Overshoot in transient and steady-state in GaAs, InP, Ga_.47In_.53As, and InAs bipolar transistors

Abstract

A relatively complete description of the band structure and scattering of GaAs, InP, Ga0.47In0.53As, and InAs has been used to analyze, by the Monte-Carlo method, the switching and quiescent state of bipolar transistors during their turn-on process. Device structures with designs useful for high current densities are used to show the importance of the changes in the overshoot behavior during the switching transient. In logic applications, where breakdown is a significant constraint, broader velocity overshoot profiles and higher maximum overshoot velocities can be obtained over a wider bias range in Ga0.47In0.53As and InP bipolar transistors. InAs bipolar transistors show the largest overshoot and the smallest delay; however, because of their smaller bandgap, the operating bias range of these devices is restricted.