Structural Analysis of Si-Based Nanodot Arrays Self-Organized by Selective Etching of SiGe/Si Films
Structural Analysis of Si-Based Nanodot Arrays Self-Organized by Selective Etching of SiGe/Si Films
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SiGe/Si 薄膜选择性刻蚀自组织硅基纳米点阵列的结构分析
DOI：
10.1143/jjap.50.08lb11
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Akira Sakai
中科院分区：
文献类型：
--
作者：
Masahiko Takahashi;Yoshiaki Nakamura;Jun Kikkawa;Osamu Nakatsukal;Shigeaki Zaimal;Akira Sakai
原子力显微镜（AFM）揭示了纳米点阵列的表面结构的SiGe/Si薄膜，在SiGe-Si界面具有纯刃位错网络的选择性蚀刻制造。通过改变蚀刻时间，可以控制纳米点阵列的组成，允许制造SiGe或Si纳米点阵列。纳米点阵列的表面粗糙度不是源于纳米点本身，而是源于蚀刻之前SiGe/Si膜中位错深度的空间变化。SiGe纳米点阵列中的各个纳米点具有比Si纳米点中的那些纳米点更平滑的轮廓，尽管SiGe和Si纳米点阵列中的纳米点具有相似的高度和直径。单个Si纳米点的粗糙表面是由于较低的蚀刻选择性，这是由于在远离界面的Si衬底中较小的位错对蚀刻反应的影响。透射电子显微镜图像显示形成的外延SiGe纳米点阵列与光滑的表面，这是一致的AFM结果。
Atomic force microscopy (AFM) revealed the surface structures of nanodot arrays fabricated by selective etching of SiGe/Si films that have pure-edge dislocation networks at the SiGe–Si interface. By varying the etching time, it is possible to control the composition of the nanodot arrays, allowing either SiGe or Si nanodot arrays to be fabricated. The surface roughness of the nanodot arrays does not originate from the nanodots themselves, but from the spatial variation in the depth of dislocations in the SiGe/Si films prior to etching. Individual nanodots in SiGe nanodot arrays have smoother profiles than those in Si nanodots although the nanodots in SiGe and Si nanodot arrays have similar heights and diameters. The rougher surface of individual Si nanodots is due to the lower etching selectivity, which results from the smaller dislocation influence on the etching reaction in Si substrates far from the interface. Transmission electron microscopy images reveal the formation of arrays of epitaxial SiGe nanodots with smooth surfaces, which is consistent with the AFM results.