SULFONIUM SALT, CHEMICALLY AMPLIFIED RESIST COMPOSITION, AND PATTERNING PROCESS

摘要

A sulfonium salt having both anion and cation moieties in the molecule functions as a photoacid generator and is compatible with other components. A resist composition comprising the sulfonium salt has the advantages of reduced acid diffusion and forms a pattern with a good balance of sensitivity, MEF and DOF, less outgassing, and minimal defects.

主权项

1. A sulfonium salt having the formula (1):wherein R11 is a straight, branched or cyclic C1-C30 divalent hydrocarbon group which may contain a heteroatom, R12 and R13 are each independently a straight, branched or cyclic C1-C20 monovalent hydrocarbon group which may contain a heteroatom, any two or more of R11, R12 and R13 may bond together to form a ring with the sulfur atom to which they are attached, L1 is a carbonyl bond, sulfonyl bond or sulfinyl bond, L2 is a single bond, ether bond, carbonyl bond, ester bond, amide bond, sulfide bond, sulfinyl bond, sulfonyl bond, sulfonic acid ester bond, sulfinamide bond, sulfonamide bond, carbamate bond or carbonate bond, A1 is hydrogen, halogen or a straight, branched or cyclic C1-C20 monovalent hydrocarbon group which may contain a heteroatom, xa and Xb are each independently hydrogen, fluorine or trifluoromethyl, at least one of Xa and Xb is fluorine or trifluoromethyl, and k1 is an integer of 1 to 4.