Patents by Inventor Richard F. Greene

Richard F. Greene has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5698942
    Abstract: A field emitter flat panel display and associated method of operation provides an electron emission path along which a beam of electrons emitted by a microelectronic field emitter travels such that the electrons impinge upon a light emitting element without passing through a mirror. The light emitting element is spaced apart from the microelectronic field emitter and includes a mirror and a luminescence layer on the mirror. The flat panel display can also include a deflector, such as a deflector electrode, which is spaced apart from both the microelectronic field emitter and the associated light emitting element and which controllably deflects the beam of electrons emitted by the microelectronic field emitter toward the luminescent layer of the associated light emitting element and along a curved electron emission path which is independent of the underlying mirror.
    Type: Grant
    Filed: July 22, 1996
    Date of Patent: December 16, 1997
    Assignee: University of North Carolina
    Inventors: Richard F. Greene, Stephen M. Bobbio, Farid M. Tranjan, Kasra Daneshvar, Thomas D. DuBois
  • Patent number: 5216359
    Abstract: Internal test sites on integrated circuit chips may be tested with minimal input/output pad or chip area overhead by providing transient interconnections to the internal test sites using an optically activated photoconductive layer which is formed over the active device layers of the integrated circuit to be tested. The photoconductive layer may be optically activated using an optical mask or hologram, to electrically access the desired internal test sites. Different test sites may be tested using different masks or holograms. The photoconductive layer is preferably hydrogenated amorphous silicon which is highly compatible with standard integrated circuit processing.
    Type: Grant
    Filed: January 18, 1991
    Date of Patent: June 1, 1993
    Assignee: University of North Carolina
    Inventors: Rafic Z. Makki, Kasra Daneshvar, Farid M. Tranjan, Richard F. Greene
  • Patent number: 5171608
    Abstract: Method for improved photolithography using a laser induced metallization cess to produce a metal mask wherein a work piece surface is treated to have a predetermined pattern of at least two materials each having different electron band gaps, the treated work piece is positioned in a metallizing solution, and the workpiece is exposed to a laser beam having a wavelength corresponding to the electron gap of a selected one of the materials. The method can advantageously be used to produce ohmic contacts for microcircuit devices.
    Type: Grant
    Filed: September 28, 1990
    Date of Patent: December 15, 1992
    Assignee: The Unites States of America as represented by the Secretary of the Navy
    Inventors: Richard F. Greene, Joseph Zahavi, Pehr E. Pehrsson, Christie R. Marrian
  • Patent number: 5150192
    Abstract: A field emitter structure is disclosed which comprises: a substrate selec from the group consisting of a semi-insulating substrate and an insulating substrate, the substrate having first and second surfaces and at least one hole therethrough; a first conducting layer disposed on the first surface of the substrate and having at least one aperture aligned with an associated at least one hole in the substrate, the at least one aperture of the first conducting layer comprising an extraction electrode; and a second conducting layer disposed on the second surface and projecting into the at least one hole in the substrate and into the at least one associated aperture of the first conducting layer and forming at least one associated apex inside the at least one hole, the at least one associated apex comprising an associated electron field emitter.
    Type: Grant
    Filed: June 20, 1991
    Date of Patent: September 22, 1992
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Richard F. Greene, Henry F. Gray
  • Patent number: 5057047
    Abstract: A method for fabricating field emitter arrays is disclosed which uses a substrate as both an emitter tip mold and an insulating layer. A thick single crystal substrate is orientation-dependent-etched on one side to form a plurality of holes having crystallographically sharp apices or a non-crystalline substrate is etched on one side to form a plurality of holes with a high depth-to-width ratio. An emitter layer is deposited on the substrate surface and in the plurality of holes. The remainder of the field emitter array structure is then formed on the opposite side of the substrate using conventional deposition and etching techniques. Once the emitter is formed, the remaining fabrication steps are self-aligning. The field emitter array thus formed exhibits high input impedance at high frequency, making the field emitter array suitable for high frequency uses.
    Type: Grant
    Filed: September 27, 1990
    Date of Patent: October 15, 1991
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Richard F. Greene, Henry F. Gray
  • Patent number: 4987377
    Abstract: Distributed amplifiers in integrated circuit form wherein dielectric matel and electrically conductive material combine to form field emitter cathodes, grids, and anodes in a module forming one or more amplifier cells embedded in a matrix of reactive impedances that form companion stripline-like transmission lines in a vacuum or sufficiently low pressure gas such that electrons remain unscattered during travel over trajectories from cathode to anode in a cell.
    Type: Grant
    Filed: October 31, 1989
    Date of Patent: January 22, 1991
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Henry F. Gray, Richard F. Greene
  • Patent number: 4901028
    Abstract: Distributed amplifiers in integrated circuit form wherein dielectric material and electrically conductive material combine to form field emitter cathodes, grids, and anodes in a module forming one or more amplifier cells embedded in a matrix of reactive impedances that form companion stripline-like transmission lines in a vacuum or sufficiently low pressure gas such that electrons remain unscattered during travel over trajectories from cathode to anode in a cell.
    Type: Grant
    Filed: March 22, 1988
    Date of Patent: February 13, 1990
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Henry F. Gray, Richard F. Greene
  • Patent number: 4843060
    Abstract: A method for growing a patterned superconductive oxide film of the general formula XZ.sub.2 Cu.sub.3 O.sub.6+x is disclosed, wherein X is yttrium, a lanthanide or a mixture thereof, Z is one or more alkaline earth elements and x is a number between 0 and 1. This patterned superconductive oxide film of XZ.sub.2 Cu.sub.3 O.sub.6+x is formed by preparing an aqueous solutuion of the nitrates of X, Z and Cu in the X:Z:Cu stoichiometric ratio of 1:2:3; spraying the aqueous nitrate solution onto a heated substrate to form on the substrate a thin film of XZ.sub.2 Cu.sub.3 O.sub.y material, wherein y is an undefined number; spot-heating preselected portions of the thin film in an oxygen-rich atmosphere to convert the preselected portions into the patterned superconductive oxide film of XZ.sub.2 Cu.sub.3 O.sub.6+x ; and removing the unheated thin film of XZ.sub.2 Cu.sub.3 O.sub.y material with a solvent.
    Type: Grant
    Filed: November 23, 1987
    Date of Patent: June 27, 1989
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Howard Lessoff, Richard F. Greene
  • Patent number: 4745326
    Abstract: A controlled porosity dispenser cathode and method of manufacture therefo using chemical vapor deposition and laser drilling, ion milling, or electron discharge machining for consistent and economical manufacturing a cathode with pores on the order of 0.2 to 2 .mu.m in diameter.
    Type: Grant
    Filed: December 10, 1986
    Date of Patent: May 17, 1988
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Richard F. Greene, Richard E. Thomas
  • Patent number: 4578614
    Abstract: A field-emitter switching device wherein a positive pulse is applied to a te (which is held at a bias potential V.sub.1 just below turn-on). A collector is held at a potential higher than the gate in order to collect emitted electrons from a field emitter source. As the voltage is applied to the gate, electrons are emitted immediately from the source and travel to the most positive potential at the collector. Because of the field emitter geometry, such electron transport is extremely fast. The ultra-fast switching speed is attained because the electrons reach near-maximum velocity within a few field tip diameters of the source.
    Type: Grant
    Filed: July 23, 1982
    Date of Patent: March 25, 1986
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Henry F. Gray, Richard F. Greene
  • Patent number: 4513308
    Abstract: A Field Emitter Array comprising a semiconductor substrate with an emitter urface formed thereon. A plurality of emitter pyramids is disposed on the emitter surface for emitting an electron current. The magnitude of the electron current emitted by each emitter pyramid I.sub.max, is controlled by a reverse-biased p-n junction associated with each emitter pyramid where I.sub.max =j.sub.sat X A.sub.p-n, j.sub.sat being the saturation current density and A.sub.p-n being the area of the reverse-biased p-n junction associated with each emitter pyramid. A grid, positively biased relative to the emitter surface and the emitter pyramids, is disposed above the emitter surface for creating an electric field that induces the emission of the electron current from the emitter tips.
    Type: Grant
    Filed: September 23, 1982
    Date of Patent: April 23, 1985
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Richard F. Greene, Henry F. Gray
  • Patent number: 4499481
    Abstract: An FET with an extremely short channel formed by the apex of a substrate ridge structure protruding upward through the channel layer toward a Schottky-barrier gate contact. The device is formed by etching a modulation-doped substrate to form an upwardly protruding ridge with the apex modulation-doped. A semiconductor layer is then disposed over the substrate surface with the protruding ridge to obtain an epitaxial interface therebetween. Source and drain regions are doped into the semiconductor layer on opposite sides of the ridge structure. Finally, ohmic contacts are formed on the semiconductor layer over the source and drain regions and a Schottky-barrier metalization is deposited on the semiconductor layer above the ridge structure. This device has a very short channel, a low transit time, a low gate capacitance, and an enhanced transconductance.
    Type: Grant
    Filed: September 14, 1983
    Date of Patent: February 12, 1985
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Richard F. Greene
  • Patent number: 4379979
    Abstract: A controlled porosity sheet defining a surface for a thermionic dispenser thode and a method of manufacture. Starting with a generally flat silicon template substrate structure having an array of upstanding microposts 1-25 microns across on 5-100 micron spacings from each other, a layer of metal is deposited on the substrate to surround the microposts and cover the substrate structure to a desired depth. The metal layer is then abraded to a smooth, flat surface which exposes the microposts. Thereafter, the silicon substrate and microposts are completely etched away, leaving a metal sheet having micron-size holes therethrough.
    Type: Grant
    Filed: February 6, 1981
    Date of Patent: April 12, 1983
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Richard E. Thomas, Richard F. Greene
  • Patent number: 4371809
    Abstract: In a controlled-porosity dispenser cathode of the type which has a foil w a plurality of holes covering the emitting material so that emitting material is dispensed through the holes to the electron-emitting surface of the foil and electrons are actually emitted through the holes and a small area surrounding each hole, a non-emitting shadow grid is laid down on the surface of the foil in such a configuration that it does not obstruct any of the emitting holes, has the same shape as the control grid, and is substantially in precise registration with the control grid.
    Type: Grant
    Filed: June 19, 1980
    Date of Patent: February 1, 1983
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Richard E. Thomas, George A. Haas, Richard F. Greene
  • Patent number: 4307507
    Abstract: A method of manufacturing a field-emitter array cathode structure in which substrate of single crystal material is selectively masked such that the unmasked areas define islands on the underlying substrate. The single crystal material under the unmasked areas is orientation-dependent etched to form an array of holes whose sides intersect at a crystallographically sharp point. Following removal of the mask, the substrate is covered with a thick layer of material capable of emitting electrons which extends above the substrate surface and fills the holes. Thereafter, the material of the substrate underneath the layer of electron-emitting material is etched to expose a plurality of sharp field-emitter tips.
    Type: Grant
    Filed: September 10, 1980
    Date of Patent: December 29, 1981
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Henry F. Gray, Richard F. Greene
  • Patent number: 4254357
    Abstract: A multi-arrayed electron emitter for microwave tubes in which the emitting urface is an array of continually replenished low-work-function regions, (micro-patches), whose boundaries include a control grid which is integral with the cathode surface and which controls emission from the low-work-function micro-patches. The continually replenished low-work-function regions are uniformly positioned relative to a matrix of uniformly spaced openings through which the low-work-function material is released.
    Type: Grant
    Filed: September 14, 1979
    Date of Patent: March 3, 1981
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: George A. Haas, Richard E. Thomas, Richard F. Greene
  • Patent number: 4224520
    Abstract: An amorphous film (44) of a photoresponsive semi-conducting material such germanium-telluride deposited upon a thick silicon dioxide layer (40) formed on a silicon chip substrate (38). The silicon chip (38) underlying the central region of the amorphous film (44) is etched through to the silicon dioxide layer (40) to define a trough (48) thermally isolating the central region of the silicon dioxide layer (40).
    Type: Grant
    Filed: July 13, 1979
    Date of Patent: September 23, 1980
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Richard F. Greene, Kurt P. Scharnhorst
  • Patent number: 4147515
    Abstract: An electro-chemical gas sensor for use in electron tubes comprising a crylline body of BaO formed on a non-interacting (chemically and electrically) substrate and at least two electrodes. The change in conductivity of the barium oxide upon exposure to tube gases may be used to determine the type and quantity of gases contaminating the electron emitter and estimate changes in the emitter's work function or electron emission capability due to gas contamination.
    Type: Grant
    Filed: December 22, 1977
    Date of Patent: April 3, 1979
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: George A. Haas, Richard F. Greene, Arnold Shih