The present invention provides chemically amplified silsesquioxane polymers for preparing masks using e-beam lithography. The silsesquioxane polymers have reactive sidechains that in the presence of an acid undergo acid catalyzed rearrangement to generate reactive functionalities that crosslink to form Si—O—Si bonds. The reactive side-chains comprise β- and γ-substituted alkyl groups bound to the silicon of the silsesquioxane polymer. The substituent of the β- and γ-substituted alkyl group is an electron withdrawing group. Resists generated with the chemically amplified silsesquioxane polymers of the present invention and imaged with e-beams have resolution of ≦60 nm line/space.