The deprotection and dissolution reactions for the ArF chemically amplified resist, consisting of a new alicyclic terpolymer with tricyclodecanyl groups and new afkylsulfonium salts are analyzed quantitatively. The deprotection of the tetrahydropyranyl groups is analyzed by Fourier transform infrared measurement, and this analysis shows that the order of acid reaction (1.4) and acid lifetime (1000 s) are the same as in other KrF resist systems. Furthermore, this analysis of dissolution behavior demonstrated that the new polymer has a dissolution rate ratio more than 1000 and a slope similar to that of the conventional novolac resist. These characteristics indicate that the performance of this new terpolymer system is satisfactory for use in lithography.