Title :
An investigation of fT and fmax degradation due to device interconnects in 0.5 THz SiGe HBT technology
Author :
Ulusoy, A. Cagri ; Schmid, Robert L. ; Zeinolabedinzadeh, Saeed ; Khan, Wasif T. ; Kaynak, Mehmet ; Tillack, Bernd ; Cressler, John D.
Author_Institution :
Sch. of Electr. & Comput. Eng., Georgia Inst. of Technol., Atlanta, GA, USA
fDate :
Sept. 28 2014-Oct. 1 2014
Abstract :
In this paper, the authors investigate the impact of device interconnect parasitics on the two most commonly-accepted RF small-signal figures-of-merit, the transit frequency (fT) and the maximum frequency of oscillation (fmax) in state-of-the-art SiGe HBT technology. Simulations and measurement results are provided as a guideline to design an optimum device interconnect scheme to achieve a high fmax. Test structures were characterized with de-embedding structures providing reference planes at the device level and at the top-metal level. Measurements show an fmax of 450 GHz at the device level and at the top-metal level a degradation of only 4% to 430 GHz. These results demonstrate a significant advantage of the SiGe HBT technology compared to ultra-scaled CMOS technology at device speeds approaching a terahertz, and to the best of the authors´ knowledge, demonstrate the highest fmax reported at the top-metal level in any state-of-the-art silicon technology.
Keywords :
Ge-Si alloys; frequency measurement; heterojunction bipolar transistors; interconnections; microwave bipolar transistors; semiconductor device metallisation; semiconductor device models; silicon; submillimetre wave transistors; CMOS technology; HBT technology; RF small-signal figures-of-merit; Si; SiGe; device interconnect parasitics; device interconnect scheme; frequency 0.5 THz; frequency 430 GHz; frequency 450 GHz; heterojunction bipolar transistors; reference planes; silicon technology; transit frequency; CMOS integrated circuits; Degradation; Heterojunction bipolar transistors; Integrated circuit interconnections; Performance evaluation; Radio frequency; Silicon germanium;
Conference_Titel :
Bipolar/BiCMOS Circuits and Technology Meeting (BCTM), 2014 IEEE
Conference_Location :
Coronado, CA
DOI :
10.1109/BCTM.2014.6981317