Anisotropic resistivity correlated with atomic ordering in p-type GaAsSb
Anisotropic resistivity correlated with atomic ordering in p-type GaAsSb
复制标题
p 型 GaAsSb 中各向异性电阻率与原子排序相关
DOI：
10.1063/1.1406982
复制
发表时间：
2001
影响因子：
4
通讯作者：
N. Moll
中科院分区：
文献类型：
--
作者：
V. Fink;E. Chevalier;O. Pitts;M. Dvorak;K. Kavanagh;C. Bolognesi;S. Watkins;S. Hummel;N. Moll
我们已经在未掺杂和碳掺杂的GaAs 1 −xSbx薄膜（0.4<x<0.6）中检测到三重和六重横向有序，使用平面视图和横截面透射电子显微镜。样品通过有机金属气相外延生长在取向的InP（001）衬底上，温度范围为500至600 °C。 平行于[110]面内方向调制的自发横向超晶格具有两个周期性，6或3倍于随机合金110的晶格参数。有序度或畴尺寸随生长温度而增加，如通过增加图像中超晶格条纹的清晰度以及通过在选定区域衍射图案中从条纹到超晶格斑点的变化所看到的。虽然形成机制可能是表面介导的过程，但在压缩或拉伸方面，或者在未掺杂或碳掺杂的样品之间，没有检测到任何差异。有序性与[110]/[11_0]薄层电阻比高达150%的大各向异性相关。
We have detected three- and six-fold lateral ordering in undoped and carbon-doped GaAs1−xSbx films (0.4<x<0.6), using plan-view and cross-sectional transmission electron microscopy. The samples were grown by organometallic vapor phase epitaxy onto oriented InP (001) substrates, at temperatures ranging from 500 to 600 °C. Spontaneous lateral superlattices with modulation parallel to the [110] in-plane direction occur with two periodicities, 6 or 3 times the random alloy 〈110〉 lattice parameter. The degree of ordering or domain size increases with growth temperature, as seen by increasing definition of the superlattice fringes in the images, and by a change from streaks to superlattice spots in the selected area diffraction patterns. While the formation mechanism is likely a surface mediated process, no differences were detected for samples in compression or tension, or between those undoped or carbon doped. The ordering correlates with large anisotropies of up to 150% in [110]/[11_0] sheet resistance ratios.