Formation of silicon oxide thin films from spin-coated β-chloroethyl silsesquioxane (β-cesq) on silicon, NaCl, and quartz was induced by 193 nm laser pulses. The silicon oxide deposition is characterized by ir, uv, ellipsometry, and Rutherford backscattering spectrometry. The silicon oxide films obtained by uv irradiation were found to have much less carbon and chlorine as impurities and have a higher refractive index as compared to those obtained by annealing. The photoinduced oxide films were found to be smooth, without laser-induced microrough or periodic structures.