Strain relief mechanisms and the nature of dislocations in GaAs/Si heterostructures
Strain relief mechanisms and the nature of dislocations in GaAs/Si heterostructures
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GaAs/Si 异质结构中的应变消除机制和位错性质
DOI：
10.1063/1.344270
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
J. Narayan
中科院分区：
文献类型：
--
作者：
S. Sharan;J. Narayan
用透射电子显微术研究了GaAs/Si系统中失配位错的形核和滑移。GaAs外延层的不同厚度的电子显微镜（平面和横截面）进行了检查，并保留在膜中的弹性应变已与在界面处的失配位错的平均间距。1000埃厚的GaAs外延层主要包含60°失配位错，平均间距大于平衡位错间距，这意味着失配应变没有完全释放。2000埃和更厚的GaAs外延层主要包含90°错配位错，位错之间的平均间距小于平衡位错间距。根据两个60°位错的反应解释了界面处固着90°位错的形成。基于最小能量考虑开发了一个模型，以确定应变与厚度的关系。理论预测ST…
The nucleation and glide of misfit dislocations in the GaAs/Si system has been investigated using transmission electron microscopy. GaAs epilayers of different thicknesses were examined by electron microscopy (plan and cross section) and the elastic strain remaining in the film has been related to the average spacing of the misfit dislocations at the interface. The 1000‐A‐thick GaAs epilayer contains mostly 60° misfit dislocations with an average spacing larger than the equilibrium dislocation spacing, which implies that the misfit strain is not fully relieved. The 2000‐A and thicker GaAs epilayers contain predominantly 90° misfit dislocations with an average spacing between the dislocations less than the equilibrium dislocation spacing. The formation of sessile 90° dislocations at the interface is explained on the basis of a reaction of two 60° dislocations. A model is developed based on minimum energy considerations to determine the strain‐versus‐thickness relationship. The theoretical predictions of st...