Abstract: A chemically amplified positive resist composition comprising a styrene polymer represented by formula (1), terminated with P, and having a weight average molecular wherein R is OH or OR3, R1 is H or CH3, R2 is alkyl, R3 is acid labile group, x≧0, y>0, k≧0, m≧0, n>0, 0<q≦0.8, p+q=1, P is H, alkyl, alkenyl, aromatic, carboxyl, OH, —R4(COR5)r, —R4O(OH)r or —R4 (OR5)r. A chemically amplified positive resist composition comprising the polymer as a base resin has high sensitivity and resolution and forms resist patterns having plasma etching resistance, heat resistance, and reproducibility.

Abstract: A styrene polymer represented by formula (1), terminated with P, and having a weight average molecular 1

Abstract: A styrene polymer represented by formula (1), terminated with P, and having a weight average molecular wherein R is OH or OR3 R1 is H or CH3, R2 is alkyl, R3 is acid labile group, x≧0, y>0, k≧0, m≧0, n>0, 0<q≦0.8, p+q=1, P is H, alkyl, alkenyl, aromatic, carboxyl, OH, —R4 (COR5)r, —R4O (OH)r or —R4 (OR5)r. A chemically amplified positive resist composition comprising the polymer as a base resin has high sensitivity and resolution and forms resist patterns having plasma etching resistance, heat resistance, and reproducibility.

Abstract: A resist composition comprising (A) an organic solvent; (B) at least two polymers with weight average molecular weights of 1,000-500,000, which have at least one type of acid labile group and are crosslinked within a molecule and/or between molecules with crosslinking groups having C--O--C linkages; and (C) a photoacid generator is sensitive to high-energy radiation, has excellent sensitivity, resolution, and plasma etching resistance, and provides resist patterns of outstanding thermal stability and reproducibility. Patterns obtained with this resist composition are less prone to overhanging and have excellent dimensional controllability. The resist composition is suitable as a micropatterning material for VLSI fabrication because it has a low absorption at the exposure wavelength of a KrF excimer laser, thus enabling the easy formation of a finely defined pattern having sidewalls perpendicular to the substrate.