Design, preparation and characterization of antireflective coatings using oxynitride films

In present paper, we introduce an investigation of aluminum oxynitride films deposition using one metallic target in various gas mixture. The optimized preparation conditions for such reactive sputtering were found. Non-optimized conditions led to sputtering target poisoning or under-stoichiometric films formation. The reactive deposition process was guided by the active feedback control system. Dependence between gas composition and changes of nitrogen concentration in the films and their optical properties were investigated. The increase of nitrogen content in films leads to increases in extinction coefficient in UV region and refractive index in the whole investigated wavelength range. It was shown the possibility of using oxynitride films for antireflective coating (AR) deposition. The coating composed from three layer of oxynitrides with changing the composition. It has low surface roughness and low compressive stress.