Physical Stress Responsive Patents (Class 438/50)
  • Patent number: 5668033
    Abstract: On a silicon wafer there is formed a movable gate MOS transistor (sensing element: functional element). A bonding frame consisting of a silicon thin film is patterned around an element formation region on the surface of the silicon wafer. On a cap forming silicon wafer there is projectively provided a leg portion on the bottom surface of which a bonding layer consisting of a gold film is formed. The cap forming silicon wafer is disposed on the silicon wafer, whereupon heating with respect thereto is performed at a temperature equal to higher than a gold/silicon eutectic temperature to thereby make bondage between the bonding frame of the silicon wafer and the bonding layer of the cap forming silicon wafer. Thereafter, the both wafers are diced in chip units.
    Type: Grant
    Filed: May 17, 1996
    Date of Patent: September 16, 1997
    Assignee: Nippondenso Co., Ltd.
    Inventors: Fumio Ohara, Shinji Yoshihara, Katuhiko Kanamori, Takashi Kurahashi
  • Patent number: 5660680
    Abstract: This invention relates to the area of microelectromechanical systems in which electronic circuits and mechanical devices are integrated on the same silicon chip. The method taught herein allows the fabrication of thin film structures in excess of 150 microns in height using thin film deposition processes. Wafers may be employed as reusable molds for efficient production of such structures.
    Type: Grant
    Filed: March 7, 1994
    Date of Patent: August 26, 1997
    Assignee: The Regents of the University of California
    Inventor: Christopher G. Keller
  • Patent number: 5656846
    Abstract: An acceleration sensor is provided with damping means on an upper surface and/or an lower surface of a movable portion of a sensor body and/or opposite regions surrounded by the movable portion and a rim of the sensor body in order to provide damping of a vibration to the movable portion of the sensor body. The damping means includes a material having a large mechanical damping constant, for example, a plastic, a gel, an inorganic material, and micro capsules. In a fabrication process of the acceleration sensor, a supporting film is provided on the movable portion of the sensor body, the damping material is provided on the supporting film and the movable portion of the sensor body is subjected to etching so as to form a weight and a diaphragm.
    Type: Grant
    Filed: March 7, 1995
    Date of Patent: August 12, 1997
    Assignee: NEC Corporation
    Inventor: Keizo Yamada
  • Patent number: 5628917
    Abstract: A masking process resulting from a modified version of the SCREAM process is used for the fabrication of ultra-high aspect ratio, wafer-free, single crystal silicon movable micromechanical devices and frame structures of large vertical depth and narrow linewidth. The process is single-mask, self-aligned and allows the formation of releasable three-dimensional frame-like objects of arbitrary shape which can be made up to about half the wafer thickness in depth and can be subsequently lifted off the substrate and placed on any other material to be used as a mask or to be integrated with other devices. The process consists of a single lithography step and a repeated sequence of thermal oxidations and reactive ion etchings.
    Type: Grant
    Filed: February 3, 1995
    Date of Patent: May 13, 1997
    Assignee: Cornell Research Foundation, Inc.
    Inventors: Noel C. MacDonald, Ali Jazairy
  • Patent number: 5629243
    Abstract: A method is described for manufacturing a miniaturized accelerometer having a narrow bandwidth and behaving as a switch sensitive only to low frequencies such as are contained in earthquakes. The method includes provision of an unbalanced see-saw beam assembly composed of beams 2 and masses 3 at opposite ends of the beams 2. The beams 2 have their suspension at a location with slightly different distances from the masses 3 along a line parallel to and vertically offset from the line connecting centers of gravity of the masses 3.
    Type: Grant
    Filed: September 14, 1995
    Date of Patent: May 13, 1997
    Assignee: Tokyo Gas Co., Ltd.
    Inventors: Sean S. Cahill, Walter Shoeys, Kenichi Nakamura
  • Patent number: 5622902
    Abstract: A method for passivating diamond films to substantially prevent them from oxidizing at temperatures up to 800.degree. C. in an oxygen atmosphere. The method involves depositing one or more passivating layers over the diamond film wherein one of the layers is nitride and the other layer is quartz. The passivation technique is directly applicable to diamond sensor pressure transducers and enable them to operate at temperatures above 800.degree. C. in oxygen environments. The passivation technique also provides an economical and simple method for patterning diamond films.
    Type: Grant
    Filed: March 14, 1996
    Date of Patent: April 22, 1997
    Assignee: Kulite Semiconductor Products, Inc.
    Inventors: Anthony D. Kurtz, Alexander A. Ned, Timoteo I. Vergel de Dios
  • Patent number: 5622901
    Abstract: In a semiconductor strain sensor, for example, using resistors of a polycrystalline semiconductor material such as polycrystalline silicon as strain gauges, the sum of the temperature coefficient of resistance (TCR) of the resistor and the temperature coefficient of strain sensitivity (TCK) is adjusted not by controlling the impurity carrier concentration but by controlling the resistivity, thereby an output fluctuation due to a change in the temperature can be suppressed.
    Type: Grant
    Filed: August 2, 1994
    Date of Patent: April 22, 1997
    Assignee: Nippondenso Co., Ltd.
    Inventor: Tsuyoshi Fukada
  • Patent number: 5620929
    Abstract: A gas flow type sensor with heat-wire bridge having an excellent performance which is attained by optimizing a sputtering process and a heat treatment process for forming a three-layer film (SiN-Pt-SiN) on a semiconductor substrate and improving interfacial adhesion of the three layers and, at the same time, effectively reducing any interfacial stress produced therein. The process comprises a film forming process for sequentially depositing by sputtering SiN, Pt and SiN in three layers on a semiconductor substrate and a heat treatment process for heat treatment of the coated films at a temperature up to 600.degree. C.
    Type: Grant
    Filed: April 3, 1995
    Date of Patent: April 15, 1997
    Assignee: Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Takashi Hosoi, Mizuho Doi, Nariaki Kuriyama
  • Patent number: 5620931
    Abstract: A monolithic capacitance-type microstructure includes a semiconductor substrate, a plurality of posts extending from the surface of the substrate, a bridge suspended from the posts, and an electrically-conductive, substantially stationary element anchored to the substrate. The bridge includes an element that is laterally movable with respect to the surface of the substrate. The substantially stationary element is positioned relative to the laterally movable element such that the laterally movable element and the substantially stationary element form a capacitor. Circuitry may be disposed on the substrate and operationally coupled to the movable element and the substantially stationary element for processing a signal based on a relative positioning of the movable element and the substantially stationary element. A method for fabricating the microstructure and the circuitry is disclosed.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: April 15, 1997
    Assignee: Analog Devices, Inc.
    Inventors: Robert W. K. Tsang, Theresa A. Core
  • Patent number: 5616514
    Abstract: A micromechanical sensor includes a support of silicon substrate having an epitaxial layer of silicon applied on the silicon substrate. A part of the epitaxial layer is laid bare to form at least one micromechanical deflection part by an etching process. The bared deflection part is made of polycrystalline silicon which has grown in polycrystalline form during the epitaxial process over a silicon-oxide layer which has been removed by etching. In the support region and/or at the connection to the silicon substrate, the exposed deflection part passes into single crystal silicon. By large layer thicknesses, a large working capacity of the sensor is possible. The sensor structure provides enhanced mechanical stability, processability, and possibilities of shaping, and it can be integrated, in particular, in a bipolar process or mixed process (bipolar-CMOS, bipolar-CMOS-DMOS).
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: April 1, 1997
    Assignee: Robert Bosch GmbH
    Inventors: Joerg Muchow, Horst Muenzel, Michael Offenberg, Winfried Waldvogel
  • Patent number: 5616523
    Abstract: A method for manufacturing sensors from a multilayer plate with upper and lower monocrystalline silicon layers and an etching layer between them. The upper silicon layer is structured by the introduction of troughs therein extending down to the etching layer. Sensor structures, such as a bending beam that is used in an acceleration sensor, are created by etching the etching layer beneath a part of the silicon layer structured in this manner.
    Type: Grant
    Filed: April 2, 1996
    Date of Patent: April 1, 1997
    Assignee: Robert Bosch GmbH
    Inventors: Gerhard Benz, Jiri Marek, Frank Bantien, Horst Muenzel, Franz Laermer, Michael Offenberg, Andrea Schilp