| Synthesis of Mismatched Heterojunction/Substrate Interfaces |
11 OCT 91 |
123 pages |
| Authors:
H. H. Wieder; CALIFORNIA UNIV SAN DIEGO LA JOLLA DEPT OF ELECTRICAL AND COMPUTER ENGINEERIN G
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 | Strained layer InGaAs and InA1As structures have been grown by molecular beam epitaxy on lattice-mismatched GaAs substrates in order to examine various material properties which may be utilized advantageously for certain devices. The emphasis has been placed on the development of a heterojunction insulated-gate field effect transistor (HIGFET) using lattice-mismatched InGaAs and InA1 As layers to demonstrate the effective utilization and advantages of strained layers. |
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| Research on Materials and Components for Opto-Electronics Signal Processing and Computing |
30 JUN 90 |
19 pages |
| Authors:
William S. Chang; Shigeru Niki; Albert L. Kellner; H. H. Wieder; CALIFORNIA UNIV SAN DIEGO LA JOLLA DEPT OF ELECTRICAL AND COMPUTER ENGINEERIN G
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| This project is a continuation of the project (AFOSR 84-0389) under the same title 'Research on Materials and Components for Opto-Electronic Signal Processing and Computing.' for the period Oct. 1st, 1984 to Nov. 30th, 1988. Recognizing both the importance of spatial light modulators (SLM) to opto- electronic computing and signal processing and the unique material properties of multiple quantum well (MQM) structures, we have focused our investigation on the electro-optical ... |
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| Field-Effect Spectroscopy of Interface States |
31 DEC 88 |
79 pages |
| Authors:
H. H. Wieder; CALIFORNIA UNIV SAN DIEGO LA JOLLA DEPT OF ELECTRICAL AND COMPUTER ENGINEERIN G
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| During the past year our research has been concerned principally with the synthesis by MBE of InxAl(1-x)As/InP heterojunctions in strained layer structures (SLS). Some of the layers were grown with their lattice constants matched to that of their (100)-oriented InP substrates. Others were chosen deliberately to be in compression or in tension and with appropriate combinations of their fractional indium concentration, x, and thickness, d, were intended to be strained ... |
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| Research on Materials and Components for Opto-Electronic Signal Processing and Computing |
28 SEP 87 |
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| Authors:
William S. Chang; Shigern Nikki; Timothy Van Eck; H. H. Wieder; Andrew Williams; CALIFORNIA UNIV SAN DIEGO LA JOLLA
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 | Electro-absorption and electro-refraction properties of strained multiple quantum-well structures (QW) in In(x)Ga(1-x)As/GaAs were investigated for spatial modulation applications. A new technique that will allow us to obtain large number of quantum well periods and large depth of modulation has been developed. Optical-optical interaction of a modulator-detector diode pair made form such QW structure had been demonstrated. Optimization of QW structure design has been investigated. Keywords include: III-V Compound Semiconductors, Electro-absorption, ... |
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| SIMPLE, INEXPENSIVE DOUBLE AC HALL MEASUREMENT SYSTEM FOR ROUTINE SEMICONDUCTOR CHARACTERIZATION |
SEP 87 |
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| Authors:
Peter Chu; Shigeru Niki; J. W. Roach; H. H. Wieder
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| a simple, comparatively inexpensive hall-effect measurement apparatus is described in which the magnetic field and sample current are sine waves at different frequencies. the current for the electromagnet is obtained directly from the 60-hz power line, providing magnetic fields approximately equal to 0.1 t(rms). the sample current frequency is 200 hz and the hall voltage is detected at the sum frequency, 260 hz, by a lock-in amplifier. such double ac ... |
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| Research on Materials and Components for Opto-Electronic Signal Processing and Computing |
30 DEC 86 |
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| Authors:
William S. Chang; Albert L. Keller; C. C. Sun; Timothy Van Eck; H. H. Wieder; CALIFORNIA UNIV SAN DIEGO LA JOLLA
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| Electro-absorption and electro-refraction properties of heterostructures and multiple quantum-well structures in III-V semiconductors were investigated for spatial modulation applications. A new device, the gate controlled photo-diode (GCPD) has been conceived and demonstrated. It has potential applications in optical signal processing. Keywords include: III-V compound Semiconductors, Electro-absorption, Electro-refraction, Gate Controlled Photodiode, and Quantum Wells. |
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| Research on Materials and Components for Opto-Electronic Signal Processing |
26 DEC 85 |
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| Authors:
William S. Chang; Albert L. Kellner; Timothy Van Eck; L. M. Walpita; H. H. Wieder; CALIFORNIA UNIV SAN DIEGO LA JOLLA DEPT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCES
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| Electroasbsorption and electrorefraction properties of heterostructures and multiple quantum-well structures in III-V semiconductors were investigated for spatial modulation and optical fibercommunication applications. Optical waveguides are fabricated and evaluated. A new device, the gate controlled photo diode (GCPD) has been conceived and demonstrated. It has potential applications in optical signal processing. Keywords: III-V Compound semiconductros; Electroabsorption; Electrorefraction; and Gated photo diode. |
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| Surface and Interfacial Properties of InP |
30 APR 85 |
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| Authors:
L. G. Meiners; H. H. Wieder; CALIFORNIA UNIV SAN DIEGO LA JOLLA DEPT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCES
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| Calculations of the effect of bulk traps on the time dependence of the channel current in InP accumulation-type MISFET's are reported. It is shown that a uniform density of deep acceptors in the bulk material given rise to a decay in the channel current which decays approximately linearly as a function of the logarithm of time. If capture of the electrons is assumed to occur by a nonradiative multiphonon emission ... |
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| Molecular Beam Epitaxy for Combined Optical and Electronic Circuits |
24 DEC 84 |
4 pages |
| Authors:
H. H. Wieder; CALIFORNIA UNIV SAN DIEGO LA JOLLA DEPT OF ELECTRICAL ENGINEERING AND COMPUTE R SCIENCES
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| This is a final report on the purchase and installation of a Molecular Beam Epitaxial (MBE) Deposition Machine. Additional funds were provided by the National Science Foundation, by USCD intramural contributions and by the Powell (private) foundation for a total of $471,000. The machine presently in operation is a modified Varian Associates Gen.II Machine without the low energy electron diffraction and without the Auger surface spectrometer. (RRH) |
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| Surface and Interfacial Properties of Ga(0.47)In(0.53)As Alloys |
25 OCT 1984 |
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| Authors:
H. H. Wieder; CALIFORNIA UNIV SAN DIEGO LA JOLLA DEPT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCES
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| Semiconducting Ga0.47In0.53As layers whose lattice constants match that of semi-insulating InP are, potentially, useful for discrete and integrated circuit microwave transistors and opto-electronic sensors compatible with the low loss, low dispersion spectral window of optical fibers. Their implementation requires evaluation, modelling and interpretation of the surface and interfacial properties of this ternary semiconducting compound in terms of fundamental physical parameters. We have investigated by means of field effect-controlled galvanomagnetic measurements ... |
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| Characterization of Surface Electronic Properties of Semi-Insulating InP |
26 SEP 1984 |
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| Authors:
H. H. Wieder; CALIFORNIA UNIV SAN DIEGO LA JOLLA DEPT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCES
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| The surface and interfacial charge carrier transport properties of semiinsulating InP have been investigated. It is shown that space charge limited current flow in the presence of trapping in conjunction with charge transport in the accumulation layer are present in two-terminal and three-terminal InP structures. Additional originator-supplied keywords include: Surface and Interfacial Properties, and III-V Compound Semiconductors. |
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| Process for Making a Heterojunction Source-Drain Insulated Gate Field-Effect Transistors Utilizing Diffusion to Form the Lattice. |
04 SEP 1984 |
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| Authors:
H. H. Wieder; A. R. Clawson; DEPARTMENT OF THE NAVY WASHINGTON DC
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| An apparatus for and a method of making heterojunction source-drain insulated gate field-effect transistors in order to obtain higher gain-bandwidth products at microwave frequencies. A semi-insulating InP semiconductor substrate is provided with a ternary alloy layer of p-type Ga0.47In0.53As, or optionally, an acceptor-doped p-type bulk of Ga0.47In0.53As can be substituted. Troughs are shaped in the substrate and layer for receiving a material lattice-matched to the n+ p-type Ga0.47In0.53As to perform ... |
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| Heterojunction-Diode Transistor EBS Amplifier. |
18 OCT 1983 |
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| Authors:
H. H. Wieder; DEPARTMENT OF THE NAVY WASHINGTON DC
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| An improved apparatus modulates greater currents at higher frequencies over extended bandwidths. In addition to conventional biasing and modulation a beam of electrons is directed onto a heterojunction-diode device disposed to receive the modulating electron beam. The heterojunction diode device is fabricated from two different semiconducting materials having identical crystalline lattice structures, different fundamental energy bandgaps and different impurity types of different concentrations. This combination of properties assures greater output ... |
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| Accumulation-Mode in O.53 Ga 0.47 as Field Effect Transistor. |
03 OCT 1983 |
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| Authors:
D. Mullin; H. H. Wieder; DEPARTMENT OF THE NAVY WASHINGTON DC
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| The invention is a normally-off, accumulation mode field-effect-transistor (FET) utilizing a positive bias on an insulated gate to induce a conducting channel between source and drain ohmic contacts. The device is fabricated on an epitaxial layer of semi-insulating In(0.53)Ga(0.47)As. The semi-insulating layer of In(0.53)Ga(0.47)As is epitaxially deposited upon a semi-insulating InP substrate. Ohmic source and drain contacts are formed at separate regions upon the free surface of the semi-insulating In(0.53)Ga(0.47)As ... |
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| Surface and Interfacial Properties of Ga(0.47)In(0.53)As Alloys |
26 JUL 1983 |
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| Authors:
H. H. Wieder; CALIFORNIA UNIV SAN DIEGO LA JOLLA DEPT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCES
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| High frequency C-V measurements and quasi-static gate-controlled galvanomagnetic measurements have confirmed theoretical predictions that the surface Fermi level of Ga0.47In0.53As is pinned by lattice defect-related surface states at approximately 0.55 eV above the valence band edge. The total dnesity of the donor and acceptor centers, related to these defects, is two to three orders smaller than those of InP and the respective barrier heights of n and p-type Ga0.47In0.53As-metal contacts ... |
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| Ion-Beam Milling of Silicon Carbide Epitaxial Layers |
04 AUG 1982 |
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| Authors:
H. H. Wieder; CALIFORNIA UNIV SAN DEIGO LA JOLLA DEPT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCES
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| Ion milling of photolithographically processed silicon carbide heteroepitaxially grown layers on Si is feasible using an aluminum mask which is produced by standard photolithographic procedures and techniques. (Author) |
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| Magnetoresistance Mobility Profiling of MESFET Channels. |
APR 1980 |
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| Authors:
J. R. Sites; H. H. Wieder; COLORADO STATE UNIV FORT COLLINS DEPT OF PHYSICS
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| Magnetoresistance provides a straightforward, non-destructive technique for determining the carrier mobility in the conducting channel of field effect transistors (FETs) over their full range of operation. The analysis is well suited to the typical FET geometry. The technique is illustrated here by a comparative study of GaAs depletion mode FET devices. (Author) |
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| Electronic Profile of n-InAs on Semi-Insulating GaAs. |
20 OCT 1978 |
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| Authors:
H. A. Washburn; J. R. Sites; H. H. Wieder; COLORADO STATE UNIV FORT COLLINS DEPT OF PHYSICS
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| Electron density and mobility are measured in three regions of InAs epilayers on GaAs substrate: (1) The interfacial layer shows an increase in density and decrease in mobility over a 3 micron distance; (2) the bulk of the epilayer has n approx. 1/10 to the 16th power cc, mu approx. 100000 sq. cm/V-sec; (3) the front surface, accumulated at zero bias, displays surface quantization effects and an enhanced effective mass. ... |
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| BIBLIOGRAPHY ON THE HALL EFFECT THEORY, DESIGN, AND APPLICATIONS, |
15 SEP 1963 |
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| Authors:
A. R. Clawson; L. E. Leonard; H. H. Wieder; NAVAL ORDNANCE LAB CORONA CALIF
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| Supplement 1 to NAVWEPS Report 7233, 'Bibliography on the Hall Effect Theory, Design and Applications', continues the international survey of unclassified scientific papers and patents on research and development of the Hall effect, and on electronic devices based on the Hall effect, to 1 July 1963. This is the first of a series of annual supplements, designed to extend the usefulness of the basic document. (Author) |
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| HALL EFFECT INVESTIGATIONS. |
15 SEP 1963 |
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| Authors:
H. H. Wieder; A. R. Clawson; NAVAL ORDNANCE LAB CORONA CALIF
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| Thin films of indium antimonide vapordeposited on oxide-coated surfaces of aluminum or tantalum offer an advantage in the fabrication of thin film Hall generators because of the superior thermal conductance between the film and substrate. The deposition and recrystallization of InSb films on oxidemetal substrates have been investigated in detail. Additional studies on the magnetic circuit associated with Hall generators are described and the flux concentrator problem is treated empirically. ... |
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Reports by Author
