Strain relaxation in Si/Ge/Si nanoscale bars from molecular dynamics simulations
Strain relaxation in Si/Ge/Si nanoscale bars from molecular dynamics simulations
复制标题
分子动力学模拟中 Si/Ge/Si 纳米棒的应变松弛
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
A. Strachan
中科院分区：
文献类型：
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作者：
Y. Park;Hasan Metin Atkulga;A. Grama;A. Strachan
我们使用分子动力学(MD)和反应原子间相互作用势Reaxff来表征外延Si/Ge/Si纳米棒的局域应变与其宽度和高度的函数关系。当纵向应变(沿杆长方向)与几何形状无关时，表面松弛导致Ge截面的横向应变松弛。这种应变松弛随着Ge截面高度的增加和宽度的减小而增加，对于大致为方形的Ge截面，应变松弛是完全的(即，零横向应变)，导致单轴应变状态。这种应变状态在某些微电子应用中是可取的。从与实验非常吻合的MD结果中，我们得到了一个简单的模型来预测这类纳米棒的横向应变作为几何函数的情况。
We use molecular dynamics (MD) with the reactive interatomic potential ReaxFF to characterize the local strains of epitaxial Si/Ge/Si nanoscale bars as a function of their width and height. While the longitudinal strain (along the bars length) is independent of geometry, surface relaxation leads to transverse strain relaxation in the Ge section. This strain relaxation increases with increasing height of the Ge section and reduction in its width and is complete (i.e., zero transverse strain) for roughly square cross sections of Ge leading to a uniaxial strain state. Such strain state is desirable in some microelectronics applications. From the MD results, which are in excellent agreement with experiments, we derive a simple model to predict lateral strain as a function of geometry for this class of nanobars.