Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7943318 | Superlattices and Microstructures | 2013 | 10 Pages |
Abstract
This paper reports growth of ordered Ge nanodots (NDs) with uniform sizes on silicon substrates using porous alumina membranes (PAMs) as templates. The relationships between substrate temperatures (400-600 °C) and site distribution of Ge NDs are studied. Ordered arrangements of Ge NDs are realized at 400 °C and 500 °C, respectively. Due to joint effect of substrate temperature and restrictions from PAM, an uncommon size change trend is found. At 400 °C, triangular pyramid-like and short cylindrical Ge NDs are obtained with different nanopore aspect ratios of PAMs. A geometrical optic method is used to analyze the mechanism of Ge NDs with such shapes. Raman characterization is utilized to study the strain in Ge NDs. As a result, almost pure Ge content and 1.5% tensile strain are revealed, which are attributed respectively to the low substrate temperature and thermal mismatch among Si substrate, Ge ND and PAM.
Related Topics
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Authors
Wenbo Zhan, Yourui Huangfu, Guqiao Ding, Hui Ye,