Structural differences between deuterated and hydrogenated silicon nitride/oxynitride

Hydrogenated and deuterated silicon nitride (a-SiNx:H and a-SiNx:D) and sil icon oxynitride (a-SiOxNy:H and a-SiOxNy:D) films are prepared by plasma-en hanced chemical vapor deposition. Their transmission and photoluminescence spectra were measured. Both the photoluminescence and transmission spectra show that the deuterated films have higher energy gaps than those of the hy drogenated films in the same growth condition. The infrared absorption spec tra of these samples are identified and compared in detail. From the infrar ed spectra, the interaction between N-D bond rocking vibration and Si-N bon d stretching vibration is observed, which pushes N-D bond rocking vibration to a higher energy. It is also observed that the refractive index of deute rated film is lower than the hydrogenated film in the same growth condition due to its lower density. (C) 2001 American Institute of Physics.