Phosphorus-mediated growth of Ge quantum dots on Si(001)
2005; Elsevier BV; Volume: 278; Issue: 1-4 Linguagem: Inglês
10.1016/j.jcrysgro.2004.12.106
ISSN1873-5002
AutoresJie Qin, Fei Xue, Y. Wang, Lihui Bai, Jian Cui, X.J. Yang, Yong Fan, Zuimin Jiang,
Tópico(s)Silicon Nanostructures and Photoluminescence
ResumoThe influence of pre-deposited phosphorus atoms on the formation of self-assembled Ge quantum dots (QDs) on Si(0 0 1) is investigated by solid-source molecular beam epitaxy (MBE) and atomic force microscopy (AFM). AFM images show that P atoms have a great influence on the size and density of Ge QDs. In the presence of 0.1 ML P atoms, highly uniform self-assembled Ge QDs with a mean base size of 32 nm and an areal density of 1.4×1011 cm−2 are obtained. These QDs are dome shaped with a size distribution width at half-maximum of 8 nm, which have a higher aspect ratio and are more uniform in size than dots obtained with the presence of C atoms. The strain effect on the nucleation and growth of Ge dots induced by P atoms is discussed. In situ annealing reveals the non-metastable nature of the as-grown uniform dots and they are formed under highly kinetically limited condition.
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