Compositional study of Silicon Rich Oxide films.

A compositional study of silicon rich oxide (SRO) films obtained by low pressure chemical vapor deposition (LPCVD) and plasma enhanced chemical vapor deposition (PECVD) is presented. As deposited and annealed SRO films were characterized by mean Infrared (IR) and X-ray photoelectron spectroscopy (XPS) techniques. IR spectra from SRO obtained by PECVD showed absorption bands related to silicon-hydrogen bonds. However, for SRO-LPCVD, only vibration bands due to Si-O motion were observed. Moreover, XPS analysis demonstrated that SRO-PECVD films contain a higher nitrogen concentration than the LPCVD ones. All the SRO films were subjected to thermal annealing in order to investigate the changes in the composition of the films. The hydrogen and nitrogen have shown being an important parameter to influence the optical properties of these films