Chemically amplified positive resist composition and resist pattern forming process

Patent metadata

Field	Value
Publication number	US-10495969-B2
Application number	US-201715854244-A
Country	US
Kind code	B2
Filing date	Dec 26, 2017
Priority date	Dec 28, 2016
Publication date	Dec 3, 2019
Grant date	Dec 3, 2019

Abstract

A positive resist composition comprising a polymer adapted to be decomposed under the action of acid to increase its solubility in alkaline developer and a sulfonium compound of formula (A) has a high resolution. When the resist composition is processed by lithography, a pattern with minimal LER can be formed.

First claim

The invention claimed is:

1. A positive resist composition comprising (A) a sulfonium compound having the formula (A) and (B) a base polymer containing a polymer comprising recurring units having the formula (B1), adapted to be decomposed under the action of acid to increase its solubility in alkaline developer,

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, 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,

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 C 1 -C 10 straight, branched or cyclic alkylene group in which an ether bond may intervene in a carbon-carbon bond, v is 0 or 1, w is an integer of 0 to 2, a is an integer satisfying 0≤a≤5+2w−b, and b is an integer of 1 to 3.

2. The positive resist composition of claim 1 wherein the polymer further comprises recurring units having the formula (B2):

wherein R A is as defined above, R 12 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 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, s is 0 or 1, t is an integer of 0 to 2, c is an integer satisfying: 0≤c≤5+2t−e, d is 0 or 1, e is an integer of 1 to 3, in case of e=1, X is an acid labile group, and in case of e=2 or 3, X is hydrogen or an acid labile group, at least one X being an acid labile group.

3. The positive resist composition of claim 1 wherein the polymer further comprises recurring units of at least one type selected from units having the formulae (B3), (B4), and (B5):

wherein R A is as defined above, R 13 and R 14 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 15 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 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, f and g are each independently an integer of 0 to 4, b is 0 or 1, j is an integer of 0 to 5, and k is an integer of 0 to 2.

4. The positive resist composition of claim 1 wherein the polymer further comprises recurring units of at least one type selected from units having the formulae (B6) to (B13):

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, Z 4 is a single bond or a C 1 -C 30 straight, branched or cyclic divalent hydrocarbon group which may contain a heteroatom, u is 0 or 1, with the proviso that u is 0 when Z 4 is a single bond, R 21 to R 38 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 , any two of R 26 , R 27 and R 28 or any two of R 29 , R 30 and R 31 may bond together to form a ring with the sulfur atom to which they are attached, A is hydrogen or trifluoromethyl, and M − is a non-nucleophilic counter ion.

5. The positive resist composition of claim 1 , further comprising (C) a fluorinated polymer comprising recurring units having the formula (C1) and recurring units of at least one type selected from units having the formulae (C2), (C3), (C4), and (C5):

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 independently hydrogen, a C 1 -C 15 straight, branched or cyclic monovalent hydrocarbon group or monovalent fluorinated hydrocarbon group, or an acid labile group, with the proviso that an ether or carbonyl moiety may intervene in a carbon-carbon bond in the monovalent hydrocarbon groups or monovalent fluorinated hydrocarbon groups represented by R 44 , R 46 , R 47 and R 48 , x is an integer of 1 to 3, y is an integer satisfying: 0≤y≤5+2z−x, z is 0 or 1, m is an integer of 1 to 3, X 1 is a single bond, —C(═O)—O— or —C(═O)—NH—, and X 2 is a C 1 -C 20 straight, branched or cyclic (m+1)-valent hydrocarbon group or fluorinated hydrocarbon group.

6. The positive resist composition of claim 1 , further comprising (D) an organic solvent.

7. The positive resist composition of claim 1 , further comprising (E) a photoacid generator.

8. A resist pattern forming process comprising the

Assignees

• Shinetsu Chemical Co

Inventors

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

Classifications

• G03F7/2059

  using a scanning corpuscular radiation beam, e.g. an electron beam · CPC title

• G03F7/322

  Aqueous alkaline compositions · CPC title

• G03F7/0395

  the macromolecular compound having a backbone with alicyclic moieties · CPC title

• G03F7/0045 Primary

  with organic non-macromolecular light-sensitive compounds not otherwise provided for, e.g. dissolution inhibitors · CPC title

• G03F7/0397

  the macromolecular compound having an alicyclic moiety in a side chain · CPC title