Patents Examined by James Carroll
  • Patent number: 4777516
    Abstract: The invention relates to the fabrication of modules consisting of a number of light-emitting elements (10) and the associated driver electronics (11) integrated on a common conductive p-type Gallium Arsenide substrate (12). The use of a number of such modules to form in a recording head an uninterrupted row of light-emitting elements is furthermore disclosed.
    Type: Grant
    Filed: April 10, 1986
    Date of Patent: October 11, 1988
    Assignee: Agfa-Gevaert, N.V.
    Inventors: Marc M. Deschler, Meino Heyen
  • Patent number: 4758869
    Abstract: A field effect transistor includes a source region, a drain region, and a channel region formed in a semiconductor substrate and a floating gate and a control gate formed over the substrate. An opaque cover (typically aluminum) is formed over but electrically insulated from the transistor to prevent light from striking and affecting the electrical charge on the floating gate. The periphery of the opaque cover ohmically contacts the semiconductor substrate, thereby limiting the amount of light reaching the floating gate, except where the source and drain extend inwardly beyond the periphery of the opaque cover. The control gate extends over a portion of the substrate surrounding the transistor, and helps hinder light from reaching the floating gate. In addition, semiconductor material formed concurrently with the control gate extends over the source and drain regions, thereby providing additional shading.
    Type: Grant
    Filed: August 29, 1986
    Date of Patent: July 19, 1988
    Assignee: WaferScale Integration, Inc.
    Inventors: Boaz Eitan, Reza Kazerounian
  • Patent number: 4745448
    Abstract: A field effect transistor includes a substrate of gallium arsenide having a resistivity of at least about 10.sup.7 ohm/cm and a first buffer layer of gallium arsenide disposed over the substrate having a deep level acceptor dopant incorporated into the buffer layer to compensate for donor dopants incorporated into the buffer layer. The concentration of the donor dopants and the acceptor dopant are controlled to provide the buffer layer with a predetermined resistivity characteristic of about 10.sup.7 -10.sup.8 ohm/cm. The concentration of the deep acceptor dopant is substantially constant at about 10.sup.16 acceptors/cc throughout the first buffer layer. The buffer layer preferably has a thickness of at least 2 microns and preferably between 5 and 30 microns. A second buffer layer is disposed over the first buffer layer having a monotonically declining concentration of chromium dopant from about 10.sup.16 to less than about 10.sup.14 acceptors/cc.
    Type: Grant
    Filed: December 24, 1985
    Date of Patent: May 17, 1988
    Assignee: Raytheon Company
    Inventors: H. Barteld Van Rees, Barry J. Liles
  • Patent number: 4733283
    Abstract: A method of manufacturing a GaAS semiconductor device of an E/D construction having a GaAs/AlGaAs heterojunction and utilizing a two-dimensional electron gas, which includes the steps of forming a heterojunction semiconductor substrate and etching a portion of the substrate to provide a gate portion of a depletion-mode FET. When the substrate of a semi-insulating GaAs layer, an undoped GaAs, an N-type AlGaAs layer providing an electron-supply layer, and a GaAs layer is formed, the GaAs layer is composed of a first GaAs layer, an etching stoppable AlGaAs layer, and a second GaAs layer, the first GaAs layer being formed on the N-type GaAs layer. The etching for provision of the gate portion is carried out by a dry etching method using an etchant of CCl.sub.2 F.sub.2 gas, so that the second GaAs layer can be etched but the AlGaAs layer cannot be etched.
    Type: Grant
    Filed: September 19, 1986
    Date of Patent: March 22, 1988
    Assignee: Fujitsu Limited
    Inventor: Shigeru Kuroda
  • Patent number: 4729006
    Abstract: A method for forming fully recessed (planar) isolation regions on a semiconductor for the manufacture of CMOS integrated circuits, and the resulting semiconductor structure, comprising in a P doped silicon substrate with mesas formed therein, forming low viscosity sidewall spacers of borosilicate glass in contact with the sidewalls of those mesas designated to have N-channel devices formed therein; then filling the trenches in the substrate adjacent to the mesas with TEOS; and heating the structure until the boron in the sidewall spacers diffuses into the sidewalls of the designated mesas to form channel stops. These sidewall spacers reduce the occurrence of cracks in the TEOS by relieving internal mechanical stress therein and permit the formation of channel stops via diffusion, thereby permitting mesa walls to be substantially vertical.
    Type: Grant
    Filed: March 17, 1986
    Date of Patent: March 1, 1988
    Assignee: International Business Machines Corporation
    Inventors: Anthony J. Dally, Seiki Ogura, Jacob Riseman, Nivo Rovedo