Opportunities and pitfalls in patterned self-catalyzed GaAs nanowire growth on silicon

Periodic arrays of self-catalyzed GaAs nanowires (NWs) were grown on Si substrates by gas source molecular beam epitaxy (GS-MBE) using patterned oxide templates. The various challenges of the patterning process that result in undesired outcomes are described, such as pattern transfer by wet/dry etching, oxide thickness variations, and native oxide re-growth. Transmission electron microscopy (TEM) results are used to illustrate each case. In …