Monte Carlo simulations of electron transport in bulk GaN and AlGaN-GaN heterostructures

Calculations of the electronic mobility and drift velocity have been carried out for bulk GaN and AlGaN-GaN heterojunctions based on a Monte Carlo approach. The bulk calculations were intended to serve as a validity check of the simulation model and yielded a set of best-fit transport parameters. Wurtzite GaN has been shown to have superior steady state drift velocity characteristics over both GaAs and the zinc blende phase of GaN. Electron mobility in HFET structures has been analyzed taking account of polarization effects, degeneracy and interface roughness scattering. Degeneracy is shown to play an important role, especially at large gate bias values. Very good agreement with available experiments has been obtained. Our results underscored the dominance of interface roughness scattering, and demonstrated that a parameterized model based on a weak-perturbation, Born approximation theory can yield sufficiently accurate results.