NEGF analysis of current oscillation in Germanium nanowire MOSFETs

In this paper, the quantum transport of a Germanium based Gate-All-Around NanoWire Transistor, GAANWT is simulated in nanoscale regime. We have implemented a 3D ballistic simulator based on the Non-Equilibrium Green Function, NEGF, formalism within the effective mass approximation and the mode space approach. Due to low effective mass of the Germanium, it is a promising channel material in nanoscale regime. The size quantization in the nanowires results in the formation of the discrete energy levels along the channel. We have comprehensively investigated key parameters that may affect the normal performance of the Ge based NWT. Simulation results reveal that the current oscillations are observable in the transfer characteristic at the low temperature and drain voltages. It´s observed that these oscillations strongly depending upon the channel thickness in such a way that for thick channels, are visible only at low temperatures. As the channel thickness scales down to 4nm, the oscillations are apparent even at room temperature. The drain current oscillations are gradually disappeared as the drain voltage increases.