Metamorphic InP/InGaAs double-heterojunction bipolar transistor structure grown on GaAs by solid source molecular beam epitaxy

We report, for the first time, metamorphic InP/InGaAs double-heterojunction bipolar transistor (DHBT) structures grown on GaAs substrates by solid source molecular beam epitaxy (SSMBE). A linearly graded In/sub x/Ga/sub 1-x/P(x:0.48 to 1) buffer layer was used to accommodate the strain relaxation. Mesa-type devices were fabricated and characterized. The devices show promising DC and RF performances, indicating the great potential for SSMBE growth of metamorphic InP/InGaAs HBT structures for high speed and high frequency applications.