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

Si/Si/sub 1-x/Ge/sub x//Si N-p-N heterojunction bipolar transistors (HBTs) produced by a chemical vapor deposition technique, limited-reaction processing, were analyzed using electrical measurements to determine properties of strained Si/sub 1-x/Ge/sub x/. The band discontinuities between Si and strained Si/sub 1-x/Ge/sub x/ were found by measuring the collector and base currents as a function of temperature. The electron diffusion coefficient in p-type Si/sub 1-x/Ge/sub x/ was extracted by measuring the change in collector current with Si/sub 1-x/Ge/sub x/ base width. The electron diffusion coefficient perpendicular to the heterointerface in the strained Si/sub 1-x/Ge/sub x/ layers studied here is smaller than that in Si doped to the same level. The reverse leakage currents at the base-emitter junction of the HBTs are smaller than the leakage at the collector-base junction, but in Si control transistors the situation is reversed. The high leakage currents at the collector-base junction in the HBTs are believed to result from the preferred accumulation of misfit dislocations at the strained interface closest to the substrate. >

[1]  John C. Bean,et al.  Measurement of the band gap of GexSi1−x/Si strained‐layer heterostructures , 1985 .

[2]  Toru Tatsumi,et al.  Si/Ge0.3Si0.7/Si heterojunction bipolar transistor made with Si molecular beam epitaxy , 1988 .

[3]  H. Kroemer,et al.  Heterostructure bipolar transistors and integrated circuits , 1982, Proceedings of the IEEE.

[4]  A. R. Moore,et al.  Intrinsic Optical Absorption in Germanium-Silicon Alloys , 1958 .

[5]  John C. Bean,et al.  Stability of semiconductor strained‐layer superlattices , 1986 .

[6]  Lester F. Eastman,et al.  Influence of lattice misfit on heterojunction bipolar transistors with lattice-mismatched InGaAs bases , 1988 .

[7]  J. Hoyt,et al.  Si/Si/sub 1-x/Ge/sub x/ heterojunction bipolar transistors produced by limited reaction processing , 1989, IEEE Electron Device Letters.

[8]  H. Morkoc,et al.  High-speed performance of Si/Si/sub 1-x/Ge/sub x/ heterojunction bipolar transistors , 1989, IEEE Electron Device Letters.

[9]  John C. Bean,et al.  GexSi1−x/Si strained‐layer superlattice grown by molecular beam epitaxy , 1984 .

[10]  Y. Chen,et al.  Subpicosecond InP/InGaAs heterostructure bipolar transistors , 1989, IEEE Electron Device Letters.

[11]  R. Leibenguth,et al.  GexSi1−x strained‐layer heterostructure bipolar transistors , 1988 .

[12]  R. Fischer,et al.  Collector‐emitter offset voltage in AlGaAs/GaAs heterojunction bipolar transistors , 1985 .

[13]  W. G. Opyd,et al.  Growth of GeSi/Si strained‐layer superlattices using limited reaction processing , 1987 .

[14]  G. Patton,et al.  Silicon-germanium base heterojunction bipolar transistors by molecular beam epitaxy , 1988, 1987 International Electron Devices Meeting.

[15]  J. Pfiester,et al.  Improved CMOS field isolation using germanium/boron implantation , 1988, IEEE Electron Device Letters.

[16]  R. People,et al.  Calculation of critical layer thickness versus lattice mismatch for GexSi1−x/Si strained‐layer heterostructures , 1985 .

[17]  T. Ishibashi,et al.  High-frequency characteristics of AlGaAs/GaAs heterojunction bipolar transistors , 1984, IEEE Electron Device Letters.

[18]  John C. Bean,et al.  Pseudomorphic growth of GexSi1−x on silicon by molecular beam epitaxy , 1984 .

[19]  T. Ishibashi,et al.  AlGaAs/GaAs heterojunction bipolar transistors with heavily C-doped base layers grown by flow-rate m , 1989 .

[20]  J. Hayes,et al.  Atomic layer epitaxy grown heterojunction bipolar transistor having a carbon-doped base , 1988, IEEE Electron Device Letters.

[21]  T. Kamins,et al.  Electrical and material quality of Si/sub 1-x/Ge/sub x//Si p-N heterojunctions produced by limited reaction processing , 1989, IEEE Electron Device Letters.

[22]  M. Panish,et al.  InGaAs/InP double-heterostructure bipolar transistors with near-ideal β versus ICcharacteristic , 1986, IEEE Electron Device Letters.

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

[24]  James F. Gibbons,et al.  Limited reaction processing: Silicon epitaxy , 1985 .

[25]  H. Yagi,et al.  A novel bipolar device with low emitter impurity concentration structure , 1974 .

[26]  Y. Fukuda,et al.  Determination of the critical layer thickness of Si1−xGex/Si heterostructures by direct observation of misfit dislocations , 1988 .

[27]  H. C. de Graaff,et al.  Measurements of bandgap narrowing in Si bipolar transistors , 1976 .

[28]  Judy L. Hoyt,et al.  Characterization of p-N Si/sub 1-x/Ge/sub x//Si heterojunctions grown by limited reaction processing , 1988 .