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

Jae Sung Rieh, Kimball M. Watson, Fernando Guarin, Zhijian Yang, Ping Chuan Wang, Alvin J. Joseph, Greg Freeman, Seshadri Subbanna

Research output: Contribution to journalArticlepeer-review

40 Citations (Scopus)


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 JC = 34 mA//μm2. With a novel projection technique based on accelerated-current stress, a current gain shift of less than ∼15% after 106 h of operation is predicted at T = 140°C. Degradation mechanisms for the observed dc parameter shifts are discussed for various VBE regions, and the separation of current stress effect from 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 a long-term operation at the high operation current density.

Original languageEnglish
Pages (from-to)31-38
Number of pages8
JournalIEEE Transactions on Device and Materials Reliability
Issue number2
Publication statusPublished - 2003 Jun
Externally publishedYes


  • Bipolar transistors
  • Reliability
  • Stress measurement

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Safety, Risk, Reliability and Quality
  • Electrical and Electronic Engineering


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