Monte Carlo approach to transient analysis of HBTs with different collector designs

The transient analysis of heterojunction bipolar transistors (HBTs) using the Monte Carlo technique is presented. Three HBT structures with conventional (A), inverted field (B), and undoped (C) collectors were simulated. The transient behavior of the collector currents show that the time constants are 1.466, 0.722, and 0.863 ps at a collector current of 3.5*10/sup 4/ A/cm/sup 2/ for devices A, B and C, respectively. This suggests that the inverted field structure may be the best choice for high-speed applications.>