Chemically amplified positive photoresist composition and pattern forming process

摘要

A polymer comprising a high proportion of aromatic ring structure-containing units and containing an aromatic sulfonic acid sulfonium salt on a side chain is used to form a chemically amplified positive photoresist composition which is effective in forming a resist pattern having high etch resistance. The polymer overcomes the problems of dissolution in solvents for polymerization and purification and in resist solvents.