Oxides of Ti, Zr, Si and Al were deposited by ion beam sputter deposition with a Kaufman-type ion source. The deposition rate, refractive index, extinction coefficient, and surface roughness of the oxide films are influenced by the partial pressure of oxygen. The surface morphology measured by an atomic force microscope shows that there is a certain range of optimum oxygen partial pressure which yields a smooth him of good optical quality. Baking makes the film surface rougher if the baking temperature is too high. The amount of oxygen supplied during the deposition can also influence the baking effect. Comparisons and explanations with existing literature are attempted.