Details

Autor(en) / Beteiligte

• Jae-Sung Rieh
• Watson, K.M.
• Guarin, F.
• Zhijian Yang
• Ping-Chuan Wang
• Joseph, A.J.
• Freeman, G.
• Subbanna, S.

Titel

Reliability of high-speed SiGe heterojunction bipolar transistors under very high forward current density

Ist Teil von

• IEEE transactions on device and materials reliability, 2003-06, Vol.3 (2), p.31-38

Ort / Verlag

Piscataway, NJ: IEEE

Erscheinungsjahr

2003

Quelle

IEEE Xplore Digital Library

Beschreibungen/Notizen

• As device scaling for higher performance bipolar transistors continues, the operation current density increases as well. To investigate the reliability impact of the increased operation current density on Si-based bipolar transistors, an accelerated-current wafer-level stress was conducted on 120-GHz SiGe heterojunction bipolar transistors (HBTs), with stress current density up to as high as J/sub C/=34 mA//spl mu/m/sup 2/. With a novel projection technique based on accelerated-current stress, a current gain shift of less than /spl sim/15% after 10/sup 6/ h of operation is predicted at T=140/spl deg/C. Degradation mechanisms for the observed dc parameter shifts are discussed for various V/sub BE/ regions, and the separation of the current stress effect from the self-heating effect is made based on thermal resistance of the devices. Module-level stress results are shown to be consistent with wafer-level stress results. The results obtained in this work indicate that the high-speed SiGe HBTs employed for the stress are highly reliable for long-term operation at high operation current density.