XPS and FTIR study of silicon oxynitride thin films

SiNx, SiOx and SiOxHy deposits containing various hydrogen concentrations were prepared in a plasma enhanced chemical vapour deposition (PECVD) reactor using SiH4, NH3 and N2O as precursor gases. These deposits were made for anti-reflection coatings on polymer substracts. In this work, we present a study of the compositions and the chemical environments of silicon, oxygen and nitrogen in these films by using XPS, XAES and FTIR characterization methods. It is shown that the SiO,N, deposits are constituted by various silicon environments which can be described by the presence of Si(OxNyHz) tetrahedra with x+y+z=4. The amount of Si-H bonds increases in the deposits when the nitrogen concentration increases. Si-OH chemical bonds were detected for low nitrogen concentration. Published by Elsevier Science Limited.