  Ambipolar currents in Germanium p-type nanowire Schottky barrier MOSFETs were
calculated fully quantum-mechanically by using the multi-band k.p method and
the non-equilibrium Green's function approach. We investigated the performance
of devices with 100, 110, and 111 channel orientations, respectively, by
varying the nanowire width, Schottky barrier height, and EOT. The 111 oriented
devices showed the best performance. In comparison to Si as a channel material,
Ge is more desirable because more current can be injected into the channel,
resulting in steeper subthreshold slope and higher on-state current. Our
calculations predict that the Ge channel devices should have an EOT gain of
0.2-0.5 nm over Si channel devices.
