Simulation study of the DC and AC characteristics of an improved InGaP/GaAs heterostructure-emitter bipolar transistor (HEBT) with an InGaP wide bandgap collector

In this work, an improved InGaP/GaAs heterostructure-emitter bipolar transistor (HEBT) with an InGaP wide bandgap collector is investigated. In the emitter-base region, the thin narrow bandgap n-type GaAs layer is sandwiched between a wide bandgap N-type InGaP confinement layer and a narrow bandgap p-type GaAs base layer. In the collector-base structure, an undoped 30 A/spl ring/-thick GaAs spacer and a heavily doped 30 A/spl ring/-thick GaAs layer are inserted between the base and the collector. Due to the absence of potential spike both at base-emitter and base-collector junctions, the proposed device shows the lower offset and saturation voltages.