EXTRINSIC BASE SURFACE RECOMBINATION CURRENT IN SURFACE-PASSIVATED INGAP GAAS HETEROJUNCTION BIPOLAR-TRANSISTORS/

Recombination currents at the emitter mesa periphery of InGaP/GaAs het erojunction bipolar transistors (HBTs) with and without extrinsic base surface passivation layers are evaluated and compared. The obtained i deality factor for the extrinsic base surface recombination curtent in InGaP/GaAs HBTs with the surface passivation layer is 1.6, which is c onsiderably larger than the near-unity value for the HBTs without the surface passivation layer. This indicates a difference in the surface recombination mechanism between passivated and unpassivated InGaP/GaAs HBTs.