使用X射线衍射技术判定SiC单晶体的结构和极性

使用四圆衍射仪和双晶衍射技术，分析了SiC体单晶的结构和极性．SiC单晶体由化学气相淀积法获得．六方｛1015｝极图证明了该单晶结构为6H型．三轴晶衍射中的ω模式衍射强度的差异判定了该单晶的Si终端面和C终端面，即极性面。两个面的一、二、三级衍射强度的测量比值与经过散射因子修正后计算的结构振幅平方比值｜F（000L）｜２／｜F（000L）｜２非常吻合．因此，利用极性面的衍射强度差异，可以方便、严格地判断具有类似结构如2H｛0001｝、4H｛0001｝及3C-SiC｛111｝的极性．

Determination of Structure and Polarity of SiC Single Crystal by X-Ray Diffraction Technique

Structure and polarity of the SiC single crystal have been analyzed with the four-circle X-ray diffraction method by a double-crystal diffractometer.The hexagonal ｛1015｝ pole figure shows that this SiC sample has a 6H modification.The difference between the integrated intensities measured by ω scan in the triple-axis diffraction setup finds some convincing evidence that the surface is either a Si-terminated face or C-terminated face.The experimental ratios of ｜F（000L）｜２／｜F（000L）｜２ are in good agreement with the calculated ones after the dispersion corrections to the atomic scattering factors (L=6,12 and 18,respectively).Thus,this measurement technique is convenient for the application of the materials with remarkable surface polarity.