Influence of self-assembling growth on the shape and the orientation of silicon nanostructures

Abstract

We have performed local epitaxial growth of silicon nanostructures through micro shadow masks in a self-assembling mode. It is demonstrated that for sub-μm mask apertures the resulting structures are independent of both mask orientation and mask shape, but are determined by the self-assembling growth processes. As this method offers a way to fabricate perfect crystallographic nanostructures without sophisticated lithography, the different growth stages have been investigated in more detail. It has been found that on a (001) substrate four {111} facets dominate the growth of the mesa sidewalls appearing at places where the 〈110〉 axes are tangential to the projected mask aperture. An almost isotropic increase of the {111} facet area has been observed for various shapes of the mask aperture.