Collector-top GaAs/AlGaAs heterojunction bipolar transistors for high-speed digital ICs

Abstract

GaAs/AlGaAs collector-top heterojunction bipolar transistors with magnesium and phosphorus double-implanted external bases were fabricated. A cutoff frequency of 17 GHz and a gate delay time of 63 ps for DCTL were obtained. These results indicate the potential of collector-top HBTs for high-speed ICs.