Title :
Impact of Scaling on the Inverse-Mode Operation of SiGe HBTs
Author :
Appaswamy, Aravind ; Bellini, Marco ; Kuo, Wei-Min Lance ; Cheng, Peng ; Yuan, Jiahui ; Zhu, Chendong ; Cressler, John D. ; Niu, Guofu ; Joseph, Alvin J.
Author_Institution :
Sch. of Electr. & Comput. Eng., Georgia Inst. of Technol., Atlanta, GA
fDate :
6/1/2007 12:00:00 AM
Abstract :
The inverse-mode operational regime of silicon germanium (SiGe) heterojunction bipolar transistors (HBTs) has to date been largely ignored and is typically dismissed as a viable possibility for circuit applications due to the general perception of its limited dc and ac performance capabilities. In this paper, the inverse-mode performance of four distinct generations of SiGe HBTs is investigated and is found to improve impressively with generational scaling. The physics behind these scaling-induced improvements is examined in detail using a combination of measurements and calibrated simulations. A novel lateral dependence of the inverse-mode base current is identified and is shown to potentially present new opportunities for even larger improvements in inverse-mode performance in SiGe HBTs. A record peak fT in inverse mode of 25 GHz is reported for a prototype fourth-generation device
Keywords :
Ge-Si alloys; heterojunction bipolar transistors; microwave bipolar transistors; 25 GHz; HBT; SiGe; fourth-generation device; generational scaling; heterojunction bipolar transistors; inverse-mode operation; scaling-induced improvements; Bipolar transistors; CMOS technology; Circuits; Germanium silicon alloys; Heterojunction bipolar transistors; Logic devices; NASA; Physics; Silicon germanium; Space technology; Heterojunction bipolar transistors (HBTs); inverse mode; silicon germanium (SiGe) HBTs;
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2007.896570
