Reliability of high-performance AlInAs/GaInAs heterojunction bipolar transistors under forward bias and temperature stress

We report, for the first time, on the reliability of AlInAs/GaInAs heterojunction bipolar transistors. This is also the first report on the reliability of a high-performance millimeter-wave HBT. Devices with MBE grown base Be doping levels of 5-10*10/sup 19/ cm/sup -3/ and base thickness of approximately 50 nm displayed no sign of Be diffusion under applied bias (i.e. drift in V/sub BE/ or beta ). Excellent stability in DC current gain and base-emitter junction characteristics was observed. Degradation of the base-collector junction was used as failure criteria to project a MTTF of more than 10/sup 7/ hours at 125 degrees C with an activation energy of 1.92 eV.<
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