Joachim N. Burghartz, Andrew C. Megdanis, et al.
IEEE Electron Device Letters
We give the first demonstration that a properly designed silicon bipolar technology can achieve faster unloaded circuit speed at liquid-nitrogen temperature than at room temperature. Transistors were fabricated using a reduced-temperature process employing an in situ arsenic-doped polysilicon emitter contact, a lightly phosphorus-doped epitaxial emitter-cap layer, and a graded SiGe base. At 84K, transistors have a current gain of 500, with a cutoff frequency of 61 GHz, and a maximum oscillation frequency of 50 GHz. ECL circuits switch at a record 21.9 ps at 84K, 3.5-ps faster than at room temperature. Circuits which were optimized for low-power operation achieve a minimum power-delay product of 61 fJ (41.3 ps at 1.47 mW), nearly a factor of two smaller than the best achieved to date at 84K. The unprecedented performance of these transistors suggests that SiGe-base bipolar technology is a promising candidate for cryogenic applications requiring the fastest possible devices together with the processing maturity and integration level achievable with silicon fabrication. © 1994 IEEE
Joachim N. Burghartz, Andrew C. Megdanis, et al.
IEEE Electron Device Letters
Ghavam G. Shahidi, Carl A. Anderson, et al.
IEEE Transactions on Electron Devices
Joachim N. Burghartz, Andrew C. Megdanis, et al.
IEEE Electron Device Letters
Emmanuel F. Crabbé, John D. Cressler, et al.
IEEE Electron Device Letters