Self-consistent calculations of an electron-wave Y-branch switch

Abstract

A semi-classical model for studying split-gate devices in three dimensions is described. The model, useful at low bias voltages, finds the charge distribution self-consistently in a classical approximation using Poisson’s equation and a Thomas-Fermi electron distribution. This gives a potential in which the Schrödinger equation is solved for electrons near the Fermi level. The transmission coefficients for electrons then give the conductance. The model is used to evaluate the performance of an electron Y-branch switch. This device uses a control voltage to switch an incoming current between two drain leads. A single-mode switch using 80 nm gate separation, needs only 40 mV switching voltage. Multi-mode operation is also demonstrated using 200 nm wide leads. Here 1 V is needed for 10 dB current reduction in one branch.