AlGaAs/GaAs HBT for high-temperature applications

A high-temperature N-p-n AlGaAs/GaAs HBT with a wide-bandgap emitter which can be operated up to a ambient temperature of 350 degrees C is presented. It is demonstrated that a high Al mole fraction of 0.45 in the emitter in combination with a GaAs base layer yields excellent temperature stability. A useful common-emitter small-signal current gain h/sub FE/ higher than 35 was measured in the range between room temperature and 350 degrees C.<
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