Silicon nanowires grown in nanoporous alumina matrices on 〈100〉 oriented silicon substrates investigated by electron microscopy

We present the growth of single-crystal silicon nanowires using a Vapor Liquid Solid (VLS) method (with gold colloids as catalysts) in nanoporous anodic alumina on 〈100〉 oriented silicon substrate. Results from scanning and transmission electron microscopy are presented and discussed. The nanowires (diameter of 20-50 nm) are forced to grow self-organized perpendicularly to the silicon substrates over large areas, even on 〈100〉 oriented substrates, and are surrounded by an insulating alumina coating. The usual 〈111〉 growth direction can thus be changed over to the direction of the pore.