Strain relaxation of GaAs/Ge crystals on patterned Si substrates
Strain relaxation of GaAs/Ge crystals on patterned Si substrates
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DOI：
10.1063/1.4861864
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发表时间：
2014-01
影响因子：
4
通讯作者：
Jizhong Li;J. Bai;Ji-Soo Park;B. Adekore;K. Fox;M. Carroll;Anthony Lochtefeld;Z. Shellenbarger
中科院分区：
文献类型：
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作者：
Jizhong Li;J. Bai;Ji-Soo Park;B. Adekore;K. Fox;M. Carroll;Anthony Lochtefeld;Z. Shellenbarger
我们报道了用金属有机物气相外延法在图案化的硅衬底上无掩模集成几微米大小的GaAs晶体。首先通过低能等离子体增强化学气相沉积在8 μ m高的Si柱上生长2 μ m高的中间Ge台面来桥接晶格参数失配。我们研究的形态演变的GaAs晶体走向全金字塔表现出能量稳定的{111}面与Si柱尺寸减小。用X射线衍射和光致发光测量研究了GaAs晶体中热膨胀系数失配引起的应变释放。的应变释放机制进行了讨论的框架内的线性弹性理论的有限元方法模拟，基于现实的几何形状提取的扫描电子显微镜图像。
We report on the mask-less integration of GaAs crystals several microns in size on patterned Si substrates by metal organic vapor phase epitaxy. The lattice parameter mismatch is bridged by first growing 2-μm-tall intermediate Ge mesas on 8-μm-tall Si pillars by low-energy plasma enhanced chemical vapor deposition. We investigate the morphological evolution of the GaAs crystals towards full pyramids exhibiting energetically stable {111} facets with decreasing Si pillar size. The release of the strain induced by the mismatch of thermal expansion coefficients in the GaAs crystals has been studied by X-ray diffraction and photoluminescence measurements. The strain release mechanism is discussed within the framework of linear elasticity theory by Finite Element Method simulations, based on realistic geometries extracted from scanning electron microscopy images.