High current (100 mA) InP/InGaAs/InP DHBTs with 330 GHz f/sub max/

We report high f/sub max/ and high current InP/InGaAs/InP DHBT in transferred-substrate technology. The common base device with equivalent emitter size of 128 /spl mu/m/sup 2/ exhibits f/sub max/ of 330 GHz at a current of 100 mA. The common emitter device with emitter area of 64 /spl mu/m/sup 2/ shows f/sub max/ of 371 GHz when biased at 57 mA. The breakdown voltage of these DHBTs is up to 7 V at low current density. All the devices are realized in multi-finger structure that was deliberately designed to improve the thermal stability at high power operation and to reduce the parasitics. To our knowledge, this is the highest f/sub max/ for a DHBT biased at such high current.