2-D Monte Carlo simulations of electron transport in n-p-n InAlGaP/GaAs/InGaP heterojunction bipolar transistors for a range of current injection conditions

2-D Monte Carlo simulations of an n-p-n InAlGaP/GaAs/InGaP heterojunction bipolar transistor (HBT) are performed for a range of current injection levels. The carrier dynamics throughout the device are examined in terms of particle densities, fractional occupation of subbands and average velocity and energy distributions. The electric field distribution is also determined in a self-consistent manner and the dependence on the collector current level is studied. Two regimes of operation are observed (with and without base push-out) and the variations in base and collector transit times are calculated for each of these regimes.