Stability of SiN_x Prepared by Plasma-Enhanced Chemical Vapor Deposition at Low Temperature

In this paper, the environmental stability of silicon nitride (SiNx) films deposited at 80 °C by plasma-enhanced chemical vapor deposition was studied systematically. X-ray photoelectron spectroscopy and Fourier transform infrared reflection were used to analyze the element content and atomic bond structure of the amorphous SiN_x films. Variation of mechanical and optical properties were also evaluated. It is found that SiN_x deposited at low temperature is easily oxidized, especially at elevated temperature and moisture. The hardness and elastic modulus did not change significantly with the increase of oxidation. The changes of the surface morphology, transmittance, and fracture extensibility are negligible. Finally, it is determined that SiN_x films deposited at low-temperature with proper processing parameters are suitable for thin-film encapsulation of flexible devices.