Low temperature fabrication of Si02/SiC structure by use of surface nanopores formed by nitric acid oxidation method

我们开发了一种利用硝酸氧化法进行低温形成的方法。氢气处理可使3C-SiC表面原子化扁平化，采用40和68wt%HNO3溶液在120℃以下进行二步硝酸氧化法可获得具有良好电性能的SiO_2/SiO_2结构。在不加氢处理的情况下，流经SiO_2的漏电流密度很高，而在氢处理的情况下，流过SiO_2的漏电流密度可以降低大约六个数量级。我们还利用硝酸蒸汽氧化法在600℃的温度下制备了SiO_2/4H-SiC结构。氧化只从台阶边开始，C面的初始氧化速率是Si面的2.8倍。对于硅面，在界面处形成了SiOC物种，而在C面上没有形成SiOC物种。

We have developed a method of low temperature formation by use of nitric acid oxidation method. 3C-SiC surfaces can be atomically flattened by hydrogen treatment at 400℃, and SiO_2/SiC structure with good electrical characteristics can be formed by two-step nitric acid oxidation method using 40 and 68wt% HNO_3 solutions below 120℃. The leakage current density flowing through SiO_2 is high with no hydrogen treatment, but it can be decreased by approximately six orders of magnitude using the hydrogen treatment. We have also fabricated SiO_2/4H-SiC structure by use of nitric acid vapor oxidation method at 600℃. The oxidation proceeds only from step edges, and the initial oxidation rate for C-face is 2.8 times higher than that for Si-face. For the Si-face, SiOC species is formed at the interface, while it is not present for the C-face.