Dynamical Observations of MBE Grown Thin Films by Ultrahigh Vacuum In-situ Electron Microscopy

超高真空原位电子显微镜对 MBE 生长薄膜的动态观察

基本信息

批准号：
63550543
负责人：
OSAKA Toshiaki
金额：
$ 1.41万
依托单位：
Waseda University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1989
项目状态：
已结题

项目摘要

We have studied homoepitaxial growth processes and surface reconstruction of InSb{111} using ultrahigh vacuum in-situ transmission electron microscopy (UHV in-situ TEM) combined with UHV in-situ reflection electron microscopy (REM). From the TEN observations for InSb(111)B and the REM observations for both reconstructed InSb(111)A and reconstructed InSb(111)B surfaces, the following results were obtained:(1) When the incident fluxes(1:1) of Sb_4 and In_1 are impinged onto the InSb(111)B substrate, the respective molecules form homoepitaxially grown InSb films, leaving an excess molecule Sb^* which does not contribute to the formation of the InSb films. As a result, there exists a critical temperature(T_h) for the condensation of Sb^* molecules. Below T_h, the surface concentration of Sb^*(n_<sb*>) becomes higher than a critical concentration for the condensation (n^c_), SO that two phases (InSb+Sb) grow in a polycrystalline state. However, above T_h as n_<sb*> becomes lower than n^c_, InSb films grow with the 2x2 reconstructed surfaces. This critical temperature is defined as a homoepitaxial temperature. Quantitative interpretations of T_h were discussed.(2) By using UHV in-situ REM, changes in the surface reconstructions of InSb(111)B and InSb(111) A were for the first time observed: for (111)B from the 2x2-Sb to the 3xl-In structure at 420ﾟC and for (111)A from the 2x6-Sb to the 2x2-In structure at 300ﾟC. The particles formed on the InSb(111)B and (111)A surface at 420ﾟC and 450ﾟC respectively, intensely affected the structural transformation in the InSb(111) surface. Also, the particle formed on the InSb(111)B-3xl-In substrate played an important role in spreading the (111)B-3x3-In region which appeared during the homoepitaxial growth of InSb(111)B.

我们使用超高真空透射透射电子显微镜（UHV Initu tem）与UHV内反射电子显微镜（REM）一起研究了INSB {111}的同质增长过程和表面重建。 From the TEN observations for InSb(111)B and the REM observations for both reconstructed InSb(111)A and reconstructed InSb(111)B surfaces, the following results were obtained:(1) When the Incident fluxes(1:1) of Sb_4 and In_1 are impinged onto the InSb(111)B substrate, the respective molecules form homoepitaxially grown InSb films, leaving多余的分子SB^*不影响INSB膜的形成。结果，对于SB^*分子的缩合，存在临界温度（T_H）。在T_H以下，SB^*（N_ <sb*>）的表面浓度变得高于冷凝（N^C_）的临界浓度，因此两个阶段（INSB+SB）在多晶状态下生长。但是，由于n_ <sb*>在t_h上方较低，因此INSB膜随着2x2重建的表面而生长。该临界温度定义为同型温度。讨论了T_H的定量解释。（2）通过使用UHV Initu Rem，第一次观察到INSB（111）B和INSB（111）A的表面重建（111）B和INSB（111）A的变化：对于（111）B，对于（111）B，从2x2-SB从2x2-SB到420 c和（111）A的结构，以及（111）a的结构，以及（111）A。在INSB（111）B和（111）A表面上的颗粒分别在420°C和450°C处形成，强烈影响INSB（111）表面的结构转化。同样，在INSB（111）B-3XL-IN底物上形成的粒子在传播INSB同型生长期间出现的（111）B-3x3-In区域（111）b（111）b。