Comparative Studies on InGaP/GaAs Heterostructure-Emitter Bipolar Transistors with Tunneling- and Superlattice-Confinement Structures

Abstract

This article first compares the difference of InGaP/GaAs heterostructure-emitter bipolar transistors (HEBTs) with tunneling-and superlattice-confinement structures at room temperature. In the two devices, the insertion of a thin n-GaAs layer at base-emitter junction helps to eliminate the potential spike and a relatively low collector-emitter offset voltage of about 40 mV is observed. The difference of tunneling mechanism will be investigated. Experimentally, a maximum current gain of 285 ( 176) and a current gain cutoff frequency of 26.4 (16.3) GHz are achieved for the tunneling (superlattice) device. As comparing the superlattice device, the tunneling device shows higher current gain at small B-E bias, while it has smaller current gain at large B-E bias.