Microstructure of epitaxial layers deposited on silicon by ion assisted deposition

We demonstrate the epitaxial growth of silicon with ion assisted deposition on pyramidally structured porous silicon and investigate the microstructure of the epitaxial layer with transmission electron microscopy. The major defects in the grown pyramid structure are stacking faults on the {1 1 1} facets of the pyramids, whereas the epitaxial layers on the {0 0 1} facets are defect-free. The stacking fault density decreases by about three orders with increasing the deposition temperature from 600 to 850°C, but is constant when the ion energy changes. Depending on growth conditions Si-interstitials are built into the layers, which during electron microscopy form so called rod-like defects.