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Full-Text Articles in Engineering
Zero-Field Time-Of-Flight Measurements Of Electron Diffusion In P+-Gaas, Michael L. Lovejoy, B. M. Keyes, M. E. Klausmeier-Brown, Michael R. Melloch, R. K. Ahrenkiel, Mark S. Lundstrom
Zero-Field Time-Of-Flight Measurements Of Electron Diffusion In P+-Gaas, Michael L. Lovejoy, B. M. Keyes, M. E. Klausmeier-Brown, Michael R. Melloch, R. K. Ahrenkiel, Mark S. Lundstrom
Department of Electrical and Computer Engineering Faculty Publications
Minority electron diffusivities in p+-GaAs-doped NA =~1.4×1018 and ~1019 cm-3 have been measured in zero-field conditions with an extension of the zero-field time-of-flight technique. Extension of the technique to make it applicable to heavily doped p+-GaAs is described and zero-field data are discussed. Unexpectedly, majority carrier drag effects are not evident in a comparison of this data with recently reported high-field data. Low zero-field mobility of electrons in p+-GaAs has important implications for high-speed devices such as heterojunction bipolar transistors.
Experimental Determination Of The Effects Of Degenerate Fermi Statistics On Heavily P‐Doped Gaas, E. S. Harmon, Michael R. Melloch, Mark S. Lundstrom, Michael L. Lovejoy
Experimental Determination Of The Effects Of Degenerate Fermi Statistics On Heavily P‐Doped Gaas, E. S. Harmon, Michael R. Melloch, Mark S. Lundstrom, Michael L. Lovejoy
Department of Electrical and Computer Engineering Faculty Publications
The effects of degenerate Fermi statistics on electron injection currents for p+‐GaAs grown by molecular beam epitaxy are presented. To achieve Be dopant concentrations of greater than 8×1019 cm−3, the substrate temperature during growth was reduced to approximately 450 °C from the usual 600 °C. In this heavily doped material, we measure unexpectedly large electron injectioncurrents which are interpreted in terms of an effective narrowing of the band gap. At extremely heavy doping densities, the Fermi level pushes into the valence band and degenerate Fermi statistics must be taken into account. For doping concentrations greater than …
Transistor-Based Studies Of Heavy Dop-Ing Effects In N-Gaas, M. P. Patkar, Mark S. Lundstrom, Michael R. Melloch
Transistor-Based Studies Of Heavy Dop-Ing Effects In N-Gaas, M. P. Patkar, Mark S. Lundstrom, Michael R. Melloch
Department of Electrical and Computer Engineering Faculty Publications
The n2ieDp product (where n2ie is the np product and Dp is the minority hole mobility) in heavily doped n‐GaAs has been measured by electrical characterization of p‐n‐p GaAs homojunction transistors with base dopings ranging from approximately 1×1017 to 9×1018 cm−3. The measured n2ieDp product decreases as the doping density increases. These results suggest that nie is roughly constant with doping density, in sharp contrast to the large increase observed for p‐type GaAs. This work shows that when designing GaAs bipolar devices, …