Properties of Si3N4and AIN Films Produced by Reactive Ion Plating and Gas Discharge Sputtering

Abstract
Thin films of Silicon‐ and Aluminiumnitride were produced by Reactive Low Voltage Ion Plating and low pressure dc‐Magnetron Sputtering. The films show excellent adherence, high hardness and abrasion resistance, and are dense and homogeneous. Both processes, applied at optimum conditions, enable the production of films with nearly identical optical properties. Such optimized deposition conditions in both processes yielded a mean refractive index of n550= 2.05 ± 0.03 for Si3N4and of n550= 2.12 ± 0.01 for AIN films. The region of high optical transmission was found to be between 0.23 and 9.5μm (Si3N4) and between 0.2 and 12.5 μm (AIN). In the visible range both metal nitride films are free of optical absorption (k −3). These materials, together with their oxynitride phases, offer interesting applications for the deposition of optical multilayer systems with very high spectral stability.