Title :
Enhancing the Speed of SiGe HBTs Using fT-Doubler Techniques
Author :
Yuan, Jiahui ; Cressler, John D.
Author_Institution :
Sch. of Electr. & Comput. Eng., Georgia Inst. of Technol., Atlanta, GA
Abstract :
A peak fT of 325 GHz is achieved, for the first time, in a 130 nm, 200 GHz, 3rd-generation SiGe HBT technology at 300 K, by utilizing fT-doubler techniques. This speed enhancement is equivalent to gaining an additional generational node (from 3rd to 4th), with no underlying change to the transistor profile or lithography. The fT-doubler can be treated as a single transistor unit cell during circuit design, which is verified by the investigation of its small-signal equivalent circuit. Reduced Cpi is demonstrated to be the root origin of the fT-enhancement. The impact of emitter geometry on performance is investigated. A record fT of 438 GHz is achieved at 93 K.
Keywords :
Ge-Si alloys; equivalent circuits; frequency multipliers; heterojunction bipolar transistors; HBT; SiGe; fT doubler techniques; frequency 200 GHz; frequency 325 GHz; frequency 438 GHz; generational node; size 130 nm; speed enhancement; temperature 300 K; temperature 93 K; Capacitance; Circuit synthesis; Cryogenics; Drives; Equivalent circuits; Geometry; Germanium silicon alloys; Heterojunction bipolar transistors; Silicon germanium; Temperature;
Conference_Titel :
Silicon Monolithic Integrated Circuits in RF Systems, 2008. SiRF 2008. IEEE Topical Meeting on
Conference_Location :
Orlando, FL
Print_ISBN :
978-1-4244-1855-8
Electronic_ISBN :
978-1-4244-1856-5
DOI :
10.1109/SMIC.2008.19
