Methacrylate-based photoresist for ArF excimer laser lithography

A new positive chemically amplified resist which is terpolymer of methyl me thacrylate (MMA), methacrylic acid (MAA) and 1,3-bis(trimethylsilyl)isoprop yl methacrylate (BPMA) have been developed for ArF excimer laser photoresis ts. Terpolymer is composed of a silicon containing acid labile protecting g roup which can be deprotected by photo acid generator (PAG). Terpolymer has good thermal stability up to 140 degrees C and it's UV transmittance for a 0.5 mu m thickness film was 78 To at 193 nm. Preliminary patterning result showed that the newly designed resist was capable of resolving 0.20 mu m f eatures.