Evaluation of the Transport Properties of GaSb for Bipolar Applications Through Monte Carlo Simulations

GaAs is currently the semiconductor material of choice for high speed, low power applications. Its electronic transport properties are superior to almost all other semiconductors. It is also used in a variety of bipolar applications such as photodetectors and photo-mixers. However, as is well known, the hole mobility and related transport parameters of GaAs are not very good. This is a serious drawback, and poses a potential problem for all applications involving bipolar conductivity. In order to increase the high :frequency limits and high-speed capability of bipolar devices, the choice of an alternative material, therefore, becomes necessary. An important first step towards this goal, would be a theoretical evaluation of the transport properties of other materials, and their comparison with those of GaAs. Here, bulk GaSb is proposed as a possible alternative and an assessment of its electrical response carried out through Monte Carlo simulations. The main goal of this thesis work is to determine the transport parameters of GaSb for both electrons and holes. Numerical simulation results are obtained for quantitative evaluation. To facilitate direct comparisons with GaAs and to validate the numerical software, simulations were also carried out for bulk GaAs material. The results obtained have carefully been compared with the available experimental data. An important contribution of this thesis is a demonstration of superior hole transport characteristics in GaSb. The electronic response is also shown to be good under transient conditions. The overall conclusion is a favorable recommendation of GaSb for bipolar applications, and its merit for further studies in actual devices.