Search Patents
  • Surface planarization of high temperature superconductors
    Patent number: 6251835
    Abstract: Planarizing High Temperature Superconductor (HTS) surfaces, especially HTS thin film surfaces is crucial for HTS thin film device processing. Disclosed is a method of surface planarization for HTS film. The method includes first smoothing the HTS surface by Gas Cluster Ion Beam bombardment, followed by annealing in partial pressure of oxygen to regrow the damaged surface layer. A rough HTS surface can be planarized down to a smoothness with a standard deviation of one nanometer or better.
    Type: Grant
    Filed: May 6, 1998
    Date of Patent: June 26, 2001
    Assignee: Epion Corporation
    Inventors: Wei-Kan Chu, Judy Z. Wu
  • Vibration-free levitated platform
    Patent number: 5726512
    Abstract: An isolation system for isolating a first object from vibrations from a second object. Such vibrations will have three orthogonal components, one oriented along a line between the objects, and two oriented 90.degree. apart in a plane normal to that line. The system includes three superconductor/magnet stages, each stage designed to extinguish one of the orthogonal components.
    Type: Grant
    Filed: October 4, 1996
    Date of Patent: March 10, 1998
    Assignee: The University of Houston System
    Inventors: Wei-Kan Chu, Quark Yung-Sung Chen, Ki-Bui Ma, Mark Alan Lamb, Chase Kenyon McMichael, Ignatius S. T. Tsong
  • Method for manufacture of ultra-thin film capacitor
    Patent number: 4333808
    Abstract: A suitable substrate is provided to which is applied a metal electrically conductive film electrode. The substrate and electrically conductive electrode film are then exposed to ion beam implantation of O+ or N+ ions to impregnate the surface of the metal electrode with O+ or N+ ions. Thereafter, the substrate and electrically conductive film having implanted O+ or N+ ions is annealed so as to stabilize the oxide structure which has been implanted into the surface of the electrically conductive film to provide an ultra-thin dielectric film.
    Type: Grant
    Filed: February 13, 1981
    Date of Patent: June 8, 1982
    Assignee: International Business Machines Corporation
    Inventors: Arup Bhattacharyya, Wei-Kan Chu, James K. Howard, Francis W. Wiedman
  • Magnet-superconductor flywheel and levitation systems
    Patent number: 5831362
    Abstract: Disclosed is a flywheel system for storing kinetic energy which utilizes a high temperature superconductor/magnet system for the flywheel bearings. The flywheel includes a first magnet, and having a ring magnet defining an opening. The levitation system includes a magnet for attractively interacting with first flywheel magnet, with a high temperature superconductor interposed between them, and further includes a magnet system for repulsively interacting with and partially inserted into the ring magnet.
    Type: Grant
    Filed: July 16, 1997
    Date of Patent: November 3, 1998
    Assignee: The University of Houston
    Inventors: Wei-Kan Chu, Quark Yung-Sung Chen, Ki-Bui Ma, Harold Zule Xia, Mark Alan Lamb, Rodger Sheldon Cooley, Chase Kenyon McMichael
  • Satellite angular momentum control system using magnet-superconductor flywheels
    Patent number: 6231011
    Abstract: A torque/reactive momentum wheel control system for use in satellites for dynamic attitude maintenance and alteration where the flywheel of each momentum wheel is levitated by a high-temperature superconducting element repulsively interacting with permanent magnets in the flywheel. The spin rate (rpm) of the flywheel being controlled by either an active magneto or electromagneto drive system. Each momentum wheel is cooled by a cryo-cooler and can have a total weight of about 10 Kg to a fraction of 1 Kg and delivering 3.5 Js with less than 1 W loss.
    Type: Grant
    Filed: November 2, 1998
    Date of Patent: May 15, 2001
    Assignee: University of Houston System
    Inventors: Wei-Kan Chu, Ki Bui Ma, Jang-Horng Yu, Quark Yung-Sung Chen, Eujeong Lee, Yevgeniy Postrekhin
  • Method of forming a nonsilicon semiconductor on insulator structure
    Patent number: 4891329
    Abstract: A method of forming a nonsilicon semiconductor layer on an insulating layer by forming a thin heteroepitaxial layer of nonsilicon semiconductor on a first substrate having a lattice structure which matches that of the heteroepitaxial layer. A first insulating layer is formed on the heteroepitaxial layer. A second insulating layer is formed on the surface of a second substrate. The first and second insulating layers are bonded together to form a unified structure, and the first substate is etched away. In a preferred embodiment the heteroepitaxial layer is germanium, gallium arsenide or silicon-germanium alloy while the first substrate is silicon, germanium, gallium arsenide or silicon-germanium alloy.
    Type: Grant
    Filed: November 29, 1988
    Date of Patent: January 2, 1990
    Assignees: University of North Carolina, Microelectronics Center of North Carolina
    Inventors: Arnold Reisman, Wei-Kan Chu
  • High temperature superconducting magnetic bearings
    Patent number: 5177387
    Abstract: A magnetic bearing having a rotatable member and a stationary member on one of which is mounted a superconductor while on the other is mounted a set of permanent magnets or electromagnets arranged as a quadrupole or multiple dipoles. The magnetic member, which is in the form of a dipole, a quadrupole, or other multiple dipole, such as an octopole, is positioned to enable the magnetic fields generated by the permanent magnets to interact with the superconducting material and to confine the shaft in all directions in the desired location. The bearing systems can be used as either a thrust bearing or as a journal bearing, or as both. Each dipole may be twinned to reduce magnetic field asymmetry and reduce energy dissipation upon rotation. The superconductor may be laminated, and/or additional magnets may be located outside the superconductor in order to increase the bearing stiffness and rigidity.
    Type: Grant
    Filed: December 4, 1990
    Date of Patent: January 5, 1993
    Assignee: University of Houston-University Park
    Inventors: Chase K. McMichael, Wei-Kan Chu
  • Gradient lens fabrication
    Patent number: 4956000
    Abstract: A method for fabricating a lens in which the lens composition is controlled by dynamic shaping and shadowing. A lens material is vaporized and directed to a substrate through an orifice which is rotating relative to the substrate about the lens axis and which has a non-uniform radial distribution. The lens material is condensed on the substrate to form a lens having a radially non-uniform but axially symmetrical distribution. Thereafter, the original orifice may be replaced by a complimentary orifice and another lens material vaporized and directed to the substrate through the replacement orifice which is also rotating relative to the substrate about the lens axis and which also has a non-uniform radial distribution. This second lens material condenses on the first condensed lens material to form a compound lens.
    Type: Grant
    Filed: June 28, 1989
    Date of Patent: September 11, 1990
    Inventors: Robert R. Reeber, Wei-Kan Chu, Salah M. Bedair
  • Method to overcome instability of ultra-shallow semiconductor junctions
    Publication number: 20050260836
    Abstract: A method of forming a stable unction on a microelectronic structure on a semiconductor wafer having a silicon surface layer on a substrate includes the following steps: implanting dopant ions into the surface layer; cleaning and oxidizing the surface layer, and twice annealing the wafer to recover a damaged silicon crystal structure of the surface layer resulting from the low energy ion implantation. The first annealing process uses a temperature range of 800° C. to 1200° C. for a duration from about a fraction of a second to less than about 1000 seconds, with a ramp-up rate of about 50° C./second to about 1000° C./second. The second annealing process uses a temperature range of 400° C. to 650° C. for a time period of from about 1 second to about 10 hours, and more preferably, from about 60 seconds to about 1 hour. Both annealing processes include cooling processes.
    Type: Application
    Filed: July 17, 2003
    Publication date: November 24, 2005
    Inventors: Wei-Kan Chu, Lin Shao, Jiarui Liu
  • Coated substrates and process
    Patent number: 5068020
    Abstract: Disclosed herein is a coated substrate and a process for forming films on substrates and for providing a particularly smooth film on a substrate. The method of this invention involves subjecting a surface of a substrate to contact with a stream of ions of an inert gas having sufficient force and energy to substantially change the surface characteristics of said substrate, and then exposing a film-forming material to a stream of ions of an inert gas having sufficient energy to vaporize the atoms of said film-forming material and to transmit the vaporized atoms to the substrate surface with sufficient force to form a film bonded to the substrate. This process is particularly useful commercially because it forms strong bonds at room temperature.This invention is particularly useful for adhering a gold film to diamond and forming ohmic electrodes on diamond, but also can be used to bond other films to substrates.
    Type: Grant
    Filed: July 10, 1989
    Date of Patent: November 26, 1991
    Assignee: The University of North Carolina at Chapel Hill
    Inventors: Wei-kan Chu, Charles B. Childs
  • EXPLOSIVES DETECTION BY DIRECTIONAL FAST NEUTRON BEAMS SCAN WITH ASSOCIATED PARTICLES
    Publication number: 20070241283
    Abstract: This invention is related to equipment and techniques for fast neutron activation analysis of explosives and /or other warfare agent. The techniques are based on 14 MeV fast neutrons from D-T fusion reaction, the kinematics of the nuclear reaction and fast coincidence between ?-particles of the D-T reaction and ?-quanta from fast neutron induced reactions. A fast neutron generator with effective target cooling and different operation modes provides high neutron yield, long life, and simple maintenance of the equipment and good geometric resolution of the directional neutron beam. High positional resolution of the directionally scanning neutron beam, high time resolution of the coincidence and high neutron yield provide the real time robust screen of explosives with high speed and/or high sensitivity, flexibility for big and small items and overall high probability of detection (PD) and low probability of false alarms (PFA). The remote video scan device also has zooming capability to change solid angle.
    Type: Application
    Filed: April 13, 2006
    Publication date: October 18, 2007
    Applicant: UNIVERSITY OF HOUSTON
    Inventors: Wei-Kan Chu, Jiarui Lui
  • Method to overcome instability of ultra-shallow semiconductor junctions
    Publication number: 20040018703
    Abstract: A method of forming a stable junction on a microelectronic structure on a semiconductor wafer having a silicon surface layer on a substrate includes the following steps: implanting dopant ions into the surface layer; cleaning and oxidizing the surface layer, and twice annealing the wafer to recover a damaged silicon crystal structure of the surface layer resulting from the low energy ion implantation. The first annealing process uses a temperature range of 800° C. to 1200° C. for a duration from about a fraction of a second to less than about 1000 seconds, with a ramp-up rate of about 50° C./second to about 1000° C./second. The second annealing process uses a temperature range of 400° C. to 650° C. for a time period of from about 1 second to about 10 hours, and more preferably, from about 60 seconds to about 1 hour. Both annealing processes include cooling processes.
    Type: Application
    Filed: July 17, 2003
    Publication date: January 29, 2004
    Applicant: University of Houston
    Inventors: Wei-Kan Chu, Lin Shao, Jiarui Liu
  • Method to overcome instability of ultra-shallow semiconductor junctions
    Patent number: 6835626
    Abstract: A method of forming a stable junction on a microelectronic structure on a semiconductor wafer having a silicon surface layer on a substrate includes the following steps: implanting dopant ions into the surface layer; cleaning and oxidizing the surface layer, and twice annealing the wafer to recover a damaged silicon crystal structure of the surface layer resulting from the low energy ion implantation. The first annealing process uses a temperature range of 800° C. to 1200° C. for a duration from about a fraction of a second to less than about 1000 seconds, with a ramp-up rate of about 50° C./second to about 1000° C./second. The second annealing process uses a temperature range of 400° C. to 650° C. for a time period of from about 1 second to about 10 hours, and more preferably, from about 60 seconds to about 1 hour. Both annealing processes include cooling processes.
    Type: Grant
    Filed: July 17, 2003
    Date of Patent: December 28, 2004
    Assignee: University of Houston
    Inventors: Wei-Kan Chu, Lin Shao, Jiarui Liu
  • Explosives detection by directional fast neutron beams scan with associated particles
    Patent number: 7420175
    Abstract: This invention is related to equipment and techniques for fast neutron activation analysis of explosives and /or other warfare agent. The techniques are based on 14 MeV fast neutrons from D-T fusion reaction, the kinematics of the nuclear reaction and fast coincidence between ?-particles of the D-T reaction and ?-quanta from fast neutron induced reactions. A fast neutron generator with effective target cooling and different operation modes provides high neutron yield, long life, and simple maintenance of the equipment and good geometric resolution of the directional neutron beam. High positional resolution of the directionally scanning neutron beam, high time resolution of the coincidence and high neutron yield provide the real time robust screen of explosives with high speed and/or high sensitivity, flexibility for big and small items and overall high probability of detection (PD) and low probability of false alarms (PFA). The remote video scan device also has zooming capability to change solid angle.
    Type: Grant
    Filed: April 13, 2006
    Date of Patent: September 2, 2008
    Assignee: University of Houston
    Inventors: Wei-Kan Chu, Jiarui Lui
  • Thin film structures and method for fabricating same
    Patent number: 4206472
    Abstract: Thin film structures comprising a layer of aluminum and a material having a tendency to interact with aluminum are separated by an intermediate layer of aluminum having a high aluminum oxide content. The intermediate layer prevents said interaction by acting as a diffusion barrier.Preferred embodiments are directed to silicon semiconductor metallization structures, including Schottky barrier contacts, which comprise a bottom layer of tantalum, or other transition metal, or a metal silicide in contact with a silicon substrate, an intermediate layer of aluminum having a high aluminum oxide content and a top layer of aluminum. The intermediate layer functions as a diffusion barrier between aluminum and the metal, metal silicide or silicon.
    Type: Grant
    Filed: December 27, 1977
    Date of Patent: June 3, 1980
    Assignee: International Business Machines Corporation
    Inventors: Wei-Kan Chu, James K. Howard, James F. White
  • Method for fabricating a contact on a semiconductor substrate by depositing an aluminum oxide diffusion barrier layer
    Patent number: 4307132
    Abstract: Thin film structures comprising a layer of aluminum and a material having a tendency to interact with aluminum are separated by an intermediate layer of aluminum having a high aluminum oxide content. The intermediate layer prevents said interaction by acting as a diffusion barrier.Preferred embodiments are directed to silicon semiconductor metallization structures, including Schottky barrier contacts, which comprise a bottom layer of tantalum, or other transition metal, or a metal silicide in contact with a silicon substrate, an intermediate layer of aluminum having a high aluminum oxide content and a top layer of aluminum. The intermediate layer functions as a diffusion barrier between aluminum and the metal, metal silicide or silicon.
    Type: Grant
    Filed: November 7, 1979
    Date of Patent: December 22, 1981
    Assignee: International Business Machines Corp.
    Inventors: Wei-Kan Chu, James K. Howard, James F. White
  • Method of making emitter regions by implantation through a non-monocrystalline layer
    Patent number: 4452645
    Abstract: A transistor structure is provided with an emitter which is formed from non-monocrystalline silicon which is caused to be converted to monocrystalline silicon during the manufacture of the transistor. In the process of manufacturing the present semiconductor structure, a subcollector is formed in a semiconductor substrate. The subcollector dopant out diffuses into a subsequently deposited epitaxial layer. A base region is formed in the epitaxial layer of a conductivity type opposite that of the conductivity type of the subcollector. This results in a PN junction between the base region and the out diffused subcollector impurities forming the collector of the transistor.A layer of non-monocrystalline silicon is deposited on the epitaxial layer. At least a portion of the non-monocrystalline silicon forms a precursor for an emitter region which is contiguous to but vertically displaced from the surface of the base region.
    Type: Grant
    Filed: March 12, 1981
    Date of Patent: June 5, 1984
    Assignee: International Business Machines Corporation
    Inventors: Wei-Kan Chu, Ingrid E. Magdo, Hans S. Rupprecht
  • NMR logging tool with Hi-Tc trap field magnet
    Patent number: 6411087
    Abstract: Trapped field magnets (TFMS) on an NMR logging tool are used to produce a static magnetic field in a formation surrounding a borehole. The TFMs are made of material having a high Tc, so that the magnetic field can be sustained for the duration of the well logging by enclosing the TFMs within a cryostat containing liquid nitrogen as a coolant. By using the TFMs, the field strength within this region is much higher than is attainable with conventional magnets, giving an improved signal to noise (S/N) ratio for the NMR signals. The magnetic field strength within the TFMs is kept at a low enough value that instability problems associated with these materials do not arise. The field strength may be selected based upon knowledge of the resistivity and dielectric constant of the formation and the associated skin depth for electromagnetic signals. This makes it possible to use the TFMs in both wireline and measurement while drilling (MWD) environments.
    Type: Grant
    Filed: May 10, 2000
    Date of Patent: June 25, 2002
    Assignee: University of Houston
    Inventors: Nongqiang Fan, Wei-Kan Chu
  • FORMATION METHOD OF SEMICONDUCTOR DEVICE STRUCTURE WITH METAL-SEMICONDUCTOR COMPOUND REGION
    Publication number: 20200020583
    Abstract: A method for forming a semiconductor device structure is provided. The method includes forming a fin structure over a semiconductor substrate and forming a gate stack over the fin structure. The method also includes forming an epitaxial structure over the fin structure, and the epitaxial structure is adjacent to the gate stack. The method further includes forming a dielectric layer over the epitaxial structure and forming an opening in the dielectric layer to expose the epitaxial structure. In addition, the method includes applying a metal-containing material on the epitaxial structure while the epitaxial structure is heated so that a portion of the epitaxial structure is transformed to form a metal-semiconductor compound region.
    Type: Application
    Filed: July 13, 2018
    Publication date: January 16, 2020
    Applicant: Taiwan Semiconductor Manufacturing Co., Ltd.
    Inventors: Yi-Hsiang CHAO, Min-Hsiu HUNG, Chun-Wen NIEH, Ya-Huei LI, Yu-Hsiang LIAO, Li-Wei CHU, Kan-Ju LIN, Kuan-Yu YEH, Chi-Hung CHUANG, Chih-Wei CHANG, Ching-Hwanq SU, Hung-Yi HUANG, Ming-Hsing TSAI
  • Method for fabricating nanoparticles containing fenofibrate
    Publication number: 20080161594
    Abstract: A method employs the addition of additive to increase the solubility of active ingredients in solution. Furthermore, a nanoparticle apparatus that uses inkjet dispenser is utilized to fabricate nanoparticles. The method comprises: (a) mixing a fenofibrate substance, an organic solvent and a solubility enhancing additive to form a saturated solution; and (b) spray-drying the saturated solution to form the nanoparticles containing fenofibrate, wherein the solubility enhancing additive comprises a surfactant or an excipient.
    Type: Application
    Filed: December 29, 2006
    Publication date: July 3, 2008
    Applicant: INDUSTRIAL TECHNOLOGY RESEARCH INSTITUTE
    Inventors: John Jianghann Lin, Chu Chun Hsueh, Pei Kan, Po-Fu Chou, En-Wei Chang, Wei-Liang Hsu
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