Microwave performance of a self-aligned GaInP/GaAs heterojunction bipolar transistor

The microwave performance of a self-aligned GaInP/GaAs heterojunction bipolar transistor (HBT) is presented. At an operating current density of 2.08*10/sup 4/ A/cm/sup 2/, the measured cutoff frequency is 50 GHz and the maximum oscillation frequency extrapolated from measured unilateral gain and the maximum available gain are 116 and 81 GHz, respectively, all using 20-dB/decade slopes. These results are compared with other reported high-frequency performances of GaInP HBTs. In addition, these results are compared with AlGaAs/GaAs HBTs having a similar device structure.<
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