Metal emitter SiGe:C HBTs

SiGe:C heterojunction bipolar transistors (HBTs) offer high cut-off frequencies, f/sub T/, but low open base breakdown voltages, BV/sub CEO/, due to the relatively high current gain, h/sub FE/. In this paper, we show that the integration of a metal emitter, made by complete silicidation of a mono-emitter, increases the base current, I/sub B/ without reducing the collector current, I/sub C/. Hence, the BV/sub CEO/ is increased without affecting the f/sub T/. Furthermore, this metal emitter reduces the emitter series resistance, R/sub E/, and increases the f/sub T/ compared with a mono-emitter. SiGe:C HBTs with f/sub T/=230GHz and BV/sub CEO/=1.8V have been realised using a metal emitter in a self-aligned integration scheme.

[1]  D. Dutartre,et al.  High performance 0.25 /spl mu/m SiGe and SiGe:C HBTs using non selective epitaxy , 2001, Proceedings of the 2001 BIPOLAR/BiCMOS Circuits and Technology Meeting (Cat. No.01CH37212).

[2]  M. Wurzer,et al.  SiGe bipolar technology with 3.9 ps gate delay , 2003, 2003 Proceedings of the Bipolar/BiCMOS Circuits and Technology Meeting (IEEE Cat. No.03CH37440).

[3]  H.G.A. Huizing,et al.  Base current tuning in SiGe HBT's by SiGe in the emitter , 2001, International Electron Devices Meeting. Technical Digest (Cat. No.01CH37224).

[4]  John D. Cressler,et al.  Measurement of collector-base junction avalanche multiplication effects in advanced UHV/CVD SiGe HBT's , 1999 .

[5]  S. Jeng,et al.  SiGe HBTs with cut-off frequency of 350 GHz , 2002, Digest. International Electron Devices Meeting,.

[6]  Vertical profile optimisation of a self-aligned SiGeC HBT process with an n-cap emitter , 2003, 2003 Proceedings of the Bipolar/BiCMOS Circuits and Technology Meeting (IEEE Cat. No.03CH37440).

[7]  H.G.A. Huizing,et al.  The influence of parasitic resistances on the f/sub T/-optimisation of high-speed SiGe-HBTs , 2003, ESSDERC '03. 33rd Conference on European Solid-State Device Research, 2003..

[8]  NiSi integration in a non-selective base SiGeC HBT process , 2005 .

[9]  H. Bender,et al.  Materials aspects, electrical performance, and scalability of Ni silicide towards sub-0.13 μm technologies , 2001 .