Sol-gel derived silica and titania doped silica films were fabricated by spin coating on silicon substrates. The work primarily deals with the influence of various sol-gel processing parameters such as addition of base catalyst, water to precursor ratio and sol pH on the gel times and consequently on the film thickness. The viscosity of the sol increases gradually with time and then attains a large value very rapidly for a given amount of base catalyst. Increase in the amount of base catalyst increase the gel time. As the molar ratio of water to precursor is increased the gel time initially decreases, however at large values of the ratio the gel time increase and the resulting films are thinner. Titania doped silica films were also fabricated. The thickness of silica films doped with 5.25 mol% titania decreases with spin speed.