Control of the heteroepitaxal growth on vicinal surfaces

邻近表面异质外延生长的控制

基本信息

批准号：
11555188
负责人：
OSAKA Toshiaki
金额：
$ 4.03万
依托单位：
Waseda University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

In this study, we aimed (i) to prepare a vicinal surface on the Si(111) substrate, (ii) to grow a diamond type of Sn (α-Sn) on the surface, which is the same IV group to Si and is in a large lattice-mismatched relationship with it, and (iii) to control stably its growth morphology.Prior to our experiments, firstly, elastic-strain energy stored at the interface of α-Sn/Si(111) was calculated theoretically using the Keating potential. This calculation gave us the important suggestion that steps on the Si(111) vicinal surface may relax effectively strain energy in the growing film and allow to grow pseudomorphologically α-Sn beyond a critical thickness. On the basis of this result, secondly, we actually grew α-Sn on the 6゜ -inclined vicinal surface, and assessed its process by using reflection high-energy electron diffraction (RHEED) and scanning turneling microscopy (STM).These results are as follows : RHEED patterns showed that terraces on the vicinal substrate used are inclined against the direction normal to the substrate surface and their widths are very narrow. From the STM observation, we gained information of linearity in the step line and nonuniformity in the terrace. Depositing Sn on such vicinal surfaces, we recognized the formation of an adsorption structure having a √3×√3 -R30゜ period. Then, excess Sn forms an α phase, leading to the formation of a facet inclined 19.5゜ form the [11-2] direction of Si(111). Although further growth of Sn causes a phase change from α to β, finally, the whole film becomes α-Sn, presumably stimming from an origin of soft elasticity of Sn.The results show that the utilization of a vicinal surface enables us to control stably the morphology of epitaxicially grown films in the large lattice-mismatched systems.

在这项研究中，我们旨在（i）在Si（111）底物上准备一个替代表面，（ii）在表面上生长钻石类型的SN（α-SN），该钻石类型是与SI的IV组相同的IV组，并且与IT的质量匹配很大，并且与IT的较大匹配关系，并且（III）可以稳定地控制其稳定的生长。在我们的实验之前，首先，使用Keating势计算出存储在α-SN/Si界面（111）界面上的弹性 - 应变能。计算给了我们一个重要建议，即SI（111）替代表面上的步骤可能会在生长的膜中有效应激能量，并允许在临界厚度之外生长假形态学的α-SN。其结果，其次，我们实际上在6゜分配的典型表面上生长α-SN，并通过使用反射高能电子衍射（RHEED）和扫描转向显微镜（STM）评估其过程。这些结果如下：Rheed模式表明，使用的附属底物上的梯田倾向于与底物表面正常的方向，其宽度非常狭窄。从STM观察中，我们获得了步骤线中线性的信息，并且在露台中获得了不均匀性。将SN沉积在此类外表面上，我们认识到具有√3×√3-R30゜时期的添加吸附结构的形成。然后，超过SN形成一个α相，导致形成一个倾斜的倾斜度19.5゜形成了Si的[11-2]方向（111）。尽管SN的进一步生长导致从α到β的相变，但最后，整个膜变成了α-SN，大概是由于SN的软弹性起源而刺激的。结果表明，在大型搭配抗匹配的系统中，情况表面的利用使我们能够稳定地控制了稳定的外式膜形态。