SULFONIUM SALT MONOMER, POLYMER, CHEMICALLY AMPLIFIED RESIST COMPOSITION, AND PATTERN FORMING PROCESS

原文（中国語）

The sulfonium salt monomer is for a chemically amplified resist composition processed by photolithography using, in particular, high-energy radiation such as KrF excimer laser, ArF excimer laser, an electron beam (EB) or EUV, has excellent solvent solubility and a high sensitivity and contrast, and is excellent in lithographic performance such as exposure tolerance (EL), LWR, CDU and depth of focus (DOF), and excellent in resistance to pattern collapse and etch resistance even in fine pattern formation, a polymer comprising repeat units derived from the sulfonium salt monomer. The sulfonium salt monomer has the formula (a).