OPTICAL-PROPERTIES AND STRUCTURE OF THERMALLY EVAPORATED TIN OXIDE-FILMS

Tin oxide films have been grown by thermal evaporation of SnO2 powder from a resistively heated alumina crucible. Analysis by X-ray diffraction and Rutherford backscattering spectrometry has shown that the films are of an amorphous nature, with a typical stoichiometry of SnO1.3. Detailed optical measurements have shown that the films have a refractive index close to two and a negligible extinction coefficient over the 2-10 mum wavelength range. Such films appear to be well suited to the fabrication of simple, single layer anti-reflection coatings for use on both germanium and silicon in the infrared.