Techniques for physical and chemical evaluation of silicon oxide films formed by a wide variety of techniques have been developed. It has been established that by the use of infrared absorption spectroscopy, preferential etching procedures, precise optical measurements of thickness, density, and refractive indices, and carefully chosen environmental tests, differences in the oxide films can be determined. Techniques of oxidation studied were: thermal (oxygen and steam), evaporated, pyrolytic, lead catalyzed, sputtered and anodic. In many cases, improvement of oxide film properties can be achieved by simple thermal treatment of the original films.