High-Gain Arsenic-Rich n-p-n InP/GaAsSb DHBTs With $F_{T} \gg \hbox {420} \hbox {GHz}$

Type-II n-p-n InP/GaAsSb/InP double heterostructure bipolar transistors (DHBTs) that are fabricated by optical lithography with a 0.6 times 5 mum² emitter on a 20-nm compositionally uniform GaAsSb_xSb_1-x, carbon-doped base with x = 0.60 and a 75-nm InP collector show current-gain cutoff frequencies as high as 423 GHz at 10 mA/mum² and feature a BV_CEO = 4 V. The pseudomorphic As-rich InP/GaAsSb DHBTs feature a high maximum dc current gain of > 160, owing to the reduction of the type-II conduction band discontinuity DeltaE_C and the associated recombination at the InP/GaAsSb emitter-base interface. This brief demonstrates that the InP/GaAsSb DHBT technology can combine high gain, wide bandwidths, high-current drivability, and structural simplicity.