GaInP-GaAs Quasi Self-Aligned HBT Technology

A new GaInP-GaAs HBT technology is proposed in which a thin GaInP layer (40 nm) is used both as the emitter and as a passivation layer of the base. High DC current gain up to 40 are obtained, for a high C doping level (6 1019 cm?3) in the base. The GaInP passivation is demonstrated with the achievement of the same DC current gain for small and large devices with emitter-base junction area of 16 to 105 ?m2 respectively. Microwave performnances are discussed and both Ft and Fmax values are around 50 GHz whatever the HBT sizes.