On the profile design and optimization of epitaxial Si- and SiGe-base bipolar technology for 77 K applications. I. Transistor DC design considerations

The DC design considerations associated with optimizing epitaxial Si- and SiGe-base bipolar transistors for the 77-K environment are examined in detail. Transistors and circuits were fabricated using four different vertical profiles, three with a graded-bandgap SiGe base, and one with a Si base for comparison. All four epitaxial-base profiles yield transistors with DC properties suitable for high-speed logic applications in the 77-K environment. The differences between the low-temperature DC characteristics of Si and SiGe transistors are highlighted both theoretically and experimentally. A performance tradeoff associated with the use of an intrinsic spacer layer to reduce parasitic leakage at low temperatures and the consequent base resistance degradation due to enhanced carrier freeze-out is identified. Evidence that a collector-base heterojunction barrier effect severely degrades the current drive and transconductance of SiGe-base transistors operating at low temperatures is provided. >

[1]  W. Kauffman,et al.  The temperature dependence of ideal gain in double diffused silicon transistors , 1968 .

[2]  D. Tang,et al.  Bipolar circuit scaling , 1979, 1979 IEEE International Solid-State Circuits Conference. Digest of Technical Papers.

[3]  D. Tang.  Heavy doping effects in p-n-p bipolar transistors , 1980, IEEE Transactions on Electron Devices.

[4]  W. Dumke.  The effect of base doping on the performance of Si bipolar transistors at low temperatures , 1981, IEEE Transactions on Electron Devices.

[5]  R. M. Swanson,et al.  Simultaneous measurement of hole lifetime, hole mobility and bandgap narrowing in heavily doped n-type silicon , 1985, 1985 International Electron Devices Meeting.

[6]  Bernard S. Meyerson,et al.  Low‐temperature silicon epitaxy by ultrahigh vacuum/chemical vapor deposition , 1986 .

[7]  R. M. Swanson,et al.  Measurement of electron lifetime, electron mobility and band-gap narrowing in heavily doped p-type silicon , 1986, 1986 International Electron Devices Meeting.

[8]  J. Woo,et al.  Non-ideal base current in bipolar transistors at low temperatures , 1987, IEEE Transactions on Electron Devices.

[9]  J. Woo,et al.  Optimization of bipolar transistors for low temperature operation , 1987, 1987 International Electron Devices Meeting.

[10]  Denny D. Tang,et al.  Junction degradation in bipolar transistors and the reliability imposed constraints to scaling and design , 1988 .

[11]  Huanjing Chen,et al.  Switching characteristics of poly bipolar circuits at liquid nitrogen temperature , 1988, Proceedings of the 1988 Bipolar Circuits and Technology Meeting,.

[12]  S. Tiwari.  A new effect at high currents in heterostructure bipolar transistors , 1988, IEEE Electron Device Letters.

[13]  K. Jenkins,et al.  On the low-temperature static and dynamic properties of high-performance silicon bipolar transistors , 1989 .

[14]  R. E. Bach,et al.  The ETA 10 liquid-nitrogen-cooled supercomputer system , 1989 .

[15]  D. Tang,et al.  Injection-induced bandgap narrowing and its effects on the low-temperature operation of silicon bipolar transistors , 1989 .

[16]  J.M.C. Stork,et al.  Graded-SiGe-base, poly-emitter heterojunction bipolar transistors , 1989, IEEE Electron Device Letters.

[17]  E. Ganin,et al.  Design issues for SiGe heterojunction bipolar transistors , 1989, Proceedings of the Bipolar Circuits and Technology Meeting.

[18]  K. Shimohigashi,et al.  A high-current-gain low-temperature pseudo-HBT utilizing a sidewall base-contact structure (SICOS) , 1989, IEEE Electron Device Letters.

[19]  D.B.M. Klaassen,et al.  A new recombination model describing heavy-doping effects and low-temperature behaviour , 1989, International Technical Digest on Electron Devices Meeting.

[20]  D. Harame,et al.  Epitaxial-base transistors with ultrahigh vacuum chemical vapor deposition (UHV/CVD) epitaxy: enhanced profile control for greater flexibility in device design , 1989, IEEE Electron Device Letters.

[21]  Judy L. Hoyt,et al.  Bandgap and transport properties of Si/sub 1-x/Ge/sub x/ by analysis of nearly ideal Si/Si/sub 1-x/Ge/sub x//Si heterojunction bipolar transistors , 1989 .

[22]  David L. Harame,et al.  Base profile design for high-performance operation of bipolar transistors at liquid-nitrogen temperature , 1989 .

[23]  John D. Cressler,et al.  Epitaxial-base double-poly self-aligned bipolar transistors , 1990, International Technical Digest on Electron Devices.

[24]  John D. Cressler,et al.  Scaling the silicon bipolar transistor for sub-100-ps ECL circuit operation at liquid nitrogen temperature , 1990 .

[25]  D. Harame,et al.  75-GHz f/sub T/ SiGe-base heterojunction bipolar transistors , 1990, IEEE Electron Device Letters.

[26]  F. Sato,et al.  A 'self-aligned' selective MBE technology for high-performance bipolar transistors , 1990, International Technical Digest on Electron Devices.

[27]  P. Lu.  Low-temperature avalanche multiplication in the collector-base junction of advanced n-p-n transistors , 1990 .

[28]  D.D. Tang,et al.  50-GHz self-aligned silicon bipolar transistors with ion-implanted base profiles , 1990, IEEE Electron Device Letters.

[29]  J.M.C. Stork,et al.  SiGe-base heterojunction bipolar transistors: physics and design issues , 1990, International Technical Digest on Electron Devices.

[30]  J. Cressler.  Silicon bipolar transistor: a viable candidate for high speed applications at liquid nitrogen temperature , 1990 .

[31]  R.K. Kirschman,et al.  Low-temperature electronics , 1990, IEEE Circuits and Devices Magazine.

[32]  Velocity saturation in the collector of Si/Ge/sub x/Si/sub 1-x//Si HBT's , 1990, IEEE Electron Device Letters.

[33]  A Si/SiGe heterojunction bipolar transistor with undoped SiGe spacer for CRYO-BiCMOS circuits , 1990, International Technical Digest on Electron Devices.

[34]  J.M.C. Stork,et al.  Profile leverage in self-aligned epitaxial Si or SiGe base bipolar technology , 1990, International Technical Digest on Electron Devices.

[35]  J. Comfort,et al.  Low temperature operation of Si and SiGe bipolar transistors , 1990, International Technical Digest on Electron Devices.

[36]  D.D. Tang,et al.  The implementation of a reduced-field profile design for high-performance bipolar transistors , 1990, IEEE Electron Device Letters.

[37]  BASE TRANSPORT IN NEAR-IDEAL GRADED-BASE Si/Si,-,Ge,/Si HETEROJUNCTION BIPOLAR TRANSISTORS FROM 150 K TO 370 K , 1990 .

[38]  Modeling and simulation of high-level injection behavior in double heterojunction bipolar transistors , 1990, Proceedings on Bipolar Circuits and Technology Meeting.