Polymers, resist compositions and patterning process

摘要

A polymer comprising units of formulas (1) and (2) and having a Mw of 1,000-500,000 is provided. R<1> is H, CH3 or CH2CO2R<3>. R<2> is H, CH3 or CO2R<3>, R<3> is alkyl, R<4> is halogen or acyloxy, alkoxycarbonyloxy or alkylsulfonyloxy group which may be substituted with halogen, R<5> is H or alkyl, R<6> is an acid labile group, Z is a single bond or a divalent hydrocarbon group, k is 0 or 1, and W is -O- or -(NR)- wherein R is H or alkyl. A resist composition comprising the polymer as a base resin is sensitive to high-energy radiation, has excellent sensitivity, resolution, and etching resistance, and lends itself to micropatterning with electron beams or deep-UV rays.