SiOxNy Films deposited with SiCl4 by remote plasma enhanced CVD

摘要

Silicon oxynitride films have been deposited withSiCl4 by remote-plasma enhanced chemical vapor deposition(PECVD) at a substrate temperature of 250℃. Differentmixtures of O2 and NH3 were used to obtain different oxynitridecompositions ranging from SiO2 to an stoichiometry close tothat of silicon nitride. Rutherford backscattering spectrometrywas used to determine the chemical composition of the SiOxNyfilms. The behavior of the IR absorption spectra as well as therefractive index measured by ellipsometry were used to estimatethe effect of the different deposition parameters. It was foundthat the IR spectra show a shift of the characteristic peakassociated with the stretching vibration mode of the Si-O-Sibonds towards lower wavenumbers as the relative concentrationof ammonia was increased with respect oxygen. No doublepeaks associated with silicon oxide and silicon nitride wereobserved, indicating the formation of an homogeneous alloy.The IR spectra did not show any presence of water or hydrogenrelated impurities in the film.