Orthorhombic distortion of mismatched InXGa1−XAs/InP heterostructures
Orthorhombic distortion of mismatched InXGa1−XAs/InP heterostructures
复制标题
不匹配的 InXGa1−XAs/InP 异质结构的正交变形
DOI：
10.1007/bf03030210
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发表时间：
1991
影响因子：
2.1
通讯作者：
J. Alamo
中科院分区：
文献类型：
--
作者：
B. R. Bennett;J. Alamo
薄的、不匹配的外延层发生四方扭曲，形成相干界面。超过临界厚度，失配位错会缓解应变。这些位错在 (001) 闪锌矿基底上以不对称图案形成。我们表明，这会导致部分松弛、不匹配的 InxGa1−xAs 外延层在 InP 的拉伸或压缩下晶体对称性从四方晶系变为斜方晶系。这种畸变可通过双晶 X 射线衍射和椭圆光度法检测到。当通过 X 射线衍射测量部分松弛外延层的成分时，必须考虑斜方对称性。
Thin, mismatched epilayers tetragonally distort to form coherent interfaces. Beyond the critical thickness, misfit dislocations relieve strain. These dislocations form in an asymmetric pattern on (001) zinc-blende substrates. We show that this results in a change of crystal symmetry from tetragonal to orthorhombic for partially relaxed, mismatched InxGa1−xAs epilayers in either tension or compression on InP. This distortion is detected by both double-crystal x-ray diffraction and ellipsometry. The orthorhombic symmetry must be taken into account when measuring the composition of partially-relaxed epilayers by x-ray diffraction.