Sulfonium salt, chemically amplified resist composition, and pattern forming process
AssigneeShin-Etsu Chemical Co., Ltd.
InventorsMasaki Ohashi, Masahiro Fukushima, Tomohiro Kobayashi, Ryosuke Taniguchi
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Abstract
A caboxylic acid sulfonium salt having formula (1) is provided wherein R0 is hydrogen or a monovalent hydrocarbon group, R01 and R02 are hydrogen or a monovalent hydrocarbon group, at least one of R0, R01 and R02 has a cyclic structure, L is a single bond or forms an ester, sulfonate, carbonate or carbamate bond with the vicinal oxygen atom, R2, R3 and R4 are monovalent hydrocarbon groups. The sulfonium salt functions as a quencher in a resist composition, enabling to form a pattern of good profile with minimal LWR, rectangularity, and high resolution.
Claims17
A sulfonium salt having the general formula (1):
- wherein R0 is hydrogen, or a straight C1-C20 or branched or cyclic C3-C20 monovalent hydrocarbon group which may be substituted with or separated by a heteroatom,
- R01 and R02 are each independently hydrogen, or a straight C1-C20 or branched or cyclic C3-C20 monovalent hydrocarbon group which may be substituted with or separated by a heteroatom, or R01 and R02 may bond together to form a ring with the carbon atom to which they are attached, with the proviso that at least one of R0, R01 and R02 has a cyclic structure,
- L is a single bond or forms an ester bond, sulfonate bond, carbonate bond or carbamate bond with the vicinal oxygen atom,
- R2, R3 and R4 are each independently a straight C1-C20 or branched or cyclic C3-C20 monovalent hydrocarbon group which may be substituted with or separated by a heteroatom, at least two of R2, R3 and R4 may bond together to form a ring with the sulfur atom in the formula.
Dependencies are inferred from the claim text.