Monte Carlo Study of an InAlAs/InGaAs Velocity Modulation Transistor

We report a Monte Carlo study of an InP-based InAlAs/InGaAs velocity modulation transistor (VMT) based on the double-gate high electron mobility transistor (DG-HEMT), a HEMT with two opposite gates controlling the carrier flow through the conducting channel. In the VMT the source and drain electrodes are connected by two channels with different mobility, and electrons are transferred between the channels by changing the gate voltages in differential mode. As a result, the drain current is modulated while keeping the total carrier density constant, thus in principle avoiding capacitance charging/ discharging delays. The numerical analysis of the carrier density and velocity variations with the gate bias in differential mode demonstrates the actual velocity modulation operation of the proposed VMT transistors.