We designed a new chemical amplification resist for ArF and KrF excimer lithography. The resist comprises alicyclic the copolymer of adamantylmethacrylate and tert-butylmethacrylate, with triphenylsulfonium hexafluoroantimonate as a photo acid generator. This resist is highly transparent at KrF and ArF wavelengths because it has no aromatic and its dry etch resistance is comparable to that of a Novolac resist. The lithographic performance of this resist was evaluated using a KrF excimer laser stepper. A less than 0.5 micron line and space pattern profile was obtained with our resist.