Chemically amplified negative resist composition using novel onium salt and resist pattern forming process

Patent metadata

Field	Value
Publication number	US-9740098-B2
Application number	US-201615094348-A
Country	US
Kind code	B2
Filing date	Apr 8, 2016
Priority date	Apr 13, 2015
Publication date	Aug 22, 2017
Grant date	Aug 22, 2017

Abstract

A chemically amplified negative resist composition is defined as comprising (A) an onium salt having an anion moiety which is a nitrogen-containing carboxylate of fused ring structure, (B) a base resin, and (C) a crosslinker. The resist composition is effective for controlling acid diffusion during the exposure step, exhibits a very high resolution during pattern formation, and forms a pattern with minimal LER.

First claim

The invention claimed is:

1. A chemically amplified negative resist composition comprising
(A) an onium salt having the formula (1) or (2),
(B) a resin (U-1) comprising recurring units having the formula (3), and
(C) a crosslinker,

wherein R 01 , R 02 , R 03 and R 04 are each independently hydrogen, -L-CO 2 − , or a straight C 1 -C 20 , branched or cyclic C 3 -C 20 monovalent hydrocarbon group which may be substituted with or separated by a heteroatom, or a pair of R 01 and R 02 , R 02 and R 03 , or R 03 and R 04 may bond together to form a ring with the carbon atoms to which they are attached, L is a single bond or a straight C 1 -C 20 , branched or cyclic C 3 -C 20 divalent hydrocarbon group which may be substituted with or separated by a heteroatom, R 05 is hydrogen or a straight C 1 -C 20 , branched or cyclic C 3 -C 20 monovalent hydrocarbon group which may be substituted with or separated by a heteroatom, R 06 , R 07 , R 08 , R 09 , R 010 and R 011 are each independently hydrogen or a straight C 1 -C 20 , branched or cyclic C 3 -C 20 monovalent hydrocarbon group which may be substituted with or separated by a heteroatom, or a pair of R 06 and R 07 may bond together to form a ring with the carbon atoms to which they are attached, a pair of R 08 and R 011 may bond together to form a ring with the carbon atoms to which they are attached and any intervening carbon atoms, or a pair of R 09 and R 010 may bond together to form a ring with the nitrogen atom, j is 0 or 1, k is a number in the range: 0≦k≦1 when j=0, or 0≦k≦3 when j=1, and Z + is a sulfonium cation of the formula (a) or an iodonium cation of the formula (b):

wherein R 100 , R 200 , and R 300 are each independently a straight C 1 -C 20 , branched or cyclic C 3 -C 20 monovalent hydrocarbon group which may be substituted with or separated by a heteroatom, or any two or more of R 100 , R 200 , and R 300 may bond together to form a ring with the sulfur atom, R 400 and R 500 are each independently a straight C 1 -C 20 , branched or cyclic C 3 -C 20 monovalent hydrocarbon group which may be substituted with or separated by a heteroatom,
the partial structure represented by the formula:

is a cyclic structure having the intervening nitrogen atom in which a hydrogen atom bonded to a cyclic structure-forming carbon atom may be replaced by a straight C 1 -C 20 , branched or cyclic C 3 -C 20 monovalent hydrocarbon group or -L-CO 2 − , or in which a cyclic structure-forming carbon atom may be replaced by sulfur, oxygen or nitrogen, with the proviso that one substituent: -L-CO 2 − is essentially included in formula (1),

wherein A is a single bond or a C 1 -C 10 alkylene group which may contain an ether bond at an intermediate of its chain, R 012 is hydrogen, fluorine, methyl or trifluoromethyl, R 013 is hydrogen, halogen, an optionally halo-substituted, straight, branched or cyclic C 2 -C 8 acyloxy group, an optionally halo-substituted, straight, branched or cyclic C 1 -C 6 alkyl group, or an optionally halo-substituted, straight, branched or cyclic C 1 -C 6 alkoxy group, b is an integer of 1 to 5, s is an integer of 0 to 2, a is an integer equal to or less than (5+2s−b), and p is 0 or 1.

2. The resist composition of claim 1 wherein the resin (B) further comprises recurring units of at least one type selected from units having the formulae (5), (6), and (7):

wherein B is a single bond or a C 1 -C 10 alkylene group which may contain an ether bond at an intermediate of its chain, R 012 is hydrogen, fluorine, methyl or trifluoromethyl, R 015 and R 016 are each independently hydrogen, an optionally halo-substituted C 1 -C 6 alkyl group or primary or secondary alkoxy group, or an optionally halo-substituted C 2 -C 7 alkylcarbonyloxy group, R 017 is hydrogen, a straight, branched or cyclic C 1 -C 20 alkyl, alkoxy or acyloxy group, C 2 -C 20 alkoxyalkyl group, C 2 -C 20 alkylthioalkyl group, halogen, nitro, cyano, sulfinyl, or sulfonyl group, c and d each are an integer of 0 to 4, e is an integer of 0 to 5, f is an integer of 0 to 2, and q is 0 or 1.

3. The resist composition of claim 1 , further comprising an acid generator capable of generating an acid upon exposure to high-energy radiation.

4. The resist composition of claim 1 , further comprising (D) a polymer comprising recurring units having the formula (8) and fluorine-containing recurring units of at least one type selected from the formulae (9), (10), (11) and (12):

wherein R 50 is hydrogen or methyl, R 51 is hydrogen or a straight or branched C 1 -C 5 monovalent hydrocarbon group which may be separated by a heteroatom, R 52 is a straight or branched C 1 -C 5 monovalent hydrocarbon group which may be separated by a heteroatom, R 53 is hydrogen, fluorine, methyl or trifluoromethyl, R 53a and R 53b are each independently hydrogen or a straight, branched or cyclic C 1 -C 10 alkyl group, R 54 is each independently hydrogen, a straight, branched or cyclic C 1 -C 15 monovalent hydrocarbon or fluorinated hydrocarbon group, or an acid labile group, with the proviso that in the monovalent hydrocarbon or fluorinated hydrocarbon group represented by R 54 , an ether bond (—O—) or carbonyl moiety (—C(═O)—) may intervene in a carbon-carbon bond, α is an integer of 1 to 3, β is an integer satisfying 0≦β≦5+2γ−α, γ is 0 or 1, δ is an integer of 1 to 3, X 1 is a single bond, —C(═O)O— or —C(═O)NH—, E is a straight, branched or cyclic C 1 -C 20 (δ+1)-valent hydrocarbon or fluorinated hydrocarbon group.

5. A photomask blank coated with the chemically amplified negative resist composition of claim 1 .

6. A pattern forming process comprising the steps of:
applying the chemically amplified negative resist composition of claim 1 onto a processable substrate to form a resist film thereon,
exposing the resist film patternwise to high-energy radiation, and
developing the resist film in an alkaline developer to form a resist pattern.

7. The process of claim 6 wherein the high-energy radiation is EUV or EB.

8. The process of claim 6 wherein the processable substrate is a photomask blank.

9. A chemically amplified negative resist composition comprising
(A) an onium salt having the formula (1) or (2), and
(B) a resin (U-2) adapted to turn alkali insoluble under the action of acid, the resin comprising recurring units having the formulae (3) and (4),

wherein R 01 , R 02 , R 03 and R 04 are each independently hydrogen, -L-CO 2 − , or a straight C 1 -C 20 , branched or cyclic C 3 -C 20 monovalent hydrocarbon group which may be substituted with or separated by a heteroatom, or a pair of R 01 and R 02 , R 02 and R 03 , or R 03 and R 04 may bond together to form a ring with the carbon atoms to which they are attached, L is a single bond or a straight C 1 -C 20 , branched or cyclic C 3 -C 20 divalent hydrocarbon group which may be substituted with or separated by a heteroatom, R 05 is hydrogen or a straight C 1 -C 20 , branched or cyclic C 3 -C

Assignees

• Shinetsu Chemical Co

Inventors

• Masunaga Keiichi
• Watanabe Satoshi
• Kotake Masaaki
• Domon Daisuke
• Fujiwara Takayuki

Classifications

• G03F7/004

  Photosensitive materials (G03F7/12, G03F7/14 take precedence) · CPC title

• G03F7/322

  Aqueous alkaline compositions · CPC title

• G03F7/09

  characterised by structural details, e.g. supports, auxiliary layers (supports for printing plates in general B41N) · CPC title

• C07C211/62

  Quaternary ammonium compounds · CPC title

• G03F1/66

  Containers specially adapted for masks, mask blanks or pellicles; Preparation thereof · CPC title