Disclosed herein is a polyhydroxy ketal adduct obtained by the esterification of a hydrocarbon polyol by at least 1.5 equivalents of a ketocarboxy to produce an intermediate ketocarboxylic ester. The intermediate polyketocarboxylic ester is then ketalized to produce the polyhydroxyketal adduct, which can be used to provide a polymeric composition.

Disclosed herein is a polyhydroxy ketal adduct obtained by the esterification of a hydrocarbon polyol by at least 1.5 equivalents of a ketocarboxy to produce an intermediate ketocarboxylic ester. The intermediate polyketocarboxylic ester is then ketalized to produce the polyhydroxyketal adduct, which can be used to provide a polymeric composition.

A positive resist composition based on a polymer comprising recurring units (a) of (meth)acrylate having an iodized lactone ring, and recurring units (b1) having a carboxyl group substituted with an acid labile group and/or recurring units (b2) having a phenolic hydroxyl group substituted with an acid labile group has a high sensitivity and resolution, and forms a pattern of good profile and minimal edge roughness after exposure.

A positive resist composition based on a polymer comprising recurring units (a) of (meth)acrylate having an iodized lactone ring, and recurring units (b1) having a carboxyl group substituted with an acid labile group and/or recurring units (b2) having a phenolic hydroxyl group substituted with an acid labile group has a high sensitivity and resolution, and forms a pattern of good profile and minimal edge roughness after exposure.

A positive resist composition based on a polymer comprising recurring units (a) of (meth)acrylate having an iodized lactone ring, and recurring units (b1) having a carboxyl group substituted with an acid labile group and/or recurring units (b2) having a phenolic hydroxyl group substituted with an acid labile group has a high sensitivity and resolution, and forms a pattern of good profile and minimal edge roughness after exposure.