A Gummel-Poon model for abrupt and graded heterojunction bipolar transistors (HBTs)

Abstract A Gummel-Poon model for abrupt and graded GaAlAs/GaAs/GaAs heterojunction bipolar transistors (HBTs) is developed. The effect of carrier recombination at the emitter-base heterojunction, space charge region (SCR) width modulation effect, and base-widening effect at large collector currents have been considered. Results from this model are compared with numerical results, experimental results, and results from the most recent analytical models. The results show that the common-emitter current gain behavior in the low collector current region can be predicted more accurately by this model, and that interface and surface recombination affect the current gain more dominantly than the other recombination processes. Dependence of cutoff frequency on collector current obtained from the present model agrees well with the experimental results. This model can also predict both current gain and cutoff frequency falloffs at large collector current. This model can be easily implemented in the SPICE program.

[1]  M. Ettenberg,et al.  Interfacial recombination at /AlGa/As/GaAs heterojunction structures , 1976 .

[2]  K. Morizuka,et al.  Emitter—Base bandgap grading effects on GaAlAs/GaAs heterojunction bipolar transistor characteristics , 1985, IEEE Transactions on Electron Devices.

[3]  O. Nakajima,et al.  Suppression of Emitter Size Effect on Current Gain in AlGaAs/GaAs HBTs , 1985 .

[4]  Juin J. Liou,et al.  Forward-voltage capacitance of heterojunction space-charge regions , 1988 .

[5]  J. Hutchby,et al.  Theoretical analysis of Al x Ga 1-x As-GaAs graded band-gap solar cell , 1976 .

[6]  W. Walukiewicz,et al.  Minority‐carrier mobility in p‐type GaAs , 1979 .

[7]  B. Miller,et al.  Variation of minority-carrier diffusion length with carrier concentration in GaAs liquid-phase epitaxial layers , 1973 .

[8]  T. Ishibashi,et al.  Fabrication and characterization of AlGaAs/GaAs heterojunction bipolar transistors , 1987, IEEE Transactions on Electron Devices.

[9]  M. Tomizawa,et al.  Accurate modeling of AlGaAs/GaAs heterostructure bipolar transistors by two-dimensional computer simulation , 1984, IEEE Transactions on Electron Devices.

[10]  F. A. Lindholm,et al.  High current regimes in transistor collector regions , 1973 .

[11]  Charles Howard Henry,et al.  The effect of surface recombination on current in AlxGa1−xAs heterojunctions , 1978 .

[12]  Osaake Nakajima,et al.  Emitter-Base Junction Size Effect on Current Gain Hfe of AlGaAs/GaAs Heterojunction Bipolar Transistors , 1985 .

[13]  Herbert Kroemer,et al.  Heterostructure bipolar transistors: What should we build? , 1983 .

[14]  Hao-Hsiung Lin,et al.  Transport theory of the double heterojunction bipolar transistor based on current balancing concept , 1986 .

[15]  C. T. Kirk,et al.  A theory of transistor cutoff frequency (fT) falloff at high current densities , 1962, IRE Transactions on Electron Devices.

[16]  Hao-Hsiung Lin,et al.  Current transport across the emitter-base potential spike in AlGaAs/GaAs heterojunction bipolar transistors , 1985 .

[17]  J. Yoshida,et al.  Two-dimensional analysis of emitter-size effect on current gain for GaAlAs/GaAs HBT's , 1987, IEEE Transactions on Electron Devices.

[18]  D. Tremere,et al.  Current gain and cutoff frequency falloff at high currents , 1969 .

[19]  Mark Lundstrom,et al.  An Ebers-Moll model for the heterostructure bipolar transistor , 1986 .

[20]  H. C. Poon,et al.  An integral charge control model of bipolar transistors , 1970, Bell Syst. Tech. J..

[21]  J. Liou.  Investigation of high-current effects on the current gain of AlxGa1−xAs/GaAs/GaAs abrupt heterojunction bipolar transistors , 1989 .

[22]  H. Hovel,et al.  The electrical characteristics of nZnSe—pGe heterodiodes† , 1968 .

[23]  G. Rey,et al.  Electrical behavior of an NPN GaAlAs/GaAs heterojunction transistor , 1979 .

[24]  H. Morkoc,et al.  An investigation of the effect of graded layers and tunneling on the performance of AlGaAs/GaAs heterojunction bipolar transistors , 1984, IEEE Transactions on Electron Devices.

[25]  R.L. Anderson.  Experiments on Ge-GaAs heterojunctions , 1962, IRE Transactions on Electron Devices.

[26]  Federico Capasso,et al.  Optimum emitter grading for heterojunction bipolar transistors , 1983 .

[28]  P. Asbeck,et al.  Numerical simulation of GaAs/GaAlAs heterojunction bipolar transistors , 1982, IEEE Electron Device Letters.

[29]  H. Morkoç,et al.  Doping effects and compositional grading in AlxGa1-xAs/GaAs heterojunction bipolar transistors , 1985, IEEE Transactions on Electron Devices.

[30]  R. Azoulay,et al.  Analysis of d.c. characteristics of GaAlAsGaAs double heterojunction bipolar transistors , 1986 .

[31]  Si‐Chen Lee,et al.  The effect of the base—collector potential spike on the common-emitter I—V characteristics of AlGaAs double-heterojunction bipolar transistors , 1987 .