Molecular-dynamics simulations of solid-phase epitaxy of Si: Growth mechanisms
Molecular-dynamics simulations of solid-phase epitaxy of Si: Growth mechanisms
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Si 固相外延的分子动力学模拟：生长机制
DOI：
10.1103/physrevb.61.8537
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发表时间：
2000
影响因子：
3.7
通讯作者：
A. Shintani
中科院分区：
文献类型：
--
作者：
T. Motooka;K. Nisihira;S. Munetoh;K. Moriguchi;A. Shintani
采用Tersoff势，基于分子动力学（MD）模拟方法，研究了硅在[001]方向固相外延（SPE）过程中的晶体生长过程。作为起始系统，采用包括由多达4096个原子组成的非晶/结晶（a/c）Si界面的四元电池。从MD模拟获得的生长速率的Arrhenius图，我们发现，在较低的温度下的SPE的活化能是在很好的协议与实验值（1.2.7 eV），而它变得更低，在较高的温度。这可以归因于A/C接口结构和SPE机制的差异。在低温区，a/c界面基本上是（001），速率限制步骤是在（001）a/c界面上的二维成核。另一方面，a/c界面主要由高温区域中的{111}小面组成，并且速率限制步骤大概是在与这些小面相关联的扭结位点处被捕获的Si的扩散过程。
Crystal-growth processes of Si during solid phase epitaxy (SPE) in the [001] direction have been investigated based on molecular-dynamics (MD) simulations using the Tersoff potential. A tetragonal cell including an amorphous/crystalline (a/c) Si interface composed of up to 4096 atoms was taken as the starting system. From the Arrhenius plot of the growth rates obtained by MD simulations, we have found that the activation energy of SPE at lower temperatures is in good agreement with the experimental value (≈ 2.7 eV), while it becomes lower at higher temperatures. This can be attributed to the difference in the a/c interface structure and SPE mechanism. In the low-temperature region, the a/c interface is essentially (001) and the rate-limiting step is two-dimensional nucleation on the (001) a/c interface. On the other hand, the a/c interface is predominantly composed of {111} facets in the high-temperature region and the rate-limiting step is presumably a diffusion process of Si to be trapped at the kink sites associated with these facets.