Characterization of Silicon Nitride Films

Various "silicon nitride" films have been prepared from , N2, , and in an rf‐promoted glow discharge reaction. These films are described primarily through the use of infrared absorption. Aided by ultraviolet absorption, the inclusion of excess silicon or of oxygen in the films is readily followed. Changes in index of refraction, etch rates in HF acid, and electrical conductivity of the films are correlated with the optical absorption study. Comparisons of these films with those formed by pyrolysis or by reactive sputtering are made. Some reproducible physical properties of an amorphous film are stated.