| 摘要 |
PROBLEM TO BE SOLVED: To obtain a new sulfonium salt useful as a component for chemical amplification positive type resist materials suitable for fine processing techniques. SOLUTION: This compound is expressed by formula I [R<1> , R<2> , R<3> are each an aromatic group; at least one of R<1> -R<3> is a substituted aromatic group having an acid-unstable group, and at least one of the others is a nitrogen atom- containing aromatic group; or all of R<1> -R<3> are each a nitrogen atom-containing aromatic group; Z is H, an alkyl, an alkoxy; (n) is 1-5], e.g. p-toluene sulfonic acid tris(4-dimethylaminophenyl) sulfonium salt. The compound of formula I is obtained by reacting a substituted diarylsulfoxide of formula II with a trialkylsilyl arylsulfonate of formula III(R<4> is an alkyl) and further reacting the reaction product with a Grignard reagent. The compound of formula I can reduce the inactivation actions of basic compounds not only on the surfaces of resist films but also on the interfaces between the resist films and substrates, improve pattern profile shapes, and enlarge dissolution contrasts between exposed parts and unexposed parts, when having an acid-unstable group. |
