InGaAs/InP DHBTs in a Dry-Etched Refractory Metal Emitter Process Demonstrating Simultaneous f tau / f max similar to hbox 430 / 800 Unknown character hbox GHz

We report an hbox InP / In 0.53 hbox Ga 0.47 hbox As / InP double heterojunction bipolar transistor (DHBT) demonstrating simultaneous 430-GHz f tau and 800-GHz f max . The devices were fabricated using a triple mesa process with dry-etched refractory metals for emitter contact formation. The devices incorporate a 30-nm-thick InP emitter semiconductor which enables a wet-etch emitter process demonstrating 270-nm-wide emitter-base junctions. At peak RF performance, the device is operating at 30 hbox mW / mu hbox m 2 with J c = hbox 18.4 Unknown character hbox mA / mu hbox m 2 and V rm ce = hbox 1.64 Unknown character hbox V . The devices show a peak DC common-emitter current gain ( beta ) similar to hbox 20 and V rm BR , CEO = hbox 2.5 Unknown character hbox V .