采用新电极结构的PECVD技术 ,在高功率密度、高氢稀释比、低温、偏压及低反应气压的条件下 ,在SiO2 玻璃表面形成双等离子流 ,增加了SiO2 表面SiC的成核几率 ,增强成核作用 ,形成纳米晶。采用高H2 等离子体刻蚀弱的、扭曲的、非晶Si-C及Si-Si和Si-H等键时 ,由于H等离子体对纳米SiC晶粒与非晶态键的差异刻蚀作用 ,产生自组织生长 ,发生晶化。Raman光谱和透射电子衍射 (TEM )的测试结果表明 ,纳米晶SiC是 4H -SiC多型结构。实验结果指出 ,SiC纳米晶的形成必须经过偏压预处理成核 ,并且其晶化存在一个功率密度阈值 ;当低于这一功率密度阈值时 ,晶化消失 ;当超过这一阈值时 ,纳米晶含量随功率密度的提高而增加 ,晶粒尺寸加大。电子显微照片表明晶粒尺寸为 1 0～ 2 8nm ,形状为微柱体。随着晶化作用的加强 ,电导率增加 ,导电机理是渗流作用所致 Using the new electrode structure of PECVD technology, a dual plasma flow is formed on the surface of SiO2 glass under the conditions of high power density, high hydrogen dilution ratio, low temperature, bias voltage and low reaction pressure, which increases the nucleation probability of SiC on SiO2 surface and enhances Nucleation, the formation of nanocrystals. When high-H2 plasma is used to etch weak, distorted, amorphous Si-C and Si-Si and Si-H bonds, due to the differential etching effect of H plasma on the nano-SiC grain and non- Produce self-growth, crystallization occurred. The results of Raman spectroscopy and transmission electron diffraction (TEM) show that the nanocrystalline SiC is 4H-SiC polytype. The experimental results show that the formation of SiC nanocrystals must be pre-treated by bias pretreatment to nucleate, and there is a power density threshold for crystallization. When the power density threshold is below this threshold, the crystallization disappears. When this threshold is exceeded, The crystal content increases as the power density increases, and the grain size increases. Electron micrographs show that the grain size is 10 ~ 28nm, the shape of a micro-cylinder. With the strengthening of crystallization, the conductivity increases, the conductive mechanism is due to seepage