Device scaling and application trends for over 200GHz SiGe HBTs

We discuss issues and solutions for scaling of SiGe HBT devices through f/sub T/ = 350GHz. Trends in peak f/sub T/ current density J/sub CP/ and avalanche multiplication M-I are shown for devices with f/sub T/ ranging from 50GHz to 350GHz, and discussed in the context of device operation and reliability. The over 10/spl times/ current density increase observed across this f/sub T/ range may be managed by reducing emitter width and maintaining a low device thermal resistance. We show that the over 20/spl times/ avalanche current increase must be accompanied by a reduction in base resistance to maintain sufficiently high instability voltage. We also discuss the degradation from avalanche hot carriers and find this acceptable looking forward. From the circuit point of view, reversal in base current resulting from avalanche must be managed in the model and in the circuit design.

[1]  A new "mixed-mode" base current degradation mechanism in bipolar transistors , 2002, Proceedings of the Bipolar/BiCMOS Circuits and Technology Meeting.

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

[3]  Hans-Martin Rein,et al.  Influence of impact-ionization-induced instabilities on the maximum usable output voltage of Si-bipolar transistors , 2001 .

[4]  B. Jagannathan,et al.  A 0.18 /spl mu/m BiCMOS technology featuring 120/100 GHz (f/sub T//f/sub max/) HBT and ASIC-compatible CMOS using copper interconnect , 2001, Proceedings of the 2001 BIPOLAR/BiCMOS Circuits and Technology Meeting (Cat. No.01CH37212).

[5]  B. Achiriloaie,et al.  VI REFERENCES , 1961 .

[6]  J. Rieh,et al.  Structural dependence of the thermal resistance of trench-isolated bipolar transistors , 2002, Proceedings of the Bipolar/BiCMOS Circuits and Technology Meeting.

[7]  B. Jagannathan,et al.  40 Gbit/sec circuits built from a 120 GHz f/sub T/ SiGe technology , 2001, GaAs IC Symposium. IEEE Gallium Arsenide Integrated Circuit Symposium. 23rd Annual Technical Digest 2001 (Cat. No.01CH37191).

[8]  S. Jeng,et al.  Self-aligned SiGe NPN transistors with 285 GHz f/sub MAX/ and 207 GHz f/sub T/ in a manufacturable technology , 2002, IEEE Electron Device Letters.

[9]  Chih-Tang Sah,et al.  Degradation of silicon bipolar junction transistors at high forward current densities , 1997 .

[10]  Alvin J. Joseph,et al.  Wafer level forward current reliability analysis of 120GHz production SiGe HBTs under accelerated current stress , 2002, 2002 IEEE International Reliability Physics Symposium. Proceedings. 40th Annual (Cat. No.02CH37320).

[11]  F. Wang,et al.  Ultra high speed SiGe NPN for advanced BiCMOS technology , 2001, International Electron Devices Meeting. Technical Digest (Cat. No.01CH37224).

[12]  Alain Chantre,et al.  A high-speed low 1/f noise SiGe HBT technology using epitaxially-aligned polysilicon emitters , 1999 .

[13]  Gregory G. Freeman,et al.  Avalanche current induced hot carrier degradation in 200 GHz SiGe heterojunction bipolar transistors , 2003, 2003 IEEE International Reliability Physics Symposium Proceedings, 2003. 41st Annual..