InP/InGaAs/InP double heterojunction bipolar transistors with 300 GHz F/sub max/
We report InP/InGaAs/InP Double Heterojunction Transistors (DHBTs) with high breakdown voltages in a substrate transfer process. A device with a 400 /spl Aring/ thick graded base, a 500 /spl Aring/ chirped superlattice base-collector grade and a 2500 /spl Aring/ thick InP collector exhibits f/sub /spl tau//=165 GHz and f/sub max/=300 GHz with breakdown voltage BV/sub CEO/=6 V at a current density, J/sub e/=1/spl middot/10/sup 5/ A/cm/sup 2/. A device with a 400 /spl Aring/ thick graded base, a 500 /spl Aring/ chirped superlattice base-collector grade and a 1500 /spl Aring/ thick InP collector exhibits f/sub /spl tau//=215 GHz and f/sub max/=210 GHz with breakdown voltage BV/sub CEO/=4 V at a current density, J/sub e/=1/spl middot/10/sup 5/ A/cm/sup 2/.