Lithographic Properties of Poly(tert-butyl methacrylate)-Based Block and Random Copolymer Resists Designed for 193 nm Wavelength Exposure Tools

Block and random copolymers were prepared using the monomers tert -butyl methacrylate and [3-(methacryloxy)propyl]pentamethyldisiloxane. The polymers have low absorption at 193 nm wavelength, making them attractive candidates for 193 nm wavelength imaging. The resists have a high resistance to oxygen reactive ion etching, making them suitable for the imagable layer of a bilevel resist system. After exposure, the block copolymers have better development behavior in aqueous base than that of the corresponding random copolymers even though they have a long hydrophobic siloxane block.