Study of Heteroepitaxial Growth Dynamic on Compound Semiconductor substrates

化合物半导体衬底异质外延生长动力学研究

基本信息

批准号：
02452248
负责人：
OSAKA Toshiaki
金额：
$ 3.52万
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 (B)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

项目摘要

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

我们使用透射电子衍射（TED）、反射高能电子衍射（RHEED）和俄歇电子能谱（AES）来动态观察金属/InSb系统中的异质外延生长过程。基于 Patterson 函数、傅里叶分析和与TED：一方面，对于 InSb(111)A-2x2，测量的强度与参考空位屈曲模型的表面结构运动学计算的强度非常吻合；对于 InSb(111)B-2x2，这是一种新模型，其中 Sb已提出三聚体吸附在最外层 Sb 层的四重顶部位置。另一方面，对于 InSb(OO1)，观察到的帕特森分析。强度显示在 InSb(OOl)-c4x4 最外层的顶部明显存在二聚体。TED 强度的分布很好地解释了六原子簇模型而不是四原子簇模型。分析表明，InSb(OOl)-c8x2 和 c4x4 的同一个表面上同时存在多种有序排列。其次，我们观察到了 In 和 Au 在这种结构上的生长过程。 InSb(111) InSb(OOI)表面采用超高真空原位TED：得到的结果如下：[I]In/InSb(111)(1) In在室温下以岛状生长，具有(2) In 颗粒在 InSb(111)A-2x2 上经历了普通外延生长，而在 InSb(111)B-2x2 上则经历了普通外延生长。旋转到一定程度，可能是由于 Sb 三聚体的存在引起的。[II]In/InSb(001)在 InSb(001) 上，In 颗粒的生长情况与 In/InSb(111)A ) 岛生长类似，具有金字塔形状和(ii) fcc 结构，否则，不同的生长特征如下： InSb(001)c4x4 和 InSb(001)c4x4 中的颗粒均沿着二聚体阵列排列。 InSb(OOl)-c8x2表面，其晶体呈现出习惯帐篷状，与金字塔的初始生长形式不同。[III]Au/InSb(111)A-2x2在该体系中，aROO 3 > xROO <首次在生长早期观察到3>-Au吸附结构，根据TED分析，确定该结构为蜂窝状三聚体缺失第一层（HT-MFL）。第三，我们通过RHEED和AES研究了Ag和Sn的生长过程：结果总结如下：[IV]Ag/InSb(111)A-2x2Ag薄膜被发现在InSb上以Stranski-Krastanov模式生长另一方面，在生长的早期阶段，薄膜的(110)面平行于(111)A-2x2表面生长。 InSb(111)具有Ag<111>//InSb<110>的取向，而随着随后的生长，平行取向与Ag<110>//InSb<211>共存。[V]Sn/InSb(111)以逐层方式生长的Sn薄膜的稳定性随着InSb(111)A上覆盖率的增加而降低，薄膜表面发生不可逆的变化。从 3x3 结构继续，经过 2x2，随后是 1xl，最后是熔化。然而，在 InSb(111)B 上观察到主要不同的生长特征；俄歇信号表明与相应的理论曲线存在很大偏差。明显的 Sb 扩散到 Sn 覆盖层中，这种扩散行为严重影响了在 InSb(111)B-2x2 上生长的 α-Sn 薄膜的表面相变。