Strain-less directed self-assembly of Si nanocrystals on patterned SiO2 substrate

Strain induced self-assembled Stranski-Krastanov growth of semiconductor islands on patterned substrate has shown great improvement of island size uniformity and spatial order. Here, we show self-assembled Volmer-Weber (V-W) growth of Si nanocrystals (NCs) on patterned SiO2 substrate via traditional chemical vapor deposition method under certain experimental configurations, induced by surface/interface energy competition without strain. A simplified two-dimensional theoretical model is developed to elucidate V-W island nucleation on the pattern substrate with varied morphologies, which shows good consistency with the experimental results. Our studies provide a general guidance for directing the growth and self-assembly of NCs on non-planar oxide substrates. VC 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4749269]