Synthesis and Characterization of Amorphous Si ₂ N ₂ O

Abstract

Amorphous silicon oxynitride powder was synthesized by nitridation of high‐purity silica in ammonia at 1120°C. The resulting material was X‐ray amorphous, and its chemical characteristics were determined by X‐ray photoelectron spectroscopy (XPS) and 29 Si nuclear magnetic resonance (NMR). The XPS analysis showed a shift to lower binding energies for the Si 2 p peak with increasing nitrogen content. Upon initial nitridation, the full width at half maximum (FWHM) of the Si 2 p peak increased, but decreased again at higher nitrogen contents, thus showing the formation of a silicon oxynitride phase with a single or small range of composition. The 29 Si NMR analysis showed the formation of (amorphous) Si 3 N 4 (Si–N 4 ) and possibly two oxynitride phases (Si–N 3 O, Si–N 2 O 2 ). It is concluded that while XPS, FT‐IR, and nitrogen analysis may show the formation of an homogeneous, amorphous silicon oxynitride (Si 2 N 2 O) phase, the formation of phase–pure, amorphous Si 2 N 2 O is extremely difficult via this route.