Near-ideal I-V characteristics of GaInP/GaAs heterojunction bipolar transistors

GaInP/GaAs heterojunction bipolar transistors (HBTs) have been fabricated and these devices exhibit near-ideal I-V characteristics with very small magnitudes of the base-emitter junction space-charge recombination current. Measured current gains in both 6- mu m*6- mu m and 100- mu m*100- mu m devices remain constant for five decades of collector current and are greater than unity at ultrasmall current densities on the order of 1*10/sup -6/ A/cm/sup 2/. For the 6- mu m*6- mu m device, the current gain reaches a high value of 190 at higher current levels. These device characteristics are also compared to published data of an abrupt AlGaAs/GaAs HBT having a base layer with similar doping level and thickness.<
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