InP/In/sub 0.53/Ga/sub 0.47/As/InP double heterojunction bipolar transistors on a GaAs substrate using InP metamorphic buffer layer

Summary form only given. We report InP-based DHBTs grown on GaAs using InP as the metamorphic buffer layer. While AlGaAsSb and InAlAs have also been explored as buffer layers, the InP layers grown in our laboratory have substantially better thermal conductivity-16.1 W/mK for InP, compared with 10.5 W/mK for InAlAs and 8.4 W/mK for AlGaAsSb. With a typical HBT geometry and 2/spl times/10/sup 5/ W/cm/sup 2/ dissipation, a thermal analysis indicates that the use of the InP buffer layer will reduce the operating junction temperature by 16-39 /spl deg/C, a difference which can have a substantial impact upon device reliability.