Enhanced Performance GaAs-Based HBTs using a GaInNAs Base Layer

GaInNAs base layers are enabling performance enhancements over standard GaAs-based HBTs, while preserving the cost effective GaAs platform. We have demonstrated InGaP/GaInNAs HBTs which offer 115 mV lower operating voltage, improved diode symmetry for reduced VCE,offset and Vknee, and superior gain temperature stability as compared with standard InGaP/GaAs HBTs. These enhancements have been realized while simultaneously preserving DC current gain and base doping ( ββ β80, Rsb 530 Ω/†, base thickness -500 Å, base doping ~ 4×10 19 cm 2 ) at the high levels necessary for commercial applications. GaInNAs enables these performance enhancements due to a lower energy gap which advantageously alters relative magnitudes of the collector and various base current components in an HBT