Optical coatings may be deposited from clear polymeric solutions derived from metal-organic compounds. These coatings are converted to their oxide counterparts upon heating at temperatures of 400–500°C. In this work, the surface roughness of solution deposited SiO2 films were investigated in order to assess their suitability for such applications as waveguides, mirrors, etc.
SiO2 films deposited from polymeric siloxane solutions show rms surface roughness as low as 2.2Å in profile scans extending over 600 μm. The surface roughness of these films, as well as other properties, are found to be modified by the deposition method, e.g., spin or dip coating, as well as by the reaction parameters involved in the solution preparation.