Fabrication and characterization of PECVD phosphorus-doped silicon oxynitride layers for integrated optics applications

摘要

Phosphorus-doped silicon oxynitride layers (n = 1.48 – 1.59) have been deposited by a Plasma Enhanced Chemical Vapor Deposition (PECVD) process from 2% SiH4/N2, N2O, NH3 and PH3 gaseous mixtures. The refractive indices of the deposited layers were found to increase by adding PH3 gas to the process. A slight variation in refractive index was observed in low refractive indices layers due to moisture absorption. Fourier transform infrared spectroscopy showed a significant reduction (40% –100%) in N-H bonds concentration for the P-doped silicon oxynitride, as compared with that for the undoped samples. These results are very promising for applications in low-loss integrated optical devices.