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本文采用了以解理面为衍射基面，直接测量水平弛豫的方法测量了InxGa1-xAs（衬底为GaAs，x～0．1）外延层的应变及其弛豫状态．在以解理面为衍射基面的衍射曲线上清楚地观测到了衬底峰与外延峰的分裂．表明当InGaAs层厚度较厚（～2μm）时，InGaAs外延层与衬底GaAs已处于非共格生长状态，同时发现大失配的InGaAs晶胞并没有完全弛豫恢复到自由状态．其平行于表面法线的晶格参数略大于垂直方向上的晶格参数（△a／a～10-3）．并且晶胞在弛豫过程中产生了切向应变．在考虑了切向应变的基础上准确地确定出了InGaAs层的In组分x．
In this paper, we measured the strain and relaxation state of the InxGa1-xAs (GaAs, x ~ 0.1) epitaxial layer by using cleavage plane as the diffraction base and measuring the horizontal relaxation directly. The cleavage of the substrate peak and the epitaxial peak is clearly observed on the diffraction curve with the cleavage plane as the diffraction base. It shows that when the thickness of InGaAs layer is thicker (~ 2μm), the InGaAs epilayer and the substrate GaAs are in a non-coherent growth state. At the same time, large mismatched InGaAs unit cells are not completely relaxed to free state. The lattice parameter parallel to the surface normal is slightly larger than the lattice parameter in the vertical direction (△ a / a ~ 10-3). And the unit cell produced the tangential strain in the relaxation process. The In composition x of the InGaAs layer is accurately determined on the basis of considering the tangential strain.