Surface morphology of Si(111)‐(7×7) under an external isotropic tensile stress
Surface morphology of Si(111)‐(7×7) under an external isotropic tensile stress
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各向同性外拉应力下Si(111)-(7×7)的表面形貌
DOI：
10.1116/1.579737
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
I. Tsong
中科院分区：
文献类型：
--
作者：
Y. Wei;Lian Li;I. Tsong
设计了一种特殊的应变台，用于扫描隧道显微镜（STM）在高温下对Si（111）表面施加各向同性拉伸应力。拉伸后，将表面冷却至室温，并对拉伸后的表面进行STM成像。观察到沿< 110 >方向的滑动步长，单原子层高度为3.1 A。滑动阶跃是由（a/2）[110]型位错的传播引起的，这种位错是由于在块体中发生{111}面滑移引起的。尽管施加了高达1%的各向同性应变，但在Si（111）表面并未观察到预期的（7×7）→c（2×8）相变，这可能是因为应变被{111}面的滑移所吸收。然而，在应变表面最大的阶地上发现了大型（5×5）单层岛屿。
A special strain stage was designed for a scanning tunneling microscope (STM) to apply an isotropic tensile stress on a Si(111) surface at elevated temperatures. After straining, the surface was allowed to cool to room temperature and STM images of the strained surface were taken. Glide steps along 〈110〉 directions with single atom‐layer height of 3.1 A were observed. The glide steps were caused by the propagation of a dislocation of the type (a/2) [110] due to the slip of {111} planes occurring in the bulk. Despite the application of up to 1% isotropic strain, the anticipated (7×7)→c(2×8) phase transition was not observed on the Si(111) surface probably because the strain was taken up by the slippage of {111} planes. However, large (5×5) monolayer islands were found on the largest terraces of the strained surface.