Polymers, resist compositions and patterning process, novel tetrahydrofuran compounds and their preparation

摘要

A polymer comprising recurring units of formula (1-1) or (1-2) wherein R1, R2, R3 and R4 are H or alkyl, or R1 and R2, and R3 and R4 taken together may form a ring with each pair being alkylene, and k is 0 or 1 and having a Mw of 1,000-500,000 is novel. A resist composition comprising the polymer as a base resin is sensitive to high-energy radiation, has excellent sensitivity, resolution, etching resistance, and minimized swell and lends itself to micropatterning with electron beams or deep-UV.