Effects of nitrogen incorporation on plasma erosion behaviors of oxynitride glasses

Oxynitride glasses have been investigated for their applications to plasma resistant materials in semiconductor processing equipment. With increasing nitrogen content in the glass, the erosion rate under the fluorine plasma decreases to a level much lower than that of typical commercial ceramics for those applications. X-ray photoelectron spectroscopy (XPS) analysis showed that the fluorine content reached a maximum on the surface, and was decreased with increasing depth and oxygen content, while the nitrogen content remained almost constant, irrespective of position. Further XPS analysis revealed the formation of Si–N bonds, resulting in the reinforcement of the glass structures. Measurements of the elastic modulus and molar volume of the glasses also supported the glass reinforcement.