The Conversion of Perhydropolysilazane into SiON Films Characterized by X-Ray Photoelectron Spectroscopy


  • Based in part on the dissertation submitted by Kaishi Wang for the PhD degree in Materials Science and Engineering, University of Washington, Seattle, WA 98195-2120, USA.

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Silicon oxynitride (SiON) films of ~1 μm thickness were made by dip coating and subsequent thermal treatment of a preceramic polymer: perhydropolysilazane (PHPS). X-ray photoelectron spectroscopy was used to analyze the surface of a series of SiON films annealed in air between room temperature and 800°C. Results reveal that the progressive changes in the bonding states of silicon, oxygen, and nitrogen due to different degrees of annealing lead to a systematic evolution of atomic ratios of the films. It is shown that PHPS forms a unique amorphous SiOxNy material upon annealing in air up to 800°C with evolving compositions, instead of a mixture of Si3N4 and SiO2.