POLYMER, POSITIVE RESIST COMPOSITION AND METHOD FOR FORMING RESIST PATTERN

摘要

Disclosed is a polymer which enables to form a resist pattern having high resolution and excellent etching resistance. Also disclosed are a positive resist composition and a method for forming a resist pattern. Specifically disclosed are a polymer having a constitutional unit (a1) represented by the general formula (a-1) below and a constitutional unit (a2) represented by the general formula (a-2) below, another polymer having the constitutional unit (a1) and a constitutional unit (a3) represented by the general formula (a-3) below, and a still another polymer having the constitutional unit (a1), the constitutional unit (a2) and the constitutional unit (a3). (a-1) (a-2) (a-3)