Role of a‐Si:H in lateral growth of crystalline silicon nanowires using Pb and In catalysts

Abstract

Growth of crystalline silicon nanowires at low temperatures by chemical vapour deposition is an important technological challenge for electronic and sensor nanodevices. Here we present a comparative study of crystalline silicon nanowire growth by plasma‐enhanced chemical vapour deposition (PECVD) using lead and indium. We compare two different growth methods that produce either in‐plane or out‐of‐plane crystalline Si nanowires (SiNWs) at temperatures below 400 °C depending on the growth conditions and the catalyst used. The first growth method is based on the deposition of a thin film of amorphous silicon on a substrate at 150 °C and subsequent thermal annealing at 400 °C. The second method uses direct SiNWs growth at 400 °C in PECVD. While the first method produces in‐plane Si nanowires with In and no nanowire growth for Pb, the second method gives rise to out‐of‐plane Si nanowires for In and in‐plane nanowires for Pb. We show that one of the reasons for the difference between these two methods is the properties of amorphous hydrogenated silicon (a‐Si:H), which acts as the source material for in‐plane growth of Si nanowires.