Nonequilibrium and ballistic transport, and backscattering in decanano HEMTs: a Monte Carlo simulation study

High electron mobility transistors (HEMTs) based on III–V semiconductor materials have been investigated as these devices are scaled down to gate lengths of 120, 90, 70, 50 and 30 nm. A standard Monte Carlo (MC) method coupled with the solution of Poisson’s equation is employed to simulate a particle transport. The average particle velocity and the field–momentum relaxation time are studied in detail along the pseudomorphic HEMT (PHEMT) channel for two possible approaches to scaling. Nonequilibrium and ballistic transport dominate at gate lengths of 120 and 70 nm. However, velocity saturation is observed in the 50 nm gate length PHEMT which is due to strong scattering including backscattering. In addition, single and double delta doping designs are also compared. Our work indicates that the 70 nm double doped PHEMT is the most suitable design to further increase the device transconductance. © 2002 IMACS. Published by Elsevier Science B.V. All rights reserved. PACS: 85.30.De; 85.30.Tv; 72.15.Lh; 72.20.Ht