ZnSe nucleation on the GaAs(001):Se‐(2×1) surface observed by scanning tunneling microscopy
ZnSe nucleation on the GaAs(001):Se‐(2×1) surface observed by scanning tunneling microscopy
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扫描隧道显微镜观察到 GaAs(001):Se-(2×1) 表面 ZnSe 成核
DOI：
10.1116/1.587799
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发表时间：
1994
影响因子：
1.4
通讯作者：
M. Pashley
中科院分区：
文献类型：
--
作者：
D. Li;M. Pashley
我们利用扫描隧道显微镜（STM）研究了在GaAs（001）：Se-（2×1）表面上通过分子束外延生长ZnSe的初始阶段。GaAs（001）：Se-（2×1）表面是通过在GaAs（001）：Se-（2×4）表面上沉积Se并在520 °C以上退火形成的。它是一种高度有序的（2×1）Se二聚体阵列，因此在结构上类似于Se封端的ZnSe（001）-（2×1）表面，并可能为二维ZnSe生长提供良好的起始表面。然而，我们发现ZnSe通过在GaAs（001）：Se-（2×1）表面上形成三维岛来生长。岛生长几层高，而大部分的Se-终止GaAs表面仍然暴露。我们将我们的STM图像与一个简单的生长统计模型进行了比较，并得出结论：ZnSe在GaAs（001）：Se-（2×1）表面上的粘附系数约为连续ZnSe薄膜上的粘附系数的1/5，而在小ZnSe岛顶部的粘附系数接近于连续ZnSe薄膜上的粘附系数。
We have used scanning tunneling microscopy (STM) to study the initial stages of the growth of ZnSe by molecular‐beam epitaxy on the GaAs(001):Se‐(2×1) surface. The GaAs(001):Se‐(2×1) surface is formed by depositing Se onto the GaAs(001):Se‐(2×4) surface and annealing at above 520 °C. It is a highly ordered (2×1) array of Se dimers, and so is structurally similar to the Se‐terminated ZnSe(001)‐(2×1) surface, and might be expected to provide a good starting surface for two‐dimensional ZnSe growth. However, we find that ZnSe grows by the formation of three‐dimensional islands on the GaAs(001):Se‐(2×1) surface. Islands grow several layers high while much of the Se‐terminated GaAs surface remains uncovered. We have compared our STM images to a simple statistical model of growth and conclude that the sticking coefficient of ZnSe on the GaAs(001):Se‐(2×1) surface is about 1/5 of that on a continuous ZnSe film, whereas the sticking coefficient on top of the small ZnSe islands is close to that on a continuous ZnSe...