POSITIVE RESIST COMPOSITION AND METHOD OF FORMATION OF RESIST PATTERNS

摘要

The invention provides a positive resist composition which has high etching resistance and attains high resolution and a method of forming patterns by using the resist composition. The positive resist composition contains a resin component (A) which has acid-dissociable dissolution-inhibiting groups and can be enhanced in the solubility in alkali by the action of an acid and an acid generator component (B) which generates an acid upon exposure, the resin component (A) being a polymer comprising structural units (a1) represented by the general formula (I) and part of the hydroxyl groups of the units (a1) being protected by replacing the hydrogen atoms by acid-dissociable dissolution-inhibiting groups represented by the general formula (II): wherein R is hydrogen or methyl; R<1> is alkyl having 1 to 5 carbon atoms; R<2> is alkyl having 1 to 5 carbon atoms or hydrogen; and X is an aliphatic polycyclic group having 10 to 16 carbon atoms or an aromatic polycyclic hydrocarbon group having 10 to 16 carbon atoms.