Patent ID: 7300741

Claim:
A chemically amplified resist composition for printing features having a dimension of about 30 nm or less comprising (a) about 1 to about 50 weight % of a copolymer having a dissolution rate of about 100 nm per second or less in 0.263N tetramethyl ammonium hydroxide (TMAH) developer, (b) about 0.02 to about 25 weight % of a photoacid generator, (c) about 47 to about 99 weight % of a solvent, and (d) about 0.004 to about 25 weight % of a base additive; said copolymer comprising at least one hydrophilic monomer unit containing one or more polar functional groups and at least one hydrophobic monomer unit containing one or more aromatic groups, wherein some, but not all, of said one or more polar functional groups are protected with acid labile moieties having a low activation energy.