Atomic composition profile change of SiGe islands during Si capping
Atomic composition profile change of SiGe islands during Si capping
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DOI：
10.1063/1.2345589
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发表时间：
2006-09
影响因子：
4
通讯作者：
Fu-Ming Li;Yongliang Fan;Xu Yang;Zuimin Jiang;Yueqin Wu;J. Zou
中科院分区：
文献类型：
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作者：
Fu-Ming Li;Yongliang Fan;Xu Yang;Zuimin Jiang;Yueqin Wu;J. Zou
采用原子力显微镜结合选择性刻蚀工艺研究了640 ℃下硅帽盖过程中单个SiGe岛的6%Ge等成分分布变化。在0.32 nm的Si覆盖层厚度下，岛的形状从圆顶转变为{103}面棱锥，随后随着Si覆盖层厚度的增加棱锥面倾角减小。6%Ge的等成分分布表明，Si帽盖前岛基角Si富集程度较高，在Si帽盖过程中岛基角沿着对角线Si混合程度较高。在Si帽盖过程中，岛内部的Si富集演化可以归因于通过表面扩散聚集到岛的帽盖Si原子与来自岛内部的Ge原子通过原子表面偏析和相互扩散的交换，而不是岛与Si衬底之间的界面处的原子相互扩散。此外，还试图根据Si和Ge材料在（001）面的弹性常数各向异性解释Si沿沿着岛基对角线的富集现象。(c)2006年，美国物理学会。
The 6% Ge isocomposition profile change of individual SiGe islands during Si capping at 640 degrees C is investigated by atomic force microscopy combined with a selective etching procedure. The island shape transforms from a dome to a {103}-faceted pyramid at a Si capping thickness of 0.32 nm, followed by the decreasing of pyramid facet inclination with increasing Si capping layer thickness. The 6% Ge isocomposition profiles show that the island with more highly Si enriched at its one base corner before Si capping becomes to be more highly Si intermixed along pyramid base diagonals during Si capping. This Si enrichment evolution inside an island during Si capping can be attributed to the exchange of capped Si atoms that aggregated to the island by surface diffusion with Ge atoms from inside the island by both atomic surface segregation and interdiffusion rather than to the atomic interdiffusion at the interface between the island and the Si substrate. In addition, the observed Si enrichment along the island base diagonals is attempted to be explained on the basis of the elastic constant anisotropy of the Si and Ge materials in (001) plane. (c) 2006 American Institute of Physics.