Resist polymer, resist composition and patterning process

摘要

A polymer comprising recurring units of formulae (1), (2) and (3) increases a dissolution rate in an alkali developer under the action of an acid. R<1>, R<2 >and R<5 >are H or CH3, R<3 >and R<4 >are H or OH, and X is a tertiary exo-alkyl group having a bicyclo[2.2.1]heptane structure, represented by any of formulae (X-1) to (X-4): wherein R<6 >is a C1-C10 alkyl group. A resist composition comprising the inventive polymer has a sensitivity to high-energy radiation, improved resolution and minimized line edge roughness and lends itself to micropatterning with electron beams or deep UV for VLSI fabrication.