High performance GaInP/GaAs hole barrier bipolar transistors -HBBTs-

The HBBT may be understood as an advanced variant of the well-known heterojunction bipolar transistor. A thin GaInP film (10-20 nm) embedded between emitter and base layer acts as an efficient hole barrier. Combined with several inherent advantages of GaInP the HBBT leads to an attractive alternative to the conventional AlGaAs/GaAs HBT. We report on HBBT devices with different layer sequences and geometries. HBBT devices exhibit almost constant current gain over a wide range of collector current. Maximum oscillation frequencies above 100 GHz are achieved. Applications in the microwave frequency range will be discussed. GaInP/GaAs HBBTs are well described by a T-like small signal equivalent circuit including bias and geometry scaling. A direct parameter extraction method and first load-pull simulations are reported.