Abstract
In this paper, two approaches to enhance the breakdown voltage in InP-based lattice matched HEMT (InP-LMHEMT) have been investigated by means of a Monte Carlo simulator. In the first we have studied the effects of channel thickness on the breakdown dynamics. On-state breakdown calculations show that channel shrinking results in an enhancement of breakdown voltages. This study shows a frequency dependence of breakdown voltage which is relevant for power rf device applications. In the second approach the effect of a body contact (BC) to quench the breakdown effects and increase the breakdown voltage in InP-LMHEMT is reported. On-state and off-state breakdown results show that the BC prevents holes generated by impact ionization (II) from accumulating in the channel and the buffer, inhibiting the parasitic bipolar effect (PBE). This improves the breakdown behavior and extends the range of the usable drain voltages.