl-3-butenyl group, 4-methyl-1-pentenyl group, 4-methyl-2-pentenyl group, 4-methyl-3-pentenyl group, 4-methyl-4-pentenyl group, 1,1-dimethyl-2-butenyl group, 1,1-dimethyl-3-butenyl group, 1,2-dimethyl-1-butenyl group, 1,2-dimethyl-2-butenyl group, 1,2-dimethyl-3-butenyl group, 1-methyl-2-ethyl-2-propenyl group, 1-s-butylethenyl group, 1,3-dimethyl-1-butenyl group, 1,3-dimethyl-2-butenyl group, 1,3-dimethyl-3-butenyl group, 1-i-butylethenyl group, 2,2-dimethyl-3-butenyl group, 2,3-dimethyl-1-butenyl group, 2,3-dimethyl-2-butenyl group, 2,3-dimethyl-3-butenyl group, 2-i-propyl-2-propenyl group, 3,3-dimethyl-1-butenyl group, 1-ethyl-1-butenyl group, 1-ethyl-2-butenyl group, 1-ethyl-3-butenyl group, 1-n-propyl-1-propenyl group, 1-n-propyl-2-propenyl group, 2-ethyl-1-butenyl group, 2-ethyl-2-butenyl group, 2-ethyl-3-butenyl group, 1,1,2-trimethyl-2-propenyl group, 1-t-butylethenyl group, 1-methyl-1-ethyl-2-propenyl group, 1-ethyl-2-methyl-1-propenyl group, 1-ethyl-2-methyl-2-propenyl group, 1-i-propyl-1-propenyl group Examples of the cyclopentyl group include 1-methyl-2-cyclopentenyl group, 1-methyl-3-cyclopentenyl group, 2-methyl-1-cyclopentenyl group, 2-methyl-2-cyclopentenyl group, 2-methyl-3-cyclopentenyl group, 2-methyl-4-cyclopentenyl group, 2-methyl-5-cyclopentenyl group, 2-methylene-cyclopentyl group, 3-methyl-1-cyclopentenyl group, 3-methyl-2-cyclopentenyl group, 3-methyl-3-cyclopentenyl group, 3-methyl-4-cyclopentenyl group, 3-methyl-5-cyclopentenyl group, 3-methylene-cyclopentyl group, 1-cyclohexenyl group, 2-cyclohexenyl group, and 3-cyclohexenyl group.

[0062] The aryl group includes aryl groups having 6 to 20 carbon atoms, such as a phenyl group, an o-methylphenyl group, a m-methylphenyl group, a p-methylphenyl group, an o-chlorophenyl group, a m-chlorophenyl group, a p-chlorophenyl group, an o-fluorophenyl group, a p-mercaptophenyl group, an o-methoxyphenyl group, a p-methoxyphenyl group, a p-aminophenyl group, a p-cyanophenyl group, an α-naphthyl group, a β-naphthyl group, an o-biphenylyl group, a m-biphenylyl group, a p-biphenylyl group, a 1-anthryl group, a 2-anthryl group, a 9-anthryl group, a 1-phenanthryl group, a 2-phenanthryl group, a 3-phenanthryl group, a 4-phenanthryl group, and a 9-phenanthryl group.

[0063] Examples of the organic group having an epoxy group include glycidoxymethyl, glycidoxyethyl, glycidoxypropyl, glycidoxybutyl, and epoxycyclohexyl.

[0064] Examples of the organic group having an acryloyl group include acryloylmethyl, acryloylethyl, and acryloylpropyl.

[0065] Examples of the organic group having a methacryloyl group include methacryloylmethyl, methacryloylethyl, and methacryloylpropyl.

[0066] Examples of the organic group having a mercapto group include ethyl mercapto, butyl mercapto, hexyl mercapto, and octyl mercapto.

[0067] Examples of the organic group having a cyano group include cyanoethyl and cyanopropyl.

[0068] The alkoxy group includes an alkoxy group having a straight-chain, branched or cyclic alkyl moiety having 1 to 20 carbon atoms, such as a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, an i-butoxy group, an s-butoxy group, a t-butoxy group, an n-pentyloxy group, a 1-methyl-n-butoxy group, a 2-methyl-n-butoxy group, a 3-methyl-n-butoxy group, a 1,1-dimethyl-n-propoxy group, a 1,2-dimethyl-n-propoxy group, a 2,2-dimethyl-n-propoxy group, a 1-ethyl ... n-propoxy, n-hexyloxy, 1-methyl-n-pentyloxy, 2-methyl-n-pentyloxy, 3-methyl-n-pentyloxy, 4-methyl-n-pentyloxy, 1,1-dimethyl-n-butoxy, 1,2-dimethyl-n-butoxy, 1,3-dimethyl-n-butoxy, 2,2-dimethyl-n-butoxy, 2,3-dimethyl-n-butoxy, 3,3-dimethyl-n-butoxy, 1-ethyl-n-butoxy, 2-ethyl-n-butoxy, 1,1,2-trimethyl-n-propoxy, Examples of cyclic alkoxy groups include cyclopropoxy, cyclobutoxy, 1-methyl-cyclopropoxy, 2-methyl-cyclopropoxy, cyclopentyloxy, 1-methyl-cyclobutoxy, 2-methyl-cyclobutoxy, 3-methyl-cyclobutoxy, 1,2-dimethyl-cyclopropoxy, 2,3-dimethyl-cyclopropoxy, 1-ethyl-cyclopropoxy, 2-ethyl-cyclopropoxy, cyclohexyloxy, 1-methyl-cyclopentyloxy, 2-methyl-cyclopentyloxy, 3-methyl-cyclopentyloxy, 1-ethyl-cyclobutoxy, 2-ethyl-cyclobutoxy, 3-ethyl-cyclobutoxy, 1,2-dimethyl-cyclobutoxy, 1,3-dimethyl-cyclobutoxy, 2,2-dimethyl-cyclobutoxy, 2,3-dimethyl-cyclobutoxy, 2,4-dimethyl-cyclobutoxy, 3,Examples of the cyclopropoxy group include 3-dimethyl-cyclobutoxy group, 1-n-propyl-cyclopropoxy group, 2-n-propyl-cyclopropoxy group, 1-i-propyl-cyclopropoxy group, 2-i-propyl-cyclopropoxy group, 1,2,2-trimethyl-cyclopropoxy group, 1,2,3-trimethyl-cyclopropoxy group, 2,2,3-trimethyl-cyclopropoxy group, 1-ethyl-2-methyl-cyclopropoxy group, 2-ethyl-1-methyl-cyclopropoxy group, 2-ethyl-2-methyl-cyclopropoxy group, and 2-ethyl-3-methyl-cyclopropoxy group.

[0069] Examples of the acyloxy group include the acyloxy groups having 2 to 20 carbon atoms, such as a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an i-propylcarbonyloxy group, an n-butylcarbonyloxy group, an i-butylcarbonyloxy group, an s-butylcarbonyloxy group, a t-butylcarbonyloxy group, an n-pentylcarbonyloxy group, a 1-methyl-n-butylcarbonyloxy group, a 2-methyl-n-butylcarbonyloxy group, a 3-methyl-n-butylcarbonyloxy group, a 1,1-dimethyl-n-propylcarbonyloxy group, a 1,2-dimethyl-n-propylcarbonyloxy group, a 2,2-dimethyl-n-propylcarbonyloxy group, a 1-ethyl-n-propylcarbonyloxy group, an n-hexylcarbonyloxy group, a 1-methyl-n-pentylcarbonyloxy group, a 2-methyl-n-pentyl carbonyloxy group, 3-methyl-n-pentylcarbonyloxy group, 4-methyl-n-pentylcarbonyloxy group, 1,1-dimethyl-n-butylcarbonyloxy group, 1,2-dimethyl-n-butylcarbonyloxy group, 1,3-dimethyl-n-butylcarbonyloxy group, 2,2-dimethyl-n-butylcarbonyloxy group, 2,3-dimethyl-n-butylcarbonyloxy group, 3,3-dimethyl-n-butylcarbonyloxy group, 1-ethyl-n-butylcarbonyloxy group, 2-ethyl-n-butylcarbonyloxy group, 1,1,2-trimethyl-n-propylcarbonyloxy group, 1,2,2-trimethyl-n-propylcarbonyloxy group, 1-ethyl-1-methyl-n-propylcarbonyloxy group, 1-ethyl-2-methyl-n-propylcarbonyloxy group, phenylcarbonyloxy group, and tosylcarbonyloxy group.

[0070] The acyloxyalkyl group may be a combination of the above-mentioned alkyl group and the below-mentioned acyloxy group, such as an acetoxymethyl group, an acetoxyethyl group, or an acetoxypropyl group.

[0071] The halogen group includes fluorine, chlorine, bromine, iodine, and the like.

[0072] The examples of groups given above also apply to the alkyl, aryl, alkoxy and halogen moieties of the halogenated alkyl group, halogenated aryl group and alkoxyaryl group.

[0073] <Method of Manufacturing Semiconductor Device> Hereinafter, the use of the silicon-containing resist underlayer film forming composition used in the present invention will be described.

[0074] The silicon-containing resist underlayer film forming composition of the present invention is applied onto a substrate (e.g., a silicon wafer substrate, a silicon / silicon dioxide-coated substrate, a silicon nitride substrate, a glass substrate, an ITO substrate, a polyimide substrate, and a substrate coated with a low dielectric constant material (low-k material)) used in the manufacture of a semiconductor device by a suitable application method such as a spinner or a coater, and then baked to form a silicon-containing resist underlayer film. Baking conditions are appropriately selected from a baking temperature of 80°C to 250°C and a baking time of 0.3 to 60 minutes. Preferably, the baking temperature is 150°C to 250°C and the baking time is 0.5 to 2 minutes.

[0075] Here, the thickness of the underlayer film formed is, for example, 10 to 1000 nm, or 20 to 500 nm, or 50 to 300 nm, or 100 to 200 nm. In the present invention, the silicon-containing resist underlayer film is an underlayer film of an EUV resist, and the thickness of the silicon-containing resist underlayer film can be 1 nm to 30 nm, or 1 nm to 20 nm, or 1 nm to 5 nm.

[0076] Then, for example, a photoresist layer is formed on the silicon-containing resist underlayer film. The photoresist layer can be formed by a well-known method, that is, by applying a photoresist composition solution onto the underlayer film and baking it. The thickness of the photoresist is, for example, 50 to 10,000 nm, or 100 to 2,000 nm, or 200 to 1,000 nm. In the present invention, after forming an organic underlayer film on a substrate, the silicon-containing resist underlayer film used in the present invention can be formed thereon, and then coated with a photoresist. This narrows the pattern width of the photoresist, and even if the photoresist is thinly coated to prevent pattern collapse, the substrate can be processed by selecting an appropriate etching gas. For example, a fluorine-based gas having a sufficiently high etching rate for a photoresist can be used as an etching gas to process the silicon-containing resist underlayer film used in the present invention, an oxygen-based gas having a sufficiently high etching rate for the silicon-containing resist underlayer film used in the present invention can be used as an etching gas to process an organic underlayer film, and a fluorine-based gas having a sufficiently high etching rate for an organic underlayer film can be used as an etching gas to process a substrate.

[0077] The photoresist formed on the silicon-containing resist underlayer film used in the present invention is not particularly limited as long as it is sensitive to the light used for exposure. Both negative photoresists and positive photoresists can be used. There are positive photoresists made of novolac resin and 1,2-naphthoquinone diazide sulfonic acid ester, chemically amplified photoresists made of a binder having a group that decomposes with acid to increase the alkaline dissolution rate and a photoacid generator, chemically amplified photoresists made of a low molecular compound that decomposes with acid to increase the alkaline dissolution rate of the photoresist, an alkali-soluble binder, and a photoacid generator, and chemically amplified photoresists made of a binder having a group that decomposes with acid to increase the alkaline dissolution rate, a low molecular compound that decomposes with acid to increase the alkaline dissolution rate of the photoresist, and a photoacid generator. For example, there are APEX-E (trade name) manufactured by Shipley Co., Ltd., PAR710 (trade name) manufactured by Sumitomo Chemical Co., Ltd., and SEPR430 (trade name) manufactured by Shin-Etsu Chemical Co., Ltd. Further, there can be mentioned fluorine-containing polymer photoresists as described in, for example, Proc. SPIE, Vol. 3999, 330-334 (2000), Proc. SPIE, Vol. 3999, 357-364 (2000), and Proc. SPIE, Vol. 3999, 365-374 (2000).

[0078] Next, in the present invention, exposure is performed through a predetermined mask. For exposure, a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm), an F2 excimer laser (wavelength 157 nm), or the like can be used. After exposure, post exposure bake can be performed as necessary. The post exposure bake is performed under appropriately selected conditions from a heating temperature of 70°C to 150°C and a heating time of 0.3 to 10 minutes.

[0079] In addition, in the present invention, a resist for electron beam lithography or a resist for EUV lithography can be used instead of a photoresist as a resist. Either a negative type or a positive type can be used as the electron beam resist. There are chemically amplified resists consisting of an acid generator and a binder having a group that decomposes with an acid to change the alkaline dissolution rate, a chemically amplified resist consisting of an alkali-soluble binder, an acid generator, and a low molecular weight compound that decomposes with an acid to change the alkaline dissolution rate of the resist, a chemically amplified resist consisting of an acid generator, a binder having a group that decomposes with an acid to change the alkaline dissolution rate, and a low molecular weight compound that decomposes with an acid to change the alkaline dissolution rate of the resist, a non-chemically amplified resist consisting of a binder having a group that decomposes with an electron beam to change the alkaline dissolution rate, and a non-chemically amplified resist consisting of a binder having a site that is cut by an electron beam to change the alkaline dissolution rate. When these electron beam resists are used, a resist pattern can be formed in the same way as when a photoresist is used, with an electron beam as the irradiation source. In addition, a methacrylate resin-based resist can be used as the EUV resist.

[0080] Next, development is carried out with a developer (for example, an alkaline developer). As a result, when a positive photoresist is used, the photoresist in the exposed portion is removed, and a photoresist pattern is formed.

[0081] Examples of the developing solution include an aqueous solution of an alkali metal hydroxide such as potassium hydroxide or sodium hydroxide, an aqueous solution of a quaternary ammonium hydroxide such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, or choline, or an aqueous solution of an amine such as ethanolamine, propylamine, or ethylenediamine. Furthermore, a surfactant or the like can be added to these developing solutions. The developing conditions are appropriately selected from a temperature of 5 to 50° C. and a time of 10 to 600 seconds.

[0082] In the present invention, an organic solvent can be used as a developer. After exposure, development is performed with the developer (solvent). As a result, when a positive photoresist is used, the photoresist in the unexposed area is removed, and a photoresist pattern is formed.

[0083] Examples of the developing solution include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol mono Propyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyric acid Examples of the aryl esters include ethyl esters, propyl esters, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, and propyl 3-methoxypropionate.Furthermore, a surfactant may be added to these developers. The development conditions are appropriately selected from a temperature of 5 to 50° C. and a time of 10 to 600 seconds.

[0084] Then, the silicon-containing resist underlayer film (middle layer) of the present invention is removed using the pattern of the photoresist (upper layer) thus formed as a protective film, and then the organic underlayer film (lower layer) is removed using the film consisting of the patterned photoresist and the silicon-containing resist underlayer film (middle layer) of the present invention as a protective film.Finally, the semiconductor substrate is processed using the patterned silicon-containing resist underlayer film (middle layer) of the present invention and the organic underlayer film (lower layer) as a protective film.

[0085] First, the silicon-containing resist underlayer film (middle layer) of the present invention from the portion where the photoresist has been removed is removed by dry etching to expose the semiconductor substrate. For dry etching of the silicon-containing resist underlayer film of the present invention, gases such as tetrafluoromethane (CF4), perfluorocyclobutane (C4F8), perfluoropropane (C3F8), trifluoromethane, carbon monoxide, argon, oxygen, nitrogen, sulfur hexafluoride, difluoromethane, nitrogen trifluoride, chlorine trifluoride, chlorine, trichloroborane, and dichloroborane can be used.

[0086] It is preferable to use a halogen-based gas for dry etching of the silicon-containing resist underlayer film.

[0087] In dry etching with halogen-based gas, photoresist made of organic material is difficult to remove. In contrast, the silicon-containing resist underlayer film of the present invention, which contains a large amount of silicon atoms, is quickly removed by halogen-based gas. Therefore, it is possible to suppress the decrease in the thickness of the photoresist caused by dry etching of the silicon-containing resist underlayer film. As a result, it becomes possible to use the photoresist in a thin film. Dry etching of the silicon-containing resist underlayer film is preferably performed with fluorine-based gas, and examples of the fluorine-based gas include tetrafluoromethane (CF4), perfluorocyclobutane (C4F8), perfluoropropane (C3F8), trifluoromethane, and difluoromethane (CH2F2), etc.

[0088] Thereafter, the organic underlayer film is removed using the patterned photoresist and the film made of the silicon-containing resist underlayer film of the present invention as protective films. The organic underlayer film (underlayer) is preferably removed by dry etching with an oxygen-based gas. This is because the silicon-containing resist underlayer film of the present invention, which contains a large amount of silicon atoms, is difficult to remove by dry etching with an oxygen-based gas.

[0089] Finally, the semiconductor substrate is processed, preferably by dry etching using a fluorine-based gas.

[0090] Examples of fluorine-based gases include tetrafluoromethane (CF4), perfluorocyclobutane (C4F8), perfluoropropane (C3F8), trifluoromethane, and difluoromethane (CH2F2).

[0091] In addition, ion implantation can be performed as the processing of the substrate. After the processing of the substrate, the mask layer is removed with a chemical solution containing hydrogen peroxide, and the semiconductor device is manufactured. The mask layer is a resist or an organic underlayer film including a silicon-containing resist underlayer film.

[0092] In addition, in the present invention, an organic anti-reflective film can be formed on the upper layer of the silicon-containing resist underlayer film before forming a photoresist.The anti-reflective film composition used therein is not particularly limited, and can be arbitrarily selected from those conventionally used in the lithography process, and can be formed by conventional methods, such as coating with a spinner or coater and baking.

[0093] In the present invention, the substrate to which the silicon-containing resist underlayer film-forming composition is applied may have an organic or inorganic anti-reflective film formed on its surface by a CVD method or the like, and the silicon-containing resist underlayer film of the present invention may be formed thereon.

[0094] In the present invention, the silicon-containing resist underlayer film formed from the silicon-containing resist underlayer film forming composition may also have absorption of light depending on the wavelength of the light used in the lithography process.In such a case, it can function as an anti-reflection film having the effect of preventing reflected light from the substrate.Furthermore, the silicon-containing resist underlayer film used in the present invention can also be used as a layer for preventing the interaction between the substrate and the photoresist, a layer having a function of preventing the adverse effect on the substrate of the material used in the photoresist or the substance generated during exposure to the photoresist, a layer having a function of preventing the diffusion of the substance generated from the substrate during heating and baking into the upper photoresist, and a barrier layer for reducing the poisoning effect of the photoresist layer by the dielectric layer of the semiconductor substrate.

[0095] In addition, the silicon-containing resist underlayer film formed from the silicon-containing resist underlayer film forming composition can be applied to a substrate having a via hole used in a dual damascene process, and can be used as a filling material capable of filling the hole without gaps. It can also be used as a planarizing material for planarizing the surface of a semiconductor substrate having irregularities.

[0096] In addition to its function as a hard mask, the underlayer film of the EUV resist can also be used for the following purposes. As an anti-reflection film for the EUV resist, which can prevent unwanted exposure light, such as the above-mentioned UV or DUV (ArF light, KrF light), from being reflected from the substrate or interface during EUV exposure (wavelength 13.5 nm) without intermixing with the EUV resist, the above silicon-containing resist underlayer film-forming composition can be used. It can efficiently prevent reflection under the EUV resist. When used as the EUV resist underlayer film, the process can be carried out in the same manner as the underlayer film for photoresist.

Examples

[0097] Next, examples will be given to specifically explain the content of the present invention, but the present invention is not limited thereto.

[0098] <GPC (Gel Permeation Chromatography) analysis conditions> The molecular weights shown in the examples described later are the measurement results by GPC, and the measurement conditions are as follows.

[0099] Apparatus: HLC-8320GPC (Tosoh Corporation) Column: KF-G (4.6 mm I.D. x 100 mm) + KF-803L (8.0 mm I.D. x 300 mm) + KF-802 (8.0 mm I.D. x 300 mm) + KF801 (8.0 mm I.D. x 300 mm) (Showa Denko K.K.) Eluent: THF (HPLC grade) Flow rate: 1.0 ml / min. Column temperature: 40 °C Detector: RI (differential refractometer) Injection volume: 30 μL Sample concentration: Adjusted to a solid content concentration of 1.0% Dilution solvent: Propylene glycol monoethyl ether (PGEE) Standard sample: Polystyrene, molecular weights 47,200, 13,300, 3,180, 1,390, 580 Calibration curve creation method: Cubic curve Elimination time: 0 minutes <Explanation of abbreviations> (Organic solvent) PGEE: Propylene glycol monoethyl ether PGMEA: Propylene glycol monomethyl ether acetate

[0100] <Treatment of the Treated Silicon-Containing Polymer (A) Composition with Ion Exchange Resin> [Example 1] To 95 g of a PGEE / PGMEA solution (solid content: approximately 13 mass%) of a silicon-containing polymer (A) produced by a method according to Synthesis Example 3 of WO2016 / 031563, 5 g of ORLITE DS-1 (product name) manufactured by Organo Corporation, which is a gel-type strongly acidic cation exchange resin obtained by washing with a PGEE / PGMEA solution and replacing the water content in the resin, was added based on the dry resin, and the mixture was stirred at room temperature for 24 hours, after which the resin was removed by decantation to obtain a treated solution (purified solution).

[0101] The resulting purified silicon-containing polymer (A) solution was measured for molecular weight by GPC, and for residual metal amount by inductively coupled plasma mass spectrometry (ICP-MS (Agilent 7500: manufactured by Agilent Technologies, Inc.)). The results of measuring the molecular weight and residual metal amount are shown in Table 1. The residual metal amount is the value assuming that 1 mg of metal is dissolved in 1 kg of silicon-containing polymer solution, and the metal concentration is 1000 ppb.

[0102] The 24 elements for which the amount of remaining metals was measured are as follows: Li, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Zr, Mo, Ag, Cd, Sn, Ba, W, and Pb.

[0103] [Comparative Example 1] The same treatment was carried out using ORLITE DS-4, a strongly acidic cation exchange resin having an MR type structure manufactured by Organo Corporation, instead of the gel-type strongly acidic cation exchange resin manufactured by Organo Corporation used in Example 1. The results are shown in Table 1.

[0104] [Comparative Example 2] The same treatment was carried out using ORLITE DS-7 manufactured by Organo Corporation, which is a mixture of a strongly acidic cation exchange resin having an MR type structure and a strongly basic anion exchange resin having an MR type structure, instead of the gel-type strongly acidic cation exchange resin manufactured by Organo Corporation used in Example 1. The results are shown in Table 1. The amount of resin added was set so that the amount of strongly acidic cation exchange resin in the mixture was the same as in Example 1.

[0105] [Table 1] As shown in Table 1, when the ion exchange resin of Example 1 was used, the remaining metal impurities could be removed while suppressing the denaturation of the silicon-containing polymer, whereas when the ion exchange resins of Comparative Examples 1 and 2 were used, the denaturation of the silicon-containing polymer (change in ΔMw) was large, and it was shown that this was not practical. The denaturation of the silicon-containing polymer in the ion exchange process is believed to be due to the ion exchange resin acting as a catalyst to promote the polymerization reaction of the silicon-containing polymer. The catalytic action of the ion exchange resin depends on the contact area between the reactant and the ion exchange resin surface and the type of functional group on the ion exchange resin surface. The results of Example 1 and Comparative Example 1 suggest that DS-1 is a gel-type ion exchange resin that has only micropores (pore diameter: 10-10 Å), so that the silicon-containing polymer, which is a polymer, cannot penetrate into the resin pores, and DS-4 is an MR-type ion exchange resin that has mesopores-macropores (pore diameter: several hundred Å~), so that the silicon-containing polymer can also penetrate into the pores, and the contact area between the silicon-containing polymer and the ion exchange resin surface is relatively large. Furthermore, the results of Example 1 and Comparative Example 2 suggest that the basic functional groups on the surface of the anion exchange resin have a strong catalytic effect in promoting the polymerization reaction of the silicon-containing polymer.

[0106] [Example 2] Using the same ion exchange resin as in Example 1 and a newly produced polymer solution to be treated, a treated solution (purified solution) was obtained by column flow ion exchange. The flow rate of the polymer solution to be treated was adjusted so that the spatial velocity (SV[1 / h]: space velocity) was 2 with respect to the volume of the resin packed bed in the column, i.e., the residence time of the solution to be treated was 30 minutes. The operation was carried out at room temperature. The results of measuring the molecular weight and the amount of remaining metal are shown in Table 2.

[0107] [Table 2] As shown in Table 2, when the ion exchange resin of Example 2 was used in the column flow system, it was possible to remove the remaining metal impurities while suppressing the denaturation of the silicon-containing polymer. [Industrial Applicability]

[0108] The present invention provides an industrially useful method for purifying silicon-containing polymers, which are used in lithography processes in the manufacture of semiconductor devices, and which have reduced levels of defect-causing metal impurities.

Claims

1. A method for producing a silicon-containing polymer composition to be treated, which comprises treating a silicon-containing polymer composition to be treated, which comprises a silicon-containing polymer obtained by polymerizing an alkoxysilicon compound selected from the following formulae (2-1) to (2-28) and an organic solvent, with a gel-type ion exchange resin, and the organic solvent accounts for 100% of the solvent contained in the silicon-containing polymer composition to be treated, thereby reducing the change in weight-average molecular weight (ΔMw) of the silicon-containing polymer before and after treatment. 【Chemical 1】

2. A method for producing a silicon-containing polymer composition as described in claim 1, wherein the weight average molecular weight change (ΔMw) is 70 or less.

3. A method for producing a silicon-containing polymer composition described in claim 1 or 2, wherein the ion exchange resin is a cation exchange resin.

4. A method for producing a silicon-containing polymer composition described in any one of claims 1 to 3, wherein the ion exchange resin has a strongly acidic functional group.

5. A method for producing a silicon-containing polymer composition described in any one of claims 1 to 4, wherein the ion exchange resin has a sulfonic acid group as a functional group.

6. A method for producing a silicon-containing polymer composition described in any one of claims 1 to 5, wherein the total remaining amount of 24 metal elements after the ion exchange treatment is 1 ppb or less.

7. The method for producing a silicon-containing polymer composition according to claim 1, wherein the treatment is carried out in a batch or column flow manner.

8. The method for producing a silicon-containing polymer composition according to claim 1, wherein the weight average molecular weight (Mw) of the treated silicon-containing polymer is 800 to 100,000.

9. A method for producing a silicon-containing polymer composition described in any one of claims 1 to 8, wherein the 24 metal elements are Li, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Zr, Mo, Ag, Cd, Sn, Ba, W, and Pb.

10. A silicon-containing polymer composition in which the change in weight average molecular weight (ΔMw) of the silicon-containing polymer before and after treatment with a gel-type cation exchange resin is 70 or less, and the total amount of 24 metal elements remaining after ion exchange treatment is 1 ppb or less.

11. A silicon-containing resist underlayer film-forming composition comprising the silicon-containing polymer composition of claim 10.

12. A method for manufacturing a semiconductor device, comprising the steps of applying the silicon-containing resist underlayer film-forming composition according to claim 11 onto a semiconductor substrate and baking the composition to form a silicon-containing resist underlayer film, applying a resist film-forming composition onto the underlayer film to form a resist film, exposing the resist film, developing the resist film after exposure to obtain a patterned resist film, etching the silicon-containing resist underlayer film with the patterned resist film to pattern it, and processing a semiconductor substrate with the patterned resist film and the silicon-containing resist underlayer film.

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