US Government As Represented by the Secretary of the Army

Other

Robert A Lux

James F Harvey

Raphael Tsu

Stanley Kronenberg

Arthur C Paolella

Dana J Sturzebecher

Thomas P Higgins

Arthur Tauber

Maurice Weiner

Thomas E Koscica

Steven C Tidrow

Robert J Zeto

Terence Burke

Lawrence E Kingsley

Louis C Poli

Hardev Singh

Charles D Mulford, Jr

James A Harvey

Ravi Khanna

Clarence G Thornton

A solid state electronic device exhibiting negative differential resistance is fabricated by depositing a thin layer of amorphous silicon on a single crystal substrate, doped N,. The amorphous silicon is simultaneously crystallized and oxidized in a dry N,and O,mixture. The result is a layer of amorphous SiO,surrounding microclusters of crystalline silicon. A layer of polycrystalline silicon is deposited to a thickness of approximately 0.5 micron. Ohmic metal contacts are made to the top and bottom. These active layers are isolated by insulating SiO,. A bias voltage applied between the metal contacts results in negative differential resistance due to tunneling through resonant energy levels in microclusters.

Negative differential resistance device based on tunneling through microclusters, and method therefor

A solid state electronic device exhibiting negative differential resistance s fabricated by depositing a thin layer of amorphous silicon on a single crystal substrate, doped N.sup.+. The amorphous silicon is simultaneously crystallized and oxidized in a dry N.sub.2 and O.sub.2 mixture. The result is a layer of amorphous Sio.sub.2 surrounding microclusters of crystalline silicon. A layer of polycrystalline silicon is deposited to a thickness of approximately 0.5 micron. Ohmic metal contacts are made to the top and bottom. These active layers are isolated by insulating SiO.sub.2. A bias voltage applied between the metal contacts results in negative differential resistance due to tunneling through resonant energy levels in microclusters.

Negative differential resistance device based on tunneling through

The invention provides light sources which are easily compatible with standard silicon VLSI processing and can be located directly in the material of the silicon VLSI chip. P-type silicon substrate is processed to produce proturbances, the proturbances preferably having tip dimensions on the order of 5-10 mm. A native oxide film (SiO.sub.2) is caused to develop on the surface of the silicon substrate. A thin, transparent, conductive film is then deposited on top of the SiO.sub.2. Electrical contacts are made to the top of the conductive film and to the bottom of the silicon substrate. The carriers for electroluminescence are supplied by the P-doped silicon substrate (holes) and the conductive film (electrons). When a voltage is applied across the layers via the electrical contacts, the holes are concentrated in the region of the tip of the proturbances because the electric field lines concentrate near a pointed object, and electron current across the SiO.sub.2 barrier in response to the voltage drop will be largest in the vicinity of the tip because the SiO.sub.2 barrier is thinnest there, resulting in strong visible luminescence.

Silicon nanostructure light-emitting diode

An ablation process by which fused deposits of silicon particles are accuated on a substrate of selected material in accordance with whether microclusters of spherical configurations or microfilaments of cylindrical configurations are to be fabricated. Silicon ablation is accomplished in an inert gas atmosphere with an excimer laser that generates light pulses of which the wavelength and frequency are controlled to fix the energy level thereof. The pressure of the inert gas atmosphere is also controlled in accordance with whether microclusters or microfilaments are to be fabricated.

Fabrication of silicon microclusters and microfilaments

A quantum interference device in the form of a variable lateral confinement resonant tunneling transistor having a quantum waveguide structure including a primary current transmission path defined by a region between source and drain electrodes and where there is a resonance region therebetween in which quantum interference of tunneling wave functions establish a resonance tunneling condition that extends beyond the primary current path. Upon the application of a voltage across the drain and source electrodes, a tunneling current can be made to flow. A gate electrode formed on the quantum well structure remote from the primary current transmission path includes a variable depletion region thereunder or an electrostatic pinch off region, the size of which is a function of the magnitude of the bias voltage applied thereto. The size of the depletion region or the pinch off region affects the dimensions of the resonance region and accordingly the current flow between the source and drain electrodes as a result of a change in the energy and momentum conditions for resonance tunneling.

Variable lateral quantum confinement transistor

A pyramid shaped etch is made in an n or p type silicon substrate, or any symmetric etch with slanted edges, with p or n type implants in the slanted edges of the etch to form a PN junction. On this structure, an emitter and two collectors are formed by further implanting n+ regions in the PN junction region. To complete the device, ohmic contacts are formed to establish a base region. In operation, an appropriate bias is applied to the emitter through to the base and collectors. By so biasing the device, the device operates as a standard bipolar transistor. The currents of both the minority and majority carriers in the base region will respond to the component of the magnetic field perpendicular to the face of the slanted etch. As a result, there will be a difference in the currents in the collectors. These currents can then be simply calibrated to measure the magnetic field component. By forming similar sensors on 3 or 4 of the faces of the etched structure all three components of the magnetic field can be computed.

Microelectronic 3D bipolar magnetotransistor magnetometer

One or more double barrier resonant tunneling filters are provided for electron propagation mode control in nanostructure quantum wire electron waveguides and in quantum interference devices in the waveguide.

Double barrier resonant propagation filter

A microwave oscillator capable of being switched into or out of the oscillating state within a fraction of the period of oscillation. The instant-on microwave oscillator permits both the generation and modulation of a microwave signal by using a single active microwave semiconductor device which is a resonant tunneling diode. The instant-on microwave oscillator circuit includes a conductive transmission line having an impedance Z.sub.O with a corresponding ground plane; and a pair of output terminals connected one on each of the transmission line and the ground plane. An impedance Z.sub.L, having an impedance value which is less than ZO, is positioned across the output terminals. A pair of input terminals is connected at the opposite end of the transmission line, one on each of the transmission line and the ground plane with a resonant tunneling diode connected across the input terminals. An impedance Z is connected to the input terminal on the biased side of the transmission line. Means are provided for applying a square wave shaped switched power supply signal to the resonant tunneling diode through impedance Z. Means are also provided for separating the square wave and oscillation signals at the output terminals.

Instant-on microwave oscillators using resonant tunneling diode

The present invention describes a method of explosively vaporizing a piece f semiconductor material in a plasma formed by a fast, high voltage current pulse. The semiconductor material may be formed from crystalline, polycrystalline, or amorphous forms of semiconductor material. After the semiconductor material is vaporized, it coalesces as the plasma begins to cool and is deposited in a collection system. The size and composition of the microparticles formed by this process can be controlled by conditioning the plasma in predetermined manners. In particular, impurities can be introduced either in the target material, in gas introduced in the plasma, or in the gas through which the coalescing microparticles travel prior to deposition.

Fabrication technique for silicon microclusters using pulsed electrical

An optically controlled resonant tunnel diode oscillator assembly having a esonant tunnel diode (RTD) which, when voltage biased, oscillates at a free running frequency; an optical signal delivery system, such as a light intensity modulator connected to optical fibers; and other oscillator circuitry which one skilled in the art could readily adapt to the concepts of the present invention. In operation, the free running oscillation of the RTD can be frequency modulated or can be intensity locked to the intensity modulated optical signal delivered via the optical signal delivery system.

Optically controlled resonant tunnel diode oscillator

An optically injection locked resonant tunnel diode oscillator assembly hng a resonant tunnel diode (RTD) which, when voltage biased, oscillates at a free running frequency; an optical signal delivery system, such as a light intensity modulator connected to optical fibers; and other oscillator circuitry which one skilled in the art could readily adapt to the concepts of the present invention. In operation, the free running oscillation of the RTD can be locked to the phase and frequency of the intensity modulated optical signal delivered via the optical signal delivery system. This injection locking occurs as the modulation frequency approaches the free running oscillation frequency.

Optically injection locked resonant tunnel diode oscillator

The surface leakage on a III-V semiconductor is reduced by selectively grng a mixed oxide on the surface of the semiconductor to passivate the semiconductor and reduce the surface leakage.

Method of reducing the surface leakage on a III-V semiconductor

This circuit comprises a solid state crystal radiation counter having its plified output connected in parallel to a pair of pulse height discriminators with thresholds of V.sub.1 and 2V.sub.1 volts, wherein V.sub.1 is above the counter noise level. A pair of pulse counters are arranged to count the outputs of the discriminators and a processor circuit is connected to the pulse counter outputs and is arranged to calculate the quotient of the square of the output of the pulse counter connected to the discriminator with the lower threshold and the output of the other pulse counter. A display circuit is arranged to provide a reading related to the output of the processor circuit.

Solid state nuclear radiation detector circuit with constant sensitivity

A quartz fiber electroscope shunted by a variable capacitor is periodically coupled to a radiation detection capacitor formed of material of a relatively large atomic number, e.g. aluminum, completely surrounded by a material of lesser atomic number, e.g. polyethylene. An electrical charge is induced by neutron or gamma radiation on the material of relatively large atomic number which charge is then coupled to the electroscope and variable capacitor combination. The variable capacitor is set at its maximum when the voltage is transferred from the detection capacitor. The variable capacitor is then reduced, thus raising the voltage on the electroscope with the dose being determined by the reduction in capacitance necessary to raise the indicated electrometer voltage to a predetermined magnitude. The variable capacitor includes indicia thereon which is calibrated such that the voltage change provides a direct reading of the charge transfer and consequently dosage.

Growing community of inventors

Toms River, NJ, United States of America

Robert A Lux