High-Performance Metamorphic InP/GaAsSb/InP “Type-II” DHBTs
Grown on GaAs Substrates (Student Paper)
1)Y. Zeng, 1)H.G. Liu, 1)N.G. Tao, and 1)C.R. Bolognesi,
Semiconductor Device Laboratory (CSDL),
2)Dept. of Electrical & Electronic Engineering, HKUST
We report the fabrication of high-performance metamorphic (MM) InP/GaAsSb/InP DHBTs grown on GaAs substrates which show performances comparable or, in certain respects, superior to similar structures grown on InP substrates. The emitter base junction non-ideality factor is found to be significantly higher in the MM devices when compared to the lattice-matched layers: this is believed related to a significantly rougher emitter base junction compared to layers grown lattice-matched on InP. Current gain cutoff frequencies fT as high as 110 GHz have been achieved with a 30 nm base and a 200 nm collector.