کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5367740 | 1388372 | 2008 | 5 صفحه PDF | دانلود رایگان |
High-quality relaxed SiGe films on Si (0Â 0Â 1) have been demonstrated with a buffer layer containing modified SiGe (m-SiGe) islands in ultra-high vacuum chemical vapor deposition (UHV/CVD) system. The m-SiGe islands are smoothened by capping an appropriate amount of Si and the subsequent annealing for 10Â min. This process leads to the formation of a smooth buffer layer with non-uniform Ge content. With the m-SiGe-dot multilayer as a buffer layer, the 500-nm-thick uniform Si0.8Ge0.2 layers were then grown. These m-SiGe islands can serve as effective nucleation centers for misfit dislocations to relax the SiGe overlayer. Surface roughness, strain relaxation, and crystalline quality of the relaxed SiGe overlayer were found to be a function of period's number of the m-SiGe-dot multilayer. By optimizing period number in the buffer, the relaxed Si0.8Ge0.2 film on the 10-period m-SiGe-dot multilayer was demonstrated to have a threading dislocation density of 2.0Â ÃÂ 105Â cmâ2 and a strain relaxation of 89%.
Journal: Applied Surface Science - Volume 254, Issue 19, 30 July 2008, Pages 6076-6080