PROCESS-PARAMETER OPTIMIZATION OF SB2O3 FILMS IN THE ULTRAVIOLET AND VISIBLE REGION FOR INTERFEROMETRIC APPLICATIONS

The influence of different evaporation process parameters on the optic al properties and constants of thin Sb2O3 films in the ultraviolet and visible region from 250 to 800 nm has been investigated. The most dom inant parameters, namely the substrate temperature, rate of evaporatio n, and ambient oxygen pressure used during the deposition process and the post-annealing temperatures were optimised which resulted in low l oss, dense and homogeneous Sb2O3 films. The optical constants and band gaps of these films were evaluated using their interference modulated transmittance spectra in case of both homogeneous and inhomogeneous c onditions. Optimized films have been successfully used in developing m ultilayer high reflecting coatings for Fabry-Perot etalons along with the cryolite (Na3AlF6) films.