Patents by Inventor Hirofumi Uenoyama

Hirofumi Uenoyama 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: 5936159
    Abstract: A semiconductor sensor including a movable member beam structure having a reduced deflection characteristic. The sensor includes a movable beam structure film suspended from a semiconductor substrate, with a gap interposed between the beam structure film and the substrate. The beam structure film is composed of a plurality of film layers that are laminated in a direction of film thickness. Further, a stress relieving layer is interposed between respective films to reduce overall internal stress on the structure.
    Type: Grant
    Filed: November 25, 1996
    Date of Patent: August 10, 1999
    Assignee: Nippondenso Co., Ltd.
    Inventors: Kazuhiko Kano, Yukihiro Takeuchi, Takamoto Watanabe, Kenichi Ao, Masakazu Kanosue, Hirofumi Uenoyama
  • Patent number: 5851851
    Abstract: It is an object to provide a method of fabrication for a semiconductor acceleration sensor which can prevent destruction of a movable portion during dicing. A sacrificial layer composed of silicon oxide film is formed on a silicon substrate, and a movable member composed of polycrystalline silicon is formed on the sacrificial layer. A polyimide film is applied on the movable member at room temperature and heated to approximately 350.degree. C. to harden. The movable member is supported by this polyimide film. Accordingly, etching liquid penetration holes are formed on the polyimide film. Further, the sacrificial layer disposed between the movable member and the silicon substrate is etched away by means of dipping the silicon substrate into hydrofluoric acid-based etching liquid. Thereafter, the silicon substrate is dipped into demineralized water to replace the etching liquid with demineralized water, and subsequently the silicon substrate is dried.
    Type: Grant
    Filed: March 6, 1995
    Date of Patent: December 22, 1998
    Assignee: Nippondenso Co., Ltd.
    Inventors: Hirofumi Uenoyama, Masakazu Kanosue, Kenichi Ao, Yasutoshi Suzuki
  • Patent number: 5627397
    Abstract: A semiconductor acceleration sensor according to the present invention performs acceleration detection by means of detecting increase or decrease in electrical current flowing between fixed electrodes formed on a semiconductor substrate taking a movable section in a movable state supported on the semiconductor substrate as a gate electrode. Two transistor structures are utilized in this detection. Current between fixed electrodes in one transistor structure increases when the movable section is subjected to acceleration and is displaced. At that time, current between fixed electrodes in the other transistor structure decreases. These two transistor structures are disposed proximately. By means of this proximate disposition, fluctuations in characteristics of both transistors are reduced, and by means of acceleration detection by differential type, temperature characteristics of the two transistors can be canceled favorably.
    Type: Grant
    Filed: March 13, 1995
    Date of Patent: May 6, 1997
    Assignee: Nippondenso Co., Ltd.
    Inventors: Kazuhiko Kano, Yukihiro Takeuchi, Takamoto Watanabe, Kenichi Ao, Masakazu Kanosue, Hirofumi Uenoyama, Kenichi Nara
  • Patent number: 5618738
    Abstract: A method of manufacturing a magnetoresistance element that can accurately sort out truely defective products from apparently defective products due to the manufacturing processes. Manufacturing processes for MR elements includes a MR element formation process, a magnetic field application process and an electric inspection process. In the magnetic field process, the magnetic field application is limited to a range within 75.degree. to the longitudinal direction of a MR element pattern. By performing the magnetic field application process before the electric inspection process, the anisotropic magnetic field due to a shape magnetic anisotropy of the MR element can be aligned almost in a fixed direction, defective products due to the manufacturing processes can exactly be sorted out from the apparently defective products in the electric inspection process, so that the yield rate can be improved.
    Type: Grant
    Filed: March 14, 1995
    Date of Patent: April 8, 1997
    Assignee: Nippondenso Co., Ltd.
    Inventors: Kenichi Ao, Minoru Murata, Hiroki Noguchi, Yoshimi Yoshino, Hirofumi Uenoyama
  • Patent number: 5619050
    Abstract: A semiconductor acceleration sensor capable of reducing a leakage current and manufacturing method thereof is disclosed. A beam structure is disposed on a silicon substrate. The beam structure has a movable section, and the movable section is disposed spaced at a prescribed distance above silicon substrate. A movable electrode section is formed in one portion of movable section. Fixed electrodes made of an impurity diffusion layer are formed in silicon substrate to correspond to both sides of a movable electrode section. A peripheral circuit is formed in silicon substrate. The beam structure and the peripheral circuit are electrically connected by an electroconductive thin film, made of polysilicon. Then, when a voltage is applied to the beam structure, and a voltage is applied to both fixed electrodes, an inversion layer is formed, and an electrical current flows between the fixed electrodes.
    Type: Grant
    Filed: March 6, 1995
    Date of Patent: April 8, 1997
    Assignee: Nippondenso Co., Ltd.
    Inventors: Hirofumi Uenoyama, Kenichi Ao, Masakazu Kanosue, Yasutoshi Suzuki, Yukihiro Takeuchi
  • Patent number: 5587343
    Abstract: A method for fabricating a semiconductor sensor wherein deflection of a movable member is disclosed. A silicon oxide film is formed on a silicon substrate, and a movable member composed of polycrystalline silicon is formed on the silicon oxide film by means of a low-pressured chemical vapor deposition process. At this time, silane is caused to flow into an oven, and the supply of silane is stopped when a layer of polycrystalline silicon has been deposited on the silicon substrate, and a first polycrystalline silicon layer is formed. By means of stopping the supply of silane, a silicon oxide layer of a thickness of several angstroms to several tens of angstroms is formed on the first polycrystalline silicon layer by atmosphere O.sub.2. A second polycrystalline silicon layer of a thickness of 1 .mu.m is formed on the silicon oxide layer by means of causing silane to flow into the oven. Patterning by dry etching or the like through a photo-lithographic process is performed to form a movable member.
    Type: Grant
    Filed: March 8, 1995
    Date of Patent: December 24, 1996
    Assignee: Nippondenso Co., Ltd.
    Inventors: Kazuhiko Kano, Yukihiro Takeuchi, Takamoto Watanabe, Kenichi Ao, Masakazu Kanosue, Hirofumi Uenoyama
  • Patent number: 5551586
    Abstract: A method of manufacturing a magneto-electric conversion device having a large rate of change of magnetic resistance and which is easy to position with respect to a magnetized surface, and a moving subject displacement detector using a magneto-electric conversion device manufactured by that method. A magnet which rotates together with the rotation of a drive gear is magnetized in alternately differing north and south poles, arranged in an equal sized section from a center portion thereof. An IC chip is positioned opposite to and at a distance from the magnetized surface of the magnet. Magneto-electric conversion devices are located on the IC chip. These magneto-electric conversion devices are formed by repeated alternate depositions, onto a surface of a single-crystal silicon substrate, of magnetic cobalt films having a thickness of several to several tens of angstroms and non-magnetic copper films having a thickness of several to several tens of angstroms.
    Type: Grant
    Filed: August 24, 1994
    Date of Patent: September 3, 1996
    Assignee: Nippondenso Co., Ltd.
    Inventors: Hirofumi Uenoyama, Kenichi Ao, Yasutoshi Suzuki, Yoshimi Yoshino, Motofumi Suzuki
  • Patent number: 5471084
    Abstract: This invention relates to a magnetoresistive element used for a magnetic sensor, etc. A ferromagnetic magnetoresistive element thin film is formed so as to be electrically connected to and so as to overlap the upper end portion of an aluminum wiring metal on a substrate. Through using a vacuum heat treatment with a temperature between 350.degree. and 450.degree. C., a Ni--Al-based alloy is formed at the overlapping portion. Therefore, even when a surface protection film of silicon nitride is subsequently formed by plasma CVD on the substrate, the alloy prevents the nitriding of the upper end portion of the aluminum wiring metal. Accordingly, the surface can be protected from moisture by the silicon nitride film without increasing the contact resistance between the magnetoresistive element thin film and the wiring metal. Instead of the Ni--Al-based alloy, other conductive metals such as TiW, TiN, Ti, Zr, or the like may be used.
    Type: Grant
    Filed: July 30, 1993
    Date of Patent: November 28, 1995
    Assignee: Nippondenso Co., Ltd.
    Inventors: Yasutoshi Suzuki, Kenichi Ao, Hirofumi Uenoyama, Hiroki Noguchi, Koji Eguchi, Ichiro Ito, Yoshimi Yoshino