6H-SiC表面热氧化SiO2的正电子谱研究

本文将慢正电子湮灭多普勒展宽谱技术，应用于对SiC表面热氧化生长的SiO2特性的研究．S参数和W参数在退火前后的变化，直观的反映出SiO2/SiC表面氧化层中空位型缺陷浓度的改变．通过与SiO2/Si样品的对比，证实C元素及其诱生空位型缺陷的存在，很可能是影响SiO2/SiC氧化层质量和SiC MOS击穿特性的重要因素，后退火工艺可以提高SiO2/SiC中氧化层的致密性．实验表明，慢正电子湮灭多普勒展宽谱是研究热氧化SiO2特性的有效手段

A PAS study on the thermally oxidated SiO2 film on 6H-SiC

In this article, positron annihilation Doppler-spread-spectroscopy was used to study the SiO_2 film by thermal oxidation on 6H-SiC.The change of both S parameter and W parameter before and after annealing could show the void-like defects in SiO_2 on SiC. Compared with SiO_2/Si, the existence of carbon atoms and void-like defects in SiO_2 might be the reasons of low breakdown voltage of SiO_2 /SiC MOS structure. The experiments indicated that, post-annealing processing could improve the quality of the SiO_2 layer. It was also indicated that positron annihilation Doppler-spread-spectroscopy was very useful to study the SiO_2 film by thermal oxidation.