A comparison of structures and properties of SiNx and SiOx films prepared by PECVD

Abstract In this paper, amorphous silicon nitride (SiN x ) and silicon oxide (SiO x ) films were prepared by plasma-enhanced chemical vapor deposition (PECVD). The chemical structures and physical properties of the resulting materials were investigated and compared. Results reveal that SiO x films match better with Si substrate, whereas SiN x films exhibit larger refractive index, moderate optical band gap, and higher Young's modulus and film hardness. In overall, SiN x films are more suitable to serve as supporting and insulating materials for VO x -based infrared microbolometers. The difference in the physical properties is attributed to various bonding configurations for the resulting materials. Finally, several methods for evaluating the residual stresses in amorphous thin films were discussed.