Sulfonium salt, polymer, resist composition, and patterning process
AssigneeShin-Etsu Chemical Co., Ltd.
InventorsMasahiro Fukushima, Jun Hatakeyama, Masaki Ohashi, Teppei Adachi
Life of this patent
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Abstract
A sulfonium salt having formula (1a) is provided wherein R1 is H, F, CH3 or CF3, R1a to R1m are each independently H or a monovalent hydrocarbon group, L is a single bond or divalent hydrocarbon group, X is a divalent alkylene group optionally substituted with fluorine, and n is 0 or 1. The sulfonium salt having a polymerizable anion provides for efficient scission of acid labile groups in a chemically amplified resist composition, and it is a very useful monomer from which a base resin for resist use is prepared.
Claims15
A sulfonium salt having the general formula (1a):
- wherein R1 is hydrogen, fluorine, methyl or trifluoromethyl, R1a to R1m are each independently hydrogen or a C1-C20 straight, branched or cyclic, monovalent hydrocarbon group which may be substituted with or separated by a heteroatom, L is a single bond or a C1-C20 straight, branched or cyclic, divalent hydrocarbon group which may be substituted with or separated by a heteroatom, X is a C1-C5 divalent alkylene group in which some or all hydrogen atoms may be substituted by fluorine atoms, and n is 0 or 1.
A polymer comprising recurring units having the general formula (2a):
- wherein R1 is hydrogen, fluorine, methyl or trifluoromethyl, R1a to R1m are each independently hydrogen or a C1-C20 straight, branched or cyclic, monovalent hydrocarbon group which may be substituted with or separated by a heteroatom, L is a single bond or a C1-C20 straight, branched or cyclic, divalent hydrocarbon group which may be substituted with or separated by a heteroatom, X is a C1-C5 divalent alkylene group in which some or all hydrogen atoms may be substituted by fluorine atoms, and n is 0 or 1.
Dependencies are inferred from the claim text.