Large area plasma enhanced chemical vapor deposition of nonstoichiometric silicon nitride

This paper presents results on PECVD of low refractive index silicon nitride in a large area system. Film deposition characteristics, such as deposition rate and thickness uniformity, were investigated over a wide range of process parameters, such as gas composition, power, pressure, and N2 pressure. Film properties, such as RI, absorbance, stress, and etch rate, have also been studied. A general model, which includes both the deposition and etching mechanisms, has been developed to explain these results. This model could explain the film uniformity issue in the process.