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本文报道了由表面形貌观测、X射线双晶衍射、喇曼光谱、透射电镜及深能级解态谱对硅分子束外延中硅衬底在热处理过程中由于热应力、重力等影响导致缺陷产生的研究.由于衬底温度梯度导致样品表面存在位错滑移线,在衬底与外延层界面有着高密度的位错网络,在高的温度梯度区有晶粒间界及多晶存在,并伴有扭曲和不平整,在样品中央部份生长状态较好的锗硅合金层超晶格有部份应变会弛豫而转化为失配位错,这严重影响锗硅超晶格的质量.采用新结构的石英样品座改善了样品温度均匀性,并消除外加应力的影响,己可生长出高质量的锗硅超晶格.
In this paper, the influence of thermal stress and gravity on the silicon substrate in silicon molecular beam epitaxy caused by surface morphology observation, X-ray double crystal diffraction, Raman spectroscopy, transmission electron microscopy and deep level state- Since the substrate temperature gradient causes dislocation slip lines on the sample surface, there is a high-density dislocation network at the interface between the substrate and the epitaxial layer. There is grain boundary and polycrystal in the high temperature gradient region, Accompanied by distortion and unevenness. Some strains in the superlattice of the SiGe layer grown in the central part of the sample are relaxed and converted into misfit dislocations, which seriously affects the quality of the SiGe superlattice The new structure of the quartz sample holder to improve the uniformity of the sample temperature and eliminate the impact of applied stress, have been able to grow high-quality germanium silicon superlattice.