Poly[(methacrylic acid tert-butyl cholate ester)-co-(γ-butyrolactone- 2-yl methacrylate)] was synthesized and evaluated as a new 193-nm chemically amplified photoresist. This polymer showed good thermal stability up to 240°C and had a good transmittance at 193 nm. This material showed good resistance to CF 4-reactive ion etching. The resist patterns of 0.15 μm feature size were obtained at a dose of 11mJcm -2 using an argon fluoride excimer laser stepper.