S1-H BONDING ENVIRONMENT IN PECVD A-SIOXNY-H THIN-FILMS

We constructed silicon oxynitride thin films of various compositions b y Plasma Enhanced Chemical Vapor Deposition and studied the global str ucture by infrared absorption. The Si-H band frequency is related to t he environment of Si atom. We considered the Si-H band as the sum of s everal gaussian curves corresponding to the different silicon-centered tetraedra present in the material. The frequency of Si-H bond for eac h tetrahedron was calculated using Lucovsky linear relations and then the tetrahedra were attributed to gaussians found by decomposition of the band. The results show the presence of tetrahedra with both N and O atoms bound to silicon. These tetrahedra cannot agree with a model o f phase separation, however the Random Bonding Model envisages the exi stence of these environments. So we consider our silicon oxynitride fi lms to be a homogeneous statistical mixture of the various bonds rathe r than a mixture of phases. Published by Elsevier Science Limited.