Growth of Individual Vertical Germanium Nanowires

Vertical germanium nanowires (Figure, inset) can be synthesized on doped and undoped germanium substrates either as high-density arrays or as individual nanowires. The nanowires have smooth surfaces and uniform diameters, and possess (111) lattice fringes with an interplanar distance of 3.26 Å (Figure). Such vertical nanostructures are ideal for fabrication of vertical nanotransistors, such as surround-gate or top-gate transistors, and could be incorporated into other three- dimensional architectures.