Silicon nitride thin film with low absorption deposited by high rate reactive pulse magnetron sputtering

To deposit silicon nitride thin film with low absorption and high refractive index by using a reactive pulse magnetron sputtering (R-PMS) machine, a dependence of the optical properties on Ar gas pressure, duty cycle, and target-substrate distance was investigated. Under optimized conditions, the film with the extinction coefficient k of 6.2x10-4 and refractive index n of 2.08 at the wavelength of 500nm was obtained. Auger Electron Spectroscopy (AES) analysis of the silicon nitride thin film showed that the ratio of Si:N was 1:1 and it was homogenous to the film depth. The LWPF (edge filter) composed of SiN and SiO2 showed good characteristics as filter.