An Investigation of Dose Rate and Source Dependent Effects in 200 GHz SiGe HBTs

• Published in: IEEE transactions on nuclear science 2006-12, Vol.53 (6), p.3166-3174
• Main Authors: Sutton, A.K., Prakash, A.P.G., Bongim Jun, Enhai Zhao, Bellini, M., Pellish, J., Diestelhorst, R.M., Carts, M.A., Phan, A., Ladbury, R., Cressler, J.D., Marshall, Paul.W., Marshall, C.J., Reed, R.A., Schrimpf, R.D., Fleetwood, D.M.
• Format: Article
• Language: English
• Subjects: Correlation; Degradation; Devices; Dosage; Dose enhancement; Extraction; Germanium silicon alloys; hardness assurance; hetero-junction bipolar transistor; Heterojunction bipolar transistors; Isolation technology; Low-frequency noise; Oxides; Probes; Protons; Signatures; Silicon germanides; Silicon germanium; silicon-germanium (SiGe); Space technology; Spacers; Testing; total ionizing dose
• ISSN: 0018-9499; 1558-1578
• DOI: 10.1109/TNS.2006.885382

We present an investigation of the observed variations in the total dose tolerance of the emitter-base spacer and shallow trench isolation oxides in a commercial 200 GHz SiGe HBT technology. Proton, gamma, and X-ray irradiations at varying dose rates are found to produce drastically different degradation signatures at the various oxide interfaces. Extraction and analysis of the radiation-induced excess base current, as well as low-frequency noise, are used to probe the underlying physical mechanisms. Two-dimensional calibrated device simulations are employed to correlate the observed results to the spatial distributions of carrier recombination in forward- and inverse-mode operation for both pre- and post-irradiation levels. Possible explanations of our observations are offered and the implications for hardness assurance testing are discussed