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US 9,285,678 B2Granted
Sulfonium salt, resist composition and resist pattern forming process
AssigneeShin-Etsu Chemical Co., Ltd.
InventorsDaisuke Domon, Keiichi Masunaga, Masayoshi Sagehashi, Satoshi Watanabe
Life of this patent
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Abstract
A sulfonium salt of formula (1) is provided wherein A1 is a divalent hydrocarbon group, A2 is a divalent hydrocarbon group, A3 is hydrogen or a monovalent hydrocarbon group, B1 is an alkylene or arylene group, k is 0 or 1, R1, R2 and R3 are alkyl, alkenyl, oxoalkyl, aryl, aralkyl or aryloxoalkyl. A resist composition comprising the sulfonium salt as PAG exhibits a very high resolution when processed by EB and EUV lithography. A pattern with minimal LER is obtainable.
Claims11
A sulfonium salt having the general formula (1):
- wherein A1 is a straight, branched or cyclic, C1-C10 divalent hydrocarbon group which may be substituted with a heteroatom or separated by a heteroatom,
- A2 is a straight, branched or cyclic, C1-C10 divalent hydrocarbon group,
- A3 is selected from the group consisting of those having the following formulae:
- wherein the broken line denotes a valence bond,
- B1 is a Ci-Cio alkylene group or C6-C18 arylene group which may contain an ethereal oxygen atom,
- k is 0 or 1,
- R1, R2 and R3 are each independently a substituted or unsubstituted, straight or branched C1-C10 alkyl, alkenyl or oxoalkyl group, or a substituted or unsubstituted C6-C18 aryl, aralkyl or aryloxoalkyl group, or any two or more of R1, R2 and R3 may bond together to form a ring with the sulfur atom.
4 more elements
Dependencies are inferred from the claim text.