Growth of Straight Silicon Nanowires on Amorphous Substrates with Uniform Diameter, Length, Orientation, and Location Using Nanopatterned Host-Mediated Catalyst

We report a new approach, termed "growth by nanopatterned host-medicated catalyst" (NHC growth), to solve nonuniformities of Si nanowires (NWs) grown on amorphous substrates. Rather than pure metal catalyst, the NHC uses a mixture of metal catalyst with the material to be grown (i.e., Si), nanopatterns them into desired locations and anneals them. The Si host ensures one catalyst-dot per-growth-site, prevents catalyst-dot break-up, and crystallizes catalyst-dot (hence orientating NWs). The growth results straight silicon NWs on SiO2 with uniform length and diameter (4% deviation), predetermined locations, preferred orientation, one-wire per-growth-site, and high density; all are 10-100 times better than conventional growth.