采用分子束外延方法在II-VI族Cd _0.98 Zn _0.02 Te(111)衬底上实现了异系IV-VI族半导体(PbTe)的外延生长. 原子力显微镜(AFM)的表面形貌表征表明, PbTe表面形貌主要由三角形台阶线和螺旋形台阶面构成; 理论计算表明, 螺旋形台阶面的分布受到滑移位错弹性应变能的影响. 通过高分辨透射电镜(HRTEM)观察, 发现在PbTe和Cd _0.98 Zn _0.02 Te界面处存在Frank位错. 分析表明, 这些Frank位错在运动过程中会形成不同的位错组态, 位错组态的相互作用是表面上形成三角形台阶线和螺旋形台阶面的主要原因.

The surface structure of PbTe epitaxial layers on Cd _0.98 Zn _0.02 Te (111) grown by molecular beam epitaxy was studied by atomic force microscope. It is shown that the surface is dominated by terraces with triangular shape and anomalous spiral steps. In order to clarify the origin of the triangular shape and spiral steps, PbTe/Cd _0.98 Zn _0.02 Te heteroepitaxial layers were investigated by using a high-resolution transmission electron microscope (HRTEM). As a result, it is confirmed that the triangular shape and spiral steps originate from the intrinsic Frank dislocations represented in PbTe/Cd _0.98 Zn _0.02 Te interface. Considering the effect of the kinetics of dislocations, it is
revealed that the strain field arising from dislocations affects the formation of spiral steps. The experiments data are in agreement with the calculations based on elasticity theory and dislocation gliding theory.