Resist composition and patterning process

A resist film having a thickness of 3 to 50 μm, comprising:

• (A) an alkali-insoluble or substantially insoluble polymer having acidic functional groups protected with acid labile groups, which polymer becomes alkali-soluble upon elimination of the acid-labile groups;
• (B) a photoacid generator selected from the group consisting of oxime sulfonate compounds, onium salts, β-ketosulfone derivatives, diazomethane derivatives, disulfone derivatives, sulfonic acid ester derivatives and imidoyl sulfonate derivatives;
• and
• (C) a 1,2-naphthoquinonediazidosulfonyl group-bearing compound.

A resist film having a thickness of 3 to 50 μm, comprising:

• (A) 80 parts by weight of an alkali-insoluble or substantially insoluble polymer containing recurring units of general formula (1) below and has a weight-average molecular weight of 3,000 to 300,000,
• wherein R1 is hydrogen or methyl, R2 is a straight, branched or cyclic alkyl of 1 to 8 carbons, and x is 0 or a positive integer and y is a positive integer satisfying x+y≦5;
• in which the hydrogen atoms on some of the phenolic hydroxyl groups have been substituted with at least one type of acid labile group, the amount of acid labile groups averages more than 0 mol %, but not more than 80 mol %, of all the phenolic hydroxyl group hydrogens in formula (1), and the acid labile group is selected from the class consisting of groups of the following general formulas (7) and (8), tertiary alkyl groups, trialkylsilyl groups, and ketoalkyl groups:
• wherein R9 and R10 are each independently a hydrogen or a straight or branched alkyl of 1 to 6 carbons, and R11 is a straight, branched or cyclic alkyl of 1 to 10 carbons, or a pair of R9 and R10, a pair of R9 and R11, or a pair of R10 and R11 may together form a ring, in which case R9, R10 and R11 are each independently a straight or branched alkylene of 1 to 6 carbons, R12 is a tertiary alkyl of 4 to 12 carbons, and the letter a is an integer from 0 to 6;
• (B) 0.5 to 15 parts by weight of a photoacid generator selected from the group consisting of oxime sulfonate compounds, onium salts, β-ketosulfone derivatives, diazomethane derivatives, disulfone derivatives, sulfonic acid ester derivatives and imidoyl sulfonate derivatives;
• and
• (C) 0.1 to 15 parts by weight of a 1,2-naphthoquinonediazidosulfonyl group-bearing compound.

A resist composition for exposure to ultraviolet light having a wavelength of at least 300 nm, comprising:

• (A) 80 parts by weight of an alkali-insoluble or substantially insoluble polymer having acidic functional groups protected with acid labile groups, which polymer becomes alkali-soluble upon elimination of the acid-labile groups;
• (B) 0.5 to 15 parts by weight of a photoacid generator selected from the group consisting of oxime sulfonate compounds, onium salts, β-ketosolfone derivatives, diazomethane derivatives, disulfone derivatives, sulfonic acid ester derivatives and imidoyl sulfonate derivatives;
• and
• (C) 0.1 to 15 parts by weight of a 1,2-napthoquinonediazidosulfonyl group-bearing compound obtained by introducing 1,2-napthoquinonediazidosulfonyl group into a phenolic hydroxyl group-bearing ballast molecule of formula 2, or into a novolac resin comprising recurring units of formula (11) below and having a weight-average molecular weight in a range of 2,000 to 20,000:
• wherein R3 to R8 are each independently hydrogen, methyl, or a group of formula (3) or (4) below:
• m is an integer from 0 to 2 and n is an integer from 0 to 2, with the proviso that m is 1 or 2 if n is 0;
• when m is 1 and n is 0, A is hydrogen, methyl or a group of formula (3);
• when m is 2 and n is 0, one A moiety is methylene or a group of formula (5) below and the other A moiety is hydrogen, methyl or a group of formula (3);
• when n is 1, A is methylene or a group of formula (5);
• when m is 1 and n is 2, A is methane or a group of formula (6) below;
• and when m is 2 and n is 2, one A moiety is methylene or a group of formula (5) and the other A moiety is methane or a group of formula (6):
• wherein p, q, r, s, t, u and v are each an integer from 0 to 3, such that p+q≦5, r+s≦4 and u+v≦3,
• wherein m is an integer from 0 to 3.

A patterning process comprising the steps of

• (i) applying onto a substrate a resist composition comprising:
• (A) 80 parts by weight of an alkali-insoluble or substantially insoluble polymer having acidic functional groups protected with acid labile groups, which polymer becomes alkali-soluble upon elimination of the acid-labile groups:
• (B) 0.5 to 15 parts by weight of a photoacid generator selected from the group consisting of oxime sulfonate compounds, onium salts, β-ketosulfone derivatives, diazomethane derivatives, disulfone derivatives, sulfonic acid ester derivatives and imidoyl sulfonate derivatives;
• and
• (C) 0.1 to 15 parts by weight of a 1,2-napthoquinonediazidosulfonyl group-bearing compound so that a resist film has a thickness of 3 to 50 μm;
• (ii) heat treating the resist film at 90 to 130° C. for 1 to 10 minutes, then exposing it through a photomask to ultraviolet light having a wavelength of at least 300 nm;
• and
• (iii) heat treating the exposed resist composition at 90 to 130° C. for 1 to 5 minutes if necessary, then developing it with a developer.

A substrate having applied thereto a resist film, in a thickness of 3 to 50 μm, said resist film comprising:

• (A) 80 parts by weight of an alkali-insoluble or substantially insoluble polymer containing recurring units of general formula (1) below and has a weight-average molecular weight of 3,000 to 300,000,
• wherein R1 is hydrogen or methyl, R2 is a straight, branched or cyclic alkyl of 1 to 8 carbons, and x is 0 or a positive integer and y is a positive integer satisfying x+y≦5;
• in which the hydrogen atoms on some of the phenolic hydroxyl groups have been substituted with at least one type of acid labile group, the amount of acid labile groups averages more than 0 mol %, but not more than 80 mol %, of all the phenolic hydroxyl group hydrogens in formula (1), and the acid labile group is selected from the class consisting of groups of the following general formulas (7) and (8), tertiary alkyl groups, trialkylsilyl groups, and ketoalkyl groups:
• wherein R9 and R10 are each independently a hydrogen or a straight or branched alkyl of 1 to 6 carbons, and R11 is a straight, branched or cyclic alkyl of 1 to 10 carbons, or a pair of R9 and R10, a pair of R9 and R11, or a pair of R10 and R11 may together form a ring, in which case R9, R10 and R11 are each independently a straight or branched alkylene of 1 to 6 carbons, R12 is a tertiary alkyl of 4 to 12 carbons, and the letter a is an integer from 0 to 6;
• (B) 0.5 to 15 parts by weight of a photoacid generator selected from the group consisting of oxime sulfonate compounds, onium salts, β-ketosulfone derivatives, diazomethane derivatives, disulfone derivatives, sulfonic acid ester derivatives and imidoyl sulfonate derivatives:
• and
• (C) 0.1 to 15 parts by weight of a 1,2-naphthoquinonediazidosulfonyl group-bearing compound.

A substrate having applied thereto a resist film, in a thickness of 3 to 50 μm, said resist film comprising:

• (A) 80 parts by weight of an alkali-insoluble or substantially insoluble polymer having acidic functional groups protected with acid labile groups, which polymer becomes alkali-soluble upon elimination of the acid-labile groups;
• (B) 0.5 to 15 parts by weight of a photoacid generator selected from the group consisting of oxime sulfonate compounds, onium salts, β-ketosolfone derivatives, diazomethane derivatives, disulfone derivatives, sulfonic acid ester derivatives and imidoyl sulfonate derivatives;
• and
• (C) 0.1 to 15 parts by weight of a 1,2-napthoquinonediazidosulfonyl group-bearing compound obtained by introducing 1,2-napthoquinonediazidosulfonyl group into a phenolic hydroxyl group-bearing ballast molecule of formula 2, or into a novolac resin comprising recurring units of formula (11) below and having a weight-average molecular weight in a range of 2,000 to 20,000:
• wherein R3 to R8 are each independently hydrogen, methyl, or a group of formula (3) or (4) below:
• m is an integer from 0 to 2 and n is an integer from 0 to 2, with the proviso that m is 1 or 2 if n is 0;
• when m is 1 and n is 0, A is hydrogen, methyl or a group of formula (3);
• when m is 2 and n is 0, one A moiety is methylene or a group of formula (5) below and the other A moiety is hydrogen, methyl or a group of formula (3);
• when n is 1, A is methylene or a group of formula (5);
• when m is 1 and n is 2, A is methane or a group of formula (6) below;
• and when m is 2 and n is 2, one A moiety is methylene or a group of formula (5) and the other A moiety is methane or a group of formula (6):
• wherein p, q, r, s, t, u and v are each an integer from 0 to 3, such that p+q≦5, r+s≦4 and u+v≦3,
• wherein m is an integer from 0 to 3.

A resist composition for exposure to ultraviolet light having a wavelength of at least 300 nm, comprising:

• (A) 80 parts by weight of an alkali-insoluble or substantially insoluble polymer having acidic functional groups protected with acid labile groups, which polymer becomes alkali-soluble upon elimination of the acid-labile groups;
• (B) 0.5 to 15 parts by weight of a photoacid generator selected from the group consisting of oxime sulfonate compounds, onium salts, β-ketosulfone derivatives, diazomethane derivatives, disulfone derivatives, sulfonic acid ester derivatives and imidoyl sulfonate derivatives;
• and
• (C) 0.1 to 15 parts by weight of a 1,2-naphthoquinonediazidosulfonyl group-bearing compound, with the proviso that said naphthoquinonediazidosulfonyl group-bearing compound is not a trihydroxybenzophenone.