Analytical and Numerical Investigation of Noise in Nanoscale Ballistic Field Effect Transistors

The current of ballistic nanoscale MOSFETs is expected to exhibit shot noise, essentially because the electron distribution is very far from equilibrium. Here, we derive an analytical expression of shot noise in fully ballistic MOSFETs and show how it can be computed on the basis of numerical simulations of the DC electrical properties. We show that the power spectral density of shot noise of the drain current is strongly suppressed as an effect of both Pauli exclusion and electrostatic interaction. The amount of such suppression depends on the device structure, and in particular on the gate capacitance. Results on shot noise of the gate current are also shown, since such the leakage current might be significant in nanoscale MOSFETs, for small equivalent oxide thickness.