Hot electron and hot hole degradation of UHV/CVD SiGe HBT's

• Published in: IEEE transactions on electron devices Vol. 47; no. 7; pp. 1440 - 1448
• Main Authors: Gogineni, U., Cressler, J.D., Niu, G., Harame, D.L.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.07.2000; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Germanium alloys
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/16.848289

We investigate the degradation in current gain and low-frequency noise of SiGe HBT's under reverse emitter-base stress due to hot electrons (forward-collector stress) and hot holes (open-collector stress). Contrary to previous assumptions we show that hot electrons and hot holes with the same kinetic energy generate different amounts of traps and hence have a different impact on device degradation. These results suggest that the accuracy of using forward-collector stress as an acceleration tool and reliability predictor must be carefully examined. We also present, for the first time, the effect of Ge profile shape on the reliability of SiGe HBT's, as well as discuss measurements on SiGe HBT's as a function of device geometry and temperature.