【摘要】 采用高分辨 X射线衍射的方法 ,研究了 Hg1 - x Cdx Te液相外延材料的 X射线衍射摇摆曲线和晶格常数随外延层厚度的变化关系 .实验观察到了组分互扩散效应对摇摆曲线和材料晶格常数的影响 .衬底与外延层之间的互扩散区约为 2～ 3μm,在此区域 ,摇摆曲线半峰宽变窄 ,表明从衬底扩散来的 Zn元素降低了界面处的位错密度 .通过测量晶格常数随厚度的变化 ,得到了 Cd组分的纵向分布 ,表面组分低 ,越靠近衬底组分越高 ,组分分布呈非线性变化 ,符合指数衰减关系更多还原

【Abstract】 The change of X ray diffraction rocking curve and the lattice constant with the epilayer thickness in Hg 1- x Cd x Te film grown by liquid phase epitaxy(LPE) is studied by high resolution X ray diffraction method. The effect of composition interdiffusion on the rocking curve and lattice constant is observed in the experiments. The thickness of the interdiffusion region, which locates between the substrate and the epilayer, is about 2～3μm. In this region, the full width at half maximum(FWHM) of the rocking curve decreases, which indicates that the Zn element diffused from the substrate decreases the etching pits density(EPD) around the interface. Through the measurements of lattice constant, the depth distribution of Cd composition is obtained. The composition is lower on the surface but higher when approaching the substrate. The composition profile is nonlinear and accords with an exponential decay relation.更多还原