Characteristic Features of 1-D Ballistic Transport in Nanowire MOSFETs

In this paper, we theoretically investigate characteristic features of 1-D, ballistic transport in nanowire (NW) MOSFETs. An analytic model at $T= 0$ K is first derived using the top-of-the-barrier ballistic transport model. When the drain voltage is low, this model shows that the drain current increases stepwise with increasing gate voltage, and the transconductance vs. gate voltage displays spikes. These features are the most evident signatures of 1-D transport. Next, we examine the finite-temperature performance numerically and show how $I$-$V$ characteristics change as device parameters and temperature are varied. Finally, recently reported silicon NW gate-all-around MOSFETs are analyzed with our model. We show that some quantum features of these experiments can be explained with our simple, ballistic model. This approach may be a possible tool for subband spectroscopy and device performance assessment.