An InGaAs/InP DHBT With Simultaneous $\text{f}_{\boldsymbol \tau }/\text{f}_{\text {max}}~404/901$ GHz and 4.3 V Breakdown Voltage
We report an InP/InGaAs/InP double heterojunction bipolar transistor fabricated in a triple-mesa structure, exhibiting simultaneous 404 GHz fτ and 901 GHz fmax. The emitter and base contacts were defined by electron beam lithography with better than 10 nm resolution and smaller than 20 nm alignment error. The base-collector junction has been passivated by depositing a SiNx layer prior to benzocyclobutene planarization, improving the open-base breakdown voltage BVCEO from 3.7 to 4.3 V.