Negative resist composition and resist pattern forming process

Patent metadata

Field	Value
Publication number	US-10120279-B2
Application number	US-201715666757-A
Country	US
Kind code	B2
Filing date	Aug 2, 2017
Priority date	Aug 5, 2016
Publication date	Nov 6, 2018
Grant date	Nov 6, 2018

Abstract

A negative resist composition comprising (A) a sulfonium compound of betaine type and (B) a polymer is provided. 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 innvention claimed is:

1. A negative resist composition comprising
(A) a sulfonium compound having the formula (A):

wherein R 1 , R 2 and R 3 are each independently a C 1 -C 20 straight, branched or cyclic monovalent hydrocarbon group which may contain a heteroatom, p and q are each independently an integer of 0 to 5, r is an integer of 0 to 4, in case of p=2 to 5, two adjoining groups R 1 may bond together to form a ring with the carbon atoms to which they are attached, in case of q=2 to 5, two adjoining groups R 2 may bond together to form a ring with the carbon atoms to which they are attached, and in case of r=2 to 4, two adjoining groups R 3 may bond together to form a ring with the carbon atoms to which they are attached, and
(B) a base polymer containing a polymer comprising recurring units having the formula (B1):

wherein R A is hydrogen, fluorine, methyl or trifluoromethyl, R 11 is each independently halogen, an optionally halogenated C 2 -C 8 straight, branched or cyclic acyloxy group, optionally halogenated C 1 -C 6 straight, branched or cyclic alkyl group, or optionally halogenated C 1 -C 6 straight, branched or cyclic alkoxy group, A 1 is a single bond or a C 1 -C 10 straight, branched or cyclic alkylene group in which an ether bond may intervene in a carbon-carbon bond, s is 0 or 1, w is an integer of 0 to 2, a is an integer in the range: 0≤a≤5+2w−b, and b is an integer of 1 to 3.

2. The negative resist composition of claim 1 wherein the polymer further comprises recurring units of at least one type selected from units having the formulae (B2), (B3), and (B4):

wherein R A is as defined above, R 12 and R 13 are each independently a hydroxyl group, halogen atom, acetoxy group, optionally halogenated C 2 -C 8 straight, branched or cyclic acyloxy group, optionally halogenated C 1 -C 8 straight, branched or cyclic alkyl group, optionally halogenated C 1 -C 8 straight, branched or cyclic alkoxy group, or optionally halogenated C 2 -C 8 straight, branched or cyclic alkylcarbonyloxy group, R 14 is an acetyl group, acetoxy group, C 1 -C 20 straight, branched or cyclic alkyl group, C 1 -C 20 straight, branched or cyclic alkoxy group, C 2 -C 20 straight, branched or cyclic acyloxy group, C 2 -C 20 straight, branched or cyclic alkoxyalkyl group, C 2 -C 20 alkylthioalkyl group, halogen atom, nitro group, cyano group, sulfinyl group, or sulfonyl group, A 2 is a single bond or C 1 -C 10 straight, branched or cyclic alkylene group in which an ether bond may intervene in a carbon-carbon bond, c and d are each independently an integer of 0 to 4, e is an integer of 0 to 5, x is an integer of 0 to 2, and t is 0 or 1.

3. The negative resist composition of claim 1 wherein the polymer further comprises recurring units having the formula (B5):

wherein R A is as defined above, A 3 is a single bond or C 1 -C 10 straight, branched or cyclic alkylene group in which an ether bond may intervene in a carbon-carbon bond, R 15 is each independently halogen, an optionally halogenated C 2 -C 8 straight, branched or cyclic acyloxy group, optionally halogenated C 1 -C 6 straight, branched or cyclic alkyl group, or optionally halogenated C 1 -C 6 straight, branched or cyclic alkoxy group, W is hydrogen, a C 1 -C 10 straight, branched or cyclic monovalent aliphatic hydrocarbon group in which an ether, carbonyl or carbonyloxy moiety may intervene in a carbon-carbon bond, or an optionally substituted monovalent aromatic group, Rx and Ry are each independently hydrogen, a C 1 -C 15 alkyl group which may be substituted with a hydroxy or alkoxy moiety, or an optionally substituted monovalent aromatic group, Rx and Ry may bond together to form a ring with the carbon atom to which they are attached, excluding that Rx and Ry are hydrogen at the same time, y is an integer of 0 to 2, u is 0 or 1, f is an integer in the range: 0≤f≤5+2y−g, and g is an integer of 1 to 3.

4. The negative resist composition of claim 3 wherein the polymer further comprises recurring units of at least one type selected from units having the formulae (a1), (a2), and (a3):

wherein R B is each independently hydrogen or methyl, Z 1 is a single bond, phenylene group, —O—Z 12 —, or —C(═O)—Z 11 —Z 12 —, Z 11 is —O— or —NH—, Z 12 is a C 1 -C 6 straight, branched or cyclic alkylene, C 2 -C 6 straight, branched or cyclic alkenylene or phenylene group, which may contain a carbonyl, ester, ether or hydroxy moiety, Z 2 is a single bond or —Z 21 —C(═O)—O—, Z 21 is a C 1 -C 20 straight, branched or cyclic divalent hydrocarbon group which may contain a heteroatom-containing moiety, Z 3 is a single bond, methylene, ethylene, phenylene, fluorinated phenylene, —O—Z 32 —, or —C(═O)—Z 31 —Z 32 —, Z 31 is —O— or —NH—, Z 32 is a C 1 -C 6 straight, branched or cyclic alkylene, C 2 -C 6 straight, branched or cyclic alkenylene or phenylene group, which may contain a carbonyl, ester, ether or hydroxy moiety, M − is a non-nucleophilic counter ion, R 21 , R 22 , R 23 , R 24 , R 25 , R 26 , R 27 , and R 28 are each independently a C 1 -C 20 straight, branched or cyclic monovalent hydrocarbon group which may contain a heteroatom-containing moiety, or R 21 and R 22 may bond together to form a ring with the sulfur atom to which they are attached, or any two of R 23 , R 24 and R 25 or any two of R 26 , R 27 and R 28 may bond together to form a ring with the sulfur atom to which they are attached.

5. The negative resist composition of claim 4 wherein the polymer comprises recurring units having the formula (B1-1), recurring units having the formula (B5-1), and recurring units having the formula (a2):

wherein R A , R B , Z 2 , R 23 , R 24 , R 25 , Rx, Ry, W, b, and g are as defined above.

6. The negative resist composition of claim 4 wherein the base polymer (B) further contains another polymer comprising recurring units having the formula (B1) and recurring units having the formula (B5), but free of recurring units having the formulae (a1), (a2), and (a3).

7. The negative resist composition of claim 1 , further comprising (C) a crosslinker.

8. The negative resist composition of claim 3 , which is free of a crosslinker.

9. The negative resist composition of claim 1 , further comprising (D) a polymer comprising recurring units having the formula (D1) and recurring units of at least one type selected from units having the formulae (D2), (D3), (D4) and (D5):

wherein R B is each independently hydrogen or methyl, R C is each independently hydrogen, fluorine, methyl or trifluoromethyl, R 41 is hydrogen or a C 1 -C 5 straight or branched monovalent hydrocarbon group in which a heteroatom may intervene in a carbon-carbon bond, R 42 is a C 1 -C 5 straight or branched monovalent hydrocarbon group in which a heteroatom may intervene in a carbon-carbon bond, R 43a , R 43b , R 45a and R 45b are each independently hydrogen or a C 1 -C 10 straight, branched or cyclic alkyl group, R 44 , R 46 , R 47 and R 48 are each indepe

Assignees

• Shinetsu Chemical Co

Inventors

• Masunaga Keiichi
• Watanabe Satoshi
• Kotake Masaaki
• Yamada Kenji
• Ohashi Masaki

Classifications

• C08F220/283

  and containing one or more carboxylic moiety in the chain, e.g. acetoacetoxyethyl(meth)acrylate · CPC title

• C08F220/303

  and one or more carboxylic moieties in the chain · CPC title

• C08F220/382

  and containing oxygen, e.g. 2-sulfoethyl (meth)acrylate · CPC title

• G03F7/0382 Primary

  the macromolecular compound being present in a chemically amplified negative photoresist composition · CPC title

• C08F228/02

  by a bond to sulfur · CPC title