Patents by Inventor James B. Boyce

James B. Boyce 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: 6107641
    Abstract: An improved thin film transistor structure is provided having no source/gate or drain/gate overlap. A laser doping technique is applied to fabricate such transistors. Eliminating source/gate and drain/gate overlap significantly reduces or eliminates parasitic capacitance and feed-through voltage between source and gate. Short-channel a-Si:H thin film transistors may be obtained having high field effect mobilities. Improved pixel performance and pixel-to-pixel uniformity is provided.
    Type: Grant
    Filed: September 10, 1997
    Date of Patent: August 22, 2000
    Assignee: Xerox Corporation
    Inventors: Ping Mei, Rene A. Lujan, James B. Boyce, Christopher L. Chua, Michael G. Hack
  • Patent number: 6051827
    Abstract: A pixel circuit construction for image sensing includes a photosensor, an amplifier, a selector switch and, and a reset switch. The amplifier may be a single polycrystalline silicon (channel) transistor for high gain. The selector switch may also be a single polycrystalline silicon (channel) transistor for high conductivity. The reset switch may a single amorphous crystalline silicon (channel) transistor for low leakage current. The photosensor and amplifier may be connected to a shared bias line or may be connected to separate bias and drive lines, respectively. The selector and reset switches may be connected to a shared data line or may be connected to separate data and reset lines, respectively. Laser crystallization and rehydrogenation techniques are well suited to obtaining devices described herein. Threshold response is provided.
    Type: Grant
    Filed: April 28, 1998
    Date of Patent: April 18, 2000
    Assignee: Xerox Corporation
    Inventors: Ping Mei, Andrew J. Moore, Raj B. Apte, Steven E. Ready, Robert A. Street, James B. Boyce
  • Patent number: 6031248
    Abstract: A pixel circuit construction for image sensing includes a photosensor, an amplifier, a selector switch and, and a reset switch. The amplifier may be a single polycrystalline silicon (channel) transistor for high gain. The selector switch may also be a single polycrystalline silicon (channel) transistor for high conductivity. The reset switch may a single amorphous crystalline silicon (channel) transistor for low leakage current. The photosensor and amplifier may be connected to a shared bias line or may be connected to separate bias and drive lines, respectively. The selector and reset switches may be connected to a shared data line or may be connected to separate data and reset lines, respectively. Laser crystallization and rehydrogenation techniques are well suited to obtaining devices described herein.
    Type: Grant
    Filed: April 28, 1998
    Date of Patent: February 29, 2000
    Assignee: Xerox Corporation
    Inventors: Ping Mei, Andrew J. Moore, Raj B. Apte, Steven E. Ready, Robert A. Street, James B. Boyce
  • Patent number: 6019796
    Abstract: A method of producing an improved thin film transistor structure is provided having no source/gate or drain/gate overlap. A laser-assisted doping technique is applied to fabricate such transistors. A radiation filter is employed, which is transparent to light at the photolithography wavelength, but reflective or opaque at the laser wavelength. Eliminating source/gate and drain/gate overlap significantly reduces or eliminates parasitic capacitance and feed-through voltage between source and gate. Short-channel a-Si:H thin film transistors may be obtained having high field effect mobilities. Improved pixel performance and pixel-to-pixel uniformity is provided.
    Type: Grant
    Filed: October 29, 1997
    Date of Patent: February 1, 2000
    Assignee: Xerox Corporation
    Inventors: Ping Mei, Rene A. Lujan, James B. Boyce, Christopher L. Chua, Michael G. Hack
  • Patent number: 6020223
    Abstract: A method of producing an improved thin film transistor structure is provided having no source/gate or drain/gate overlap. A laser-assisted doping technique is applied to fabricate such transistors. A radiation filter is employed, which is transparent to light at the photolithography wavelength, but reflective or opaque at the laser wavelength. Eliminating source/gate and drain/gate overlap significantly reduces or eliminates parasitic capacitance and feed-through voltage between source and gate. Short-channel a-Si:H thin film transistors may be obtained having high field effect mobilities. Improved pixel performance and pixel-to-pixel uniformity is provided.
    Type: Grant
    Filed: October 29, 1997
    Date of Patent: February 1, 2000
    Assignee: Xerox Corporation
    Inventors: Ping Mei, Rene A. Lujan, James B. Boyce, Christopher L. Chua, Michael G. Hack
  • Patent number: 6011531
    Abstract: This invention relates to methods and applications of forming clusters of pixels in 2-D sensing and display arrays. Using TFT switches having more than one predetermined electrical characteristics. The array formed according to these teachings being used in sensing, displaying, adjusting resolution, color selection, image processing, object recognition and filtering.
    Type: Grant
    Filed: October 21, 1996
    Date of Patent: January 4, 2000
    Assignee: Xerox Corporation
    Inventors: Ping Mei, James B. Boyce, Robert A. Street, David K. Fork
  • Patent number: 6005238
    Abstract: A pixel circuit construction for image sensing includes a photosensor, an amplifier, a selector switch and, and a reset switch. The amplifier may be a single polycrystalline silicon (channel) transistor for high gain. The selector switch may also be a single polycrystalline silicon (channel) transistor for high conductivity. The reset switch may a single amorphous crystalline silicon (channel) transistor for low leakage current. The photosensor and amplifier may be connected to a shared bias line or may be connected to separate bias and drive lines, respectively. The selector and reset switches may be connected to a shared data line or may be connected to separate data and reset lines, respectively. Laser crystallization and rehydrogenation techniques are well suited to obtaining devices described herein. Linearization of output response is provided.
    Type: Grant
    Filed: April 28, 1998
    Date of Patent: December 21, 1999
    Assignee: Xerox Corporation
    Inventors: Ping Mei, Andrew J. Moore, Raj B. Apte, Steven E. Ready, Robert A. Street, James B. Boyce
  • Patent number: 5893948
    Abstract: The invention provides a method for forming a plurality of single silicon crystals over a substrate. The method forms a plurality of nucleation sites over the substrate. An amorphous silicon layer is formed over the substrate covering the plurality of silicon nucleation sites. The amorphous silicon layer is melted by using a laser beam and then crystallized to form the plurality of single silicon crystals. Each of the plurality of single silicon crystals correspond to one of the plurality of nucleation sites.
    Type: Grant
    Filed: April 5, 1996
    Date of Patent: April 13, 1999
    Assignee: Xerox Corporation
    Inventors: Norbert H. Nickel, Gregory B. Anderson, Steven E. Ready, James B. Boyce, Ping Mei
  • Patent number: 5871826
    Abstract: This invention relates to a method of altering the electrical characteristics of a material through a laser ablation process. It can achieve high doping levels and shallow junctions at low temperatures, which are desirable in the fabrication of thin film transistors.
    Type: Grant
    Filed: May 30, 1996
    Date of Patent: February 16, 1999
    Assignee: Xerox Corporation
    Inventors: Ping Mei, Rene A. Lujan, James B. Boyce
  • Patent number: 5821135
    Abstract: A transparent substrate as formed on its front side a layer of amorphous silicon. A laser beam is used to irradiate through the backside of the transparent substrate in order to form buried nucleation sites within the amorphous silicon. The buried nucleation sites which are used as nucleation seeds are then used during a front side crystallization process in order to form large single silicon crystals over the substrate surface.
    Type: Grant
    Filed: October 16, 1996
    Date of Patent: October 13, 1998
    Assignee: Xerox Corporation
    Inventors: Ping Mei, Gregory B. Anderson, James B. Boyce, David K. Fork, Richard I. Johnson
  • Patent number: 5733641
    Abstract: The invention provides a buffered substrate that includes a substrate, a buffer layer and a silicon layer. The buffer layer is disposed between the substrate and the silicon layer. The buffer layer has a melting point higher than a melting point of the substrate. A polycrystalline silicon layer is formed by crystallizing the silicon layer using a laser beam.
    Type: Grant
    Filed: May 31, 1996
    Date of Patent: March 31, 1998
    Assignee: Xerox Corporation
    Inventors: David K. Fork, James B. Boyce, Ping Mei, Steve Ready, Richard I. Johnson, Greg B. Anderson
  • Patent number: 5366926
    Abstract: A low temperature process for dehydrogenating amorphous silicon using lasers. Dehydrogenation occurs by irradiating one or more areas of a hydrogenated amorphous silicon layer with laser beam pulses at a relatively low energy density. After the multiple laser pulse irradiation at a relatively low energy density, the laser energy density is increased and multiple irradiation at a higher energy density is performed. If after the multiple irradiation at the higher energy density the amorphous silicon hydrogen content is still too high, dehydrogenation proceeds by multiple irradiations at a yet higher energy density. The irradiation at the various energy densities can result in the formation of polysilicon due to melting of the amorphous silicon layer. As irradiation may be selectively applied to the amorphous silicon, an integral amorphous silicon-polysilicon structure may be formed.
    Type: Grant
    Filed: June 7, 1993
    Date of Patent: November 22, 1994
    Assignee: Xerox Corporation
    Inventors: Ping Mei, James B. Boyce, Richard I. Johnson, Michael G. Hack, Rene A. Lujan
  • Patent number: 5358925
    Abstract: An HTSC material epitaxially deposited on a YSZ buffer layer on a surface of a monocrystalline silicon substrate has a zero resistance transition temperature of at least 85.degree. K., a transition width (10-90%) of no more than 1.0.degree. K., a resistivity at 300.degree. K. of no more than 300 micro-ohms-centimeter and a resistivity ratio (at 300.degree. K./100.degree. K.) of 3.0.+-. 0.2. The surface of the silicon substrate is cleaned using a spin-etch process to produce an atomically clean surface terminated with an atomic layer of an element such as hydrogen with does not react with silicon. The substrate can be moved to a deposition chamber without contamination. The hydrogen is evaporated in the chamber, and then YSZ is epitaxially deposited preferably by laser ablation. Thereafter, the HTSC material, such as YBCO, is epitaxially deposited preferably by laser ablation. The structure is then cooled in an atmosphere of oxygen.
    Type: Grant
    Filed: August 10, 1992
    Date of Patent: October 25, 1994
    Assignee: Board of Trustees of the Leland Stanford Junior University
    Inventors: George A. Neville Connell, David B. Fenner, James B. Boyce, David K. Fork
  • Patent number: 5173474
    Abstract: An HTSC material epitaxially deposited on a YSZ buffer layer on a surface of a monocrystalline silicon substrate has a zero resistance transition temperature of at least 85.degree. K., a transition width (10-90%) of no more than 1.0.degree. K., a resistivity at 300.degree. K. of no more than 300 micro-ohms-centimeter and a resistivity ratio (at 300.degree. K./100.degree. K.) of 3.0.+-.0.2. The surface of the silicon substrate is cleaned using a spin-etch process to produce an atomically clean surface terminated with an atomic layer of an element such as hydrogen with does not react with silicon. The substrate can be moved to a deposition chamber without contamination. The hydrogen is evaporated in the chamber, and then YSZ is epitaxially deposited preferably by laser ablation. Thereafter, the HTSC material, such as YBCO, is epitaxially deposited preferably by laser ablation. The structure is then cooled in an atmosphere of oxygen.
    Type: Grant
    Filed: March 11, 1991
    Date of Patent: December 22, 1992
    Assignees: Xerox Corporation, President and Board of Trustees of Santa Clara College, Board of Trustees of the Leland Stanford Junior University
    Inventors: George A. N. Connell, David B. Fenner, James B. Boyce, David K. Fork