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Full-Text Articles in Physics
Equivalence Of Donor And Acceptor Fits To Temperature-Dependent Hall Data: General Case, David C. Look
Equivalence Of Donor And Acceptor Fits To Temperature-Dependent Hall Data: General Case, David C. Look
Physics Faculty Publications
Recently, it was shown that the usual statistical-mechanical formulation used to fit carrier concentration versus temperature data cannot distinguish between the donor or acceptor nature of one single-charge-state center. Here we generalize that result to include any number of donor and acceptor centers, of arbitrary charge multiplicity, and also show how that by fitting one particular case (e.g., every center assumed to be a donor), all of the other possible cases can be immediately solved by inspection.
Defect Production In Electron-Irradiated, N-Type Gaas, David C. Look, J. R. Sizelove
Defect Production In Electron-Irradiated, N-Type Gaas, David C. Look, J. R. Sizelove
Physics Faculty Publications
Temperature-dependent Hall-effect measurements have been performed on pure, n-type, vapor-phase epitaxial GaAs, irradiated by 1-MeV electrons at room temperature. The energies and production rates of two dominant defect centers, C2 and C3, are as follows: E2 = EC - 0.148, E3 = EC2 = 2.0 and τ3 = 0.5 +/1 0.2 cm-1, in good agreement with deep level transient spectroscopy (DLTS) data. However, the most important result of this study is a very high production rate, τAS ≅ +/- 1 cm-1, for "shallow" acceptors (C …
Photoresistivity And Photo-Hall-Effect Topography On Semi-Insulating Gaas Wafers, David C. Look, E. Pimentel
Photoresistivity And Photo-Hall-Effect Topography On Semi-Insulating Gaas Wafers, David C. Look, E. Pimentel
Physics Faculty Publications
By placing a semi-insulating GaAs wafer on a fiat, rare-earth magnet, and irradiating the surface with two perpendicular slits of light to form a Greek cross configuration, it is possible to perform photoresistivity and photo-Hall-effect topography on the wafer. The technique is nondestructive in that the contacts are tiny, removable In dots which are placed only on the periphery. By varying the wavelength of the light, selective centers, such as EL2, can be mapped. We compare a 1.1-μ, photoexcited electron concentration map with a quantitative EL2 map on a 3-in. undoped, liquid-encapsulated Czochralski wafer.
Photoluminescence In Electrically Reversible (Semiconducting To Semiinsulating) Bulk Gaas, Phil W. Yu, David C. Look, W. Ford
Photoluminescence In Electrically Reversible (Semiconducting To Semiinsulating) Bulk Gaas, Phil W. Yu, David C. Look, W. Ford
Physics Faculty Publications
A photoluminescence study has been made of electrically reversible, bulk, liquid-encapsulated Czochralski GaAs at temperatures 2-300 K. The reversibility from the semiconducting to the semi-insulating state is made by slow or fast cooling, respectively, following a 5-h, 950°C heat treatment in an evacuated quartz ampoule. A donor level at Ec - 0.13 eV and two acceptor levels at Ev + 0.069 eV and Ev + 0.174 eV are produced after the heat treatment. Only the acceptor levels were detected by photoluminescence. A tentative model assigning the acceptor to the intrinsic defect pair VGa-GaAs is discussed.
High Acceptor Production Rate In Electron-Irradiated N-Type Gaas - Impact On Defect Models, David C. Look
High Acceptor Production Rate In Electron-Irradiated N-Type Gaas - Impact On Defect Models, David C. Look
Physics Faculty Publications
Defect production rates have been studied in electron-irradiated GaAs by temperature-dependent Hall-effect (TDR) measurements. The TDH results agree well with deep level transient spectroscopy (DLTS) results for the wen-known electron traps E1, E2, and E3, but conclusively demonstrate a much higher production rate (4 ± 1 cm-1) of acceptors below E3 than the total of all other DLTS traps. These findings strongly affect current defect models, and, e.g., are consistent with the existence of Ga sublattice damage, not seen before.
Comparison Of Low-Energy Seismic Sources In Till, Paul J. Wolfe, B. H. Richard, Dale V. Dailey, James R. Plomer
Comparison Of Low-Energy Seismic Sources In Till, Paul J. Wolfe, B. H. Richard, Dale V. Dailey, James R. Plomer
Physics Faculty Publications
No abstract provided.
Equivalence Of Donor And Acceptor Fits Of Temperature-Dependent Carrier-Concentration Data, David C. Look, J. R. Sizelove
Equivalence Of Donor And Acceptor Fits Of Temperature-Dependent Carrier-Concentration Data, David C. Look, J. R. Sizelove
Physics Faculty Publications
It is shown that the usual charge-balance analysis of temperature-dependent carrier-concentration data cannot distinguish between the donor and acceptor behavior of a center which is emitting carriers to a particular band, even though the statistics are different in the two cases. Other data, such as mobility or analytical results are needed to make the distinction.
Electrical Characterization Of Ion Implantation Into Gaas, David C. Look
Electrical Characterization Of Ion Implantation Into Gaas, David C. Look
Physics Faculty Publications
Recent advances in the characterization of ion‐implanted samples have included whole wafer mapping (topography) and depth profiling techniques. We review several methods for mapping electrical parameters, including the dark‐spot resistance (DSR), and the microwave photoconductance techniques. In addition, we suggest a new photo‐Hall technique which would allow mobility and carrier‐concentration mapping as well as that of resistivity . Finally, we review methods for obtaining ρ, μ, and depth profiles, with particular emphasis on the application of the magnetoresistance techniques in actual field‐effect transistor structures.