THEORETICAL STUDIES OF ELECTRONIC TRANSPORT IN GALLIUM-ARSENIDE MATERIAL AND DEVICES USING AN ENSEMBLE MONTE CARLO METHOD (MODELING)

In this thesis, electronic transport in GaAs material and devices is studied using a many-electron ensemble Monte Carlo (EMC) method. The many-electron scheme is particularly useful since it can include various collective phenomena (e.g., plasmons and self-consistent electric field) as well as both time- and space-dependent simulations.;A one-dimensional EMC device simulation is developed to analyze steady-state and transient electron transport in GaAs planar-doped barrier (PDB) devices. The simulation results confirm velocity overshoot in a PDB diode and extremely fast switching in the subpicosecond range for diode length below 2000 (ANGSTROM). Recently, experimental measurements of the nonstationary hot electron distribution have been proposed by using a PDB transistor. This method is thoroughly examined with an ensemble Monte Carlo simulation. The simulation concludes that this method is able to reflect the overall momentum distribution of injected hot electrons. However, it is insufficient to resolve the detailed features of the distribution function at the base-collector junction since the distribution function is influenced by electron reflections from the collector barrier.;High electron mobility transistors employing the AlGaAs/GaAs heterostructure have attracted considerable interest because of their potential application in high-speed low-power digital integrated circuits. A two-dimensional EMC model including the self-consistent electric field is developed to perform the study of high electron mobility transistors. Particular attention has been paid to hot electron effects, nonstationary effects and real-space transfer. The calculations show that significant velocity overshoot exists under the gate and that the velocity overshoot is basically limited by both k-space and real space transfers. The values of overshoot velocities are much smaller than the velocities obtained from the more conventional drift-diffusion model.;Newly developed Monte Carlo scattering models such as electron-electron scattering, plasmon scattering and coupled plasmon/phonon scattering are discussed in this thesis. The Pauli-exclusion principle is taken into account for the simulation of degenerate transport. Steady-state and transient material transport parameters are calculated and minimum device dimensions necessary for the application of static transport parameters are also determined.