Advanced Process and Modeling on 600+ GHz Emitter Ledge Type-II GaAsSb/InP DHBT

Abstract

An AlInP emitter ledge (EL) has been developed for a Type-II GaAsSb/InP DHBT with doping-graded base. The AlInP emitter ledge has effectively reduced emitter peripheral surface recombination current, thus improving current gain. A 0.25 x 5 μm2 device has demonstrated maximum current gain β = 24, BVCEO = 6.3 V and fT/fMAX = 480/620 GHz. RF performances of 600+ GHz Type II DHBTs with and without emitter ledge have also been compared.