Study of Heteroepitaxial Growth Dynamic on Compound Semiconductor substrates

利用透射电子衍射(TED)、反射高能电子衍射(RHEED)和俄歇电子能谱(AES)动态观察了金属/InSb系统的异质外延生长过程。首先，在动态Al过程观测之前，基于Patterson函数、傅立叶分析和TED相关的最小二乘修正确定了作为衬底的InSb(111)InSb(001)的表面结构：一方面，对于InSb(111)A-2x2，参照空位屈曲模型，测量的强度与表面结构的运动学计算结果吻合得很好；对于InSb(111)B-2x2，提出了一个新的模型，其中Sb三聚体吸附在最外层Sb层的四个顶位。另一方面，对于InSb(OO1)，对观测强度的Patterson分析表明，在InSb(Ool)-C4x4最外层的顶部明显存在二聚体。TED强度…的分布莫尔很好地解释了六原子团簇模型，而不是四原子团簇模型。此外，本文的TED分析表明，在InSb(Ool)-C8x2和C4x4的同一表面上同时存在多个有序排列。其次，我们用超高真空原位TED观察了In和Au在这样建立的InSb(111)InSb(OOI)表面上的生长过程：得到的结果如下：[I]In/InSb(111)(1)In在室温下以岛态生长，在生长的非常早期就具有面心立方结构。(2)In粒子在InSb(111)A-2x2上经历了普通的外延生长，而在InSb(111)B-2x2上，它们旋转到一定程度，可能是由于Sb三聚体的存在。[II]In/InSb(001)在InSb(001)上，In颗粒生长情况与In/InSb(111)A相似；(I)岛状生长，呈金字塔状；(Ii)面心立方结构。此外，不同的生长特征如下：在InSb(001)C4x4和InSb(Ool)-C8x2表面上，In颗粒均沿二聚体阵列排列。[III]Au/InSb(111)A-2x2在该体系中，在生长初期首次观察到Aroo&lt；3&gt；xROO&lt；3&gt；-Au的吸附结构。第三，用RHEED和俄歇电子能谱研究了银和锡的生长过程：[IV]Ag/InSb(111)A-2x2Ag薄膜以STranski-Krastanov模式在InSb(111)A-2x2表面上生长。另一方面，在生长初期，薄膜的(110)晶面平行于InSb(111)晶面生长，取向为Ag&lt；111&/InSb&lt；//InSb&lt；110&gt；而在随后的生长过程中，平行取向与Ag&lt；110&gt；//InSb&lt；211&gt；.[V]Sn/InSb(111)The并存，以逐层方式生长的锡膜的稳定性随覆盖度的增加而降低。在InSb(111)A上，薄膜表面不可逆地经历了3x3结构，经过2x2，随后是1x1，最后是熔化。然而，在InSb(111)B上观察到了明显不同的生长特征；俄歇信号表明与相应的理论曲线有很大的偏差，证明Sb向锡覆盖层中扩散。这种扩散行为严重影响了在InSb(111)B-2x2衬底上生长的α-Sn膜的表面相变。较少

We have used transmission electorn diffraction (TED), reflection high energy electron diffraction (RHEED) and Auger electron spectroscopy (AES) to dynamically observe the heteroepitaxial growth processes in the metals/InSb system. Firstly, prior to the dynamic al process observations, surface structures of InSb(111) InSb(001) that used as a substrate were determined on the basis of the Patterson function, Fourier analysis and least-squares refinement associated with TED : On one hand, for InSb(111)A-2x2, the measured intensities agreed well with the kinematically calculated ones of the surface structure referring to the vacancy buckling model ; for InSb(111)B-2x2, a new model where Sb trimers are adsorbed at a fourfold atop site of the outermost Sb layer has been proposed. On the other hand, regarding InSb(OO1), the Patterson analysis of observed intensities showed the clear presence of dimers on the top of the outermost layer of InSb(OOl)-c4x4. The distribution of the TED intensities … More explained well a six atom cluster model rather than a four atom cluster model. Moreover, the present TED analysis suggested that several ordered arrangements simultaneously exist on one and the same surface of InSb(OOl)-c8x2 as well as c4x4.Secondarly, we have observed growth processes of In and Au on such established InSb(111) InSb(OOI) surfaces by using ultra high vacuumin-situ TED : The results obtained are as follows :[I]In/InSb(111)(1) In grew in an island-state at room temperature and had a fcc structure at the very early stage of growth.(2) In particles experienced an ordinary epitaxial growth on InSb(111)A-2x2, whereas on InSb(111)B-2x2 they rotated to, some extent of degrees, probably being caused by the existence of Sb trimers.[II]In/InSb(001)On InSb(001), In particles grew with situation similar to In/InSb(111)A ; (i) island growth, having a pyramidal shape and (ii) fcc structure. Otherwise, different growth features are as follows : In partilces were arranged along the dimer array in both InSb(001)c4x4 and InSb(OOl)-c8x2 surfaces. In addition, their crystal habit exhibited tent-like, different from the initial growth form of a pyramid.[III]Au/InSb(111)A-2x2In this system, aROO<3>xROO<3>-Au adsorption structure has been for the first time observed at the early stage of growth. From the TED analysis, the structure was determined to be of honeycomb trimer-missing first layer (HT-MFL) type.Thirdly, we have surveyed Ag and Sn growth processes by RHEED and AES : The results are summarized as follows :[IV]Ag/InSb(111)A-2x2Ag films were found to grow with a Stranski-Krastanov mode on the InSb(111)A-2x2 surface. On the other hand, at the very early stage of growth the (110) plane of the film grew parallelly to InSb(111) with the orientation of Ag<111>//InSb<110>, whereas with the subsequent growth, the parallel orientation coexisted with Ag<110>//InSb<211>.[V]Sn/InSb(111)The stability of Sn films which grew with a layer-by-layer mode was lowered with an increase of the coverage. On InSb(111)A, the surface of the film irreversibly underwent from the 3x3 structure, via the 2x2 and subsequently the lxl, finally the melt. However, on the InSb(111)B the predominantly different growth features were observed ; the Auger signals that were indicative of a large deviation from the corresponding theoretical curves evidenced diffusion of Sb into the Sn overlayer. This diffusion behavior heavily influenced the surface phase transition of the alpha-Sn film grown on InSb(111)B-2x2. Less