Controlling threading dislocation densities in Ge on Si using graded SiGe layers and chemical-mechanical polishing
Controlling threading dislocation densities in Ge on Si using graded SiGe layers and chemical-mechanical polishing
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DOI：
10.1063/1.121162
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发表时间：
1998-04-06
影响因子：
4
通讯作者：
Fitzgerald, EA
中科院分区：
文献类型：
--
作者：
Currie, MT;Samavedam, SB;Fitzgerald, EA
本文提出了一种利用梯度SiGe层和化学机械抛光（CMP）控制Ge/Si中穿透位错密度的方法。这种方法使我们能够生长一个轻松的梯度缓冲区，100%的锗，而不会增加通常在厚梯度结构中观察到的穿透位错密度。该样品的特征在于透射电子显微镜，蚀坑密度，原子力显微镜，Nomarski光学显微镜，和三轴X射线衍射。与未实施CMP的其他松弛梯度缓冲区相比，该样品在穿透位错密度和表面粗糙度方面表现出改善。我们还进行了工艺修改，以消除由于气相成核和裂纹，由于热失配应变颗粒。我们已经在Si上实现了弛豫Ge，其穿透位错密度为2.1 × 10（6）cm（-2），并且我们期望进一步的工艺改进将导致在体Ge衬底的数量级上更低的穿透位错密度。(C)1998年美国物理学会。[S0003-6951（98）01214-5]。
A method of controlling threading dislocation densities in Ge on Si involving graded SiGe layers and chemical-mechanical polishing (CMP) is presented. This method has allowed us to grow a relaxed graded buffer to 100% Ge without the increase in threading dislocation density normally observed in thick graded structures. This sample has been characterized by transmission electron microscopy, etch-pit density, atomic force microscopy, Nomarski optical microscopy, and triple-axis x-ray diffraction. Compared to other relaxed graded buffers in which CMP was not implemented, this sample exhibits improvements in threading dislocation density and surface roughness. We have also made process modifications in order to eliminate particles due to gas-phase nucleation and cracks due to thermal mismatch strain. We have achieved relaxed Ge on Si with a threading dislocation density of 2.1 X 10(6) cm(-2), and we expect that further process refinements will lead to lower threading dislocation densities on the order of bulk Ge substrates. (C) 1998 American Institute of Physics. [S0003-6951(98)01214-5].