Selective growth of vertical silicon nanowire array guided by anodic aluminum oxide template

Abstract

We report on the selective growth of vertical silicon nanowire arrays guided by an anodic aluminum oxide (AAO) template without the introduction of any metallic catalyst. Gas-source molecular beam epitaxy using disilane as a source gas was carried out. The growth conditions such as flow rate and growth temperature were changed to optimize the Si nanowire growth. It was found that the selective growth was promoted at a flow rate of 0.5 sccm, whereas the selective growth was poor at high flow rates of 1 and 2 sccm. One-micrometer-long Si nanowire arrays were obtained at a low flow rate of 0.5 sccm only at the growth temperature of 700 °C. The obtained Si grown at a temperature of 650 °C exhibited conglomerated structures with Si grains piled up inside the nanopores of the AAO template. We found that increasing the growth temperature and decreasing the flow rate are useful for improving the growth selectivity.