To provide a new copolymer which has high transparency and high dry etching durability at 193 nm wavelength, and excellent solubility with an organic solvent, particularly solubility with a rinsing thinner used in the manufacture process of a semiconductor devices and which is more suitable as a resist resin for ArF excimer laser lithography.
The copolymer is a ternary copolymer obtained by radical polymerization of three kinds of monomers. The monomers used are a monomer having an alicyclic skeleton as a first monomer, a monomer having a lactone skeleton as a second monomer, and a vinyl monomer as a third polymer having such properties that the distribution coefficient of water/octanol is 1 and that the single polymer of the monomer shows ≤30°C polymer Tg.
KUWANO HIDEAKI
WAKIZAKA YUKIYA
