アモルファスSi₃N₄薄膜の結晶化に及ぼす共存元素および異相界面の影響

抄録

Thin films of amorphous Si₃N₄ were prepared by rf-sputtering method and the effects of titanium, oxygen and chlorine on crystallization were examined. When the Ti-doped amorphous Si₃N₄ was heat-treated in N₂ gas, TiN precipitated in the amorphous matrix above 1100°C. Above 1500°C the TiN precipitates enhanced the direct conversion of amorphous Si₃N₄ to β-Si₃N₄. The conversion rate is proportional to the area of the precipitated TiN surfaces. High resolution electron microscopy revealed that epitaxial growth of β-Si₃N₄ took place on the TiN surface. Chlorine atoms added to amorphous Si₃N₄ led to preferential conversion of amorphous Si₃N₄ to α-Si₃N₄. Oxygen atoms incorporated in amorphous Si₃N₄ influenced the crystallization temperature of the amorphous Si₃N₄.