Fabrication of the semiconductor superlattice by heteroepitaxy and its related evaluation

(1)在室温下，在InSb（111）A和InSb（111）B基片上生长了α-Sn薄膜，这两个基片都具有2 × 2重构表面，它们是通过热清洗和液相外延生长制备的。利用反射高能电子衍射和俄歇电子能谱研究了薄膜的表面相变。对于botil系统，两种类型的膜，每种膜具有不同的厚度8和30单层[ML]，其以逐层模式生长，用于检查作为Sn覆盖的函数的膜的稳定性。在InSb（111）A上的α-Sn膜的情况下，8 ML和30 ML膜的表面都不可逆地经历了从已知的3 × 3结构，经由2 × 2和随后的1 × 1结构的转变。现在发现，终于融化。8 ML薄膜的转变温度比30 ML薄膜的转变温度高10度以上，30 ML薄膜从薄膜表面开始熔化， ...更多信息 在150 ℃时，薄膜表面发生熔化，随后的熔化向薄膜-基体界面发展，而对于8 ML薄膜，在220 ℃时，整个薄膜迅速发生熔化。另一方面，对于α-Sn/InSb（111）B，观察到Sb扩散到Sn膜中。这种现象与α-Sn/InSb（111）A系统的表面相变有很大不同有关。最后，为了讨论α-Sn在InSb（111）A上稳定性的可能机制，采用离散变分Xalpha团簇方法进行了计算. (2)我们用Patterson函数、傅里叶分析和最小二乘修正确定了InSb（111）B-（2 × 2）重构表面的原子结构。Sb三聚体模型充分解释了透射电子衍射和俄歇电子能谱的实验数据。新的结构是Sb三聚体具有3.14 A的Sb-Sb键长，并位于衬底Sb原子上方，具有三重对称性，构成（2x2）结构。少

(1) Thin films of alpha-Sn were grown of InSb(111)A and InSb(111)B substrates at room temperature, both having 2x2 reconstruction surfaces which were prepared by thermal cleaning and liomoepitaxial growth. Surface phase transition of the as-grown films was investigated by using reflection high energy electron diffraction and Auger electron spectroscopy. For botil systems, two types of the films, each having different thickness of 8 and 30 monolayers[ML], which grew with a layer-by-layer mode, were used to examine the stability of the films as a function of Sn coverage. In the case of the alpha-Sn film on InSb(111)A, the surfaces of both the 8ML and the 30ML films irreversibly underwent from the 3x3 structure as already known, via the 2x2 and subsequently the 1x1 structure which werr. nowly found, finally the melting. The transition temperature for the 8ML film were higher more than ten degrees than those for the 30ML except for the melting ; the 30ML film began to melt from the film su … More rface at 150ﾟC and the subsequent melting progressed toward the filmsubstrate interface, whereas for the 8ML film the melting promptly took place throughout the film at 220ﾟC. on the other hand, for alpha-Sn/InSb(111)B diffusion of Sb into the Sn film was observed. The behavior is related to the fact that the surface phase transition in this system is considerably different from that in the alpha-Sn/InSb(111)A system. Finally, in order to discuss possible mechanism for the stability of alpha-Sn on InSb(111)A, the discrete variational Xalpha cluster calculations were performed.(2) we have used Patterson function, Fourier analysis and least square refinement to determine atomic structures of the InSb(111)B-(2x2)reconstructed surface. The proposed Sb trimer model sufficiently explained the experimental data from transmission electron diffraction and Auger electron spectroscopy. The new structure is that an Sb trimer has the Sb-Sb bond length of 3.14 A and is located with three-fold symmetry above substrate Sb atoms consisting of the (2x2) structure. Less