Patents by Inventor Yuichi Yokoyama

Yuichi Yokoyama 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: 5831323
    Abstract: There are provided a semiconductor device, which includes an element isolating oxide film having a good upper flatness, and a method of manufacturing the same. Assuming that t.sub.G represents a thickness of a gate electrode layer 6, a height t.sub.U to an upper surface of a thickest portion of element isolating oxide film 4 from an upper surface of a gate insulating film 5 and an acute angle .theta.i defined between the upper surfaces of element isolating oxide film 4 and gate insulating film are set within ranges expressed by the formula of {.theta.i, t.sub.U .linevert split.0.ltoreq..theta.i.ltoreq.56.6.degree., 0.ltoreq.t.sub.U .ltoreq.0.82t.sub.G }. Thereby, an unetched portion does not remain at an etching step for patterning the gate electrode layer to be formed later. This prevents short-circuit of the gate electrode. Since the element isolating oxide film has the improved flatness, a quantity of overetching in an active region can be reduced at a step of patterning the gate electrode.
    Type: Grant
    Filed: February 14, 1996
    Date of Patent: November 3, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kaoru Motonami, Shigeru Shiratake, Hiroshi Matsuo, Yuichi Yokoyama, Kenji Morisawa, Ritsuko Gotoda, Takaaki Murakami, Satoshi Hamamoto, Kenji Yasumura, Yasuyoshi Itoh
  • Patent number: 5780870
    Abstract: A semiconductor device is provided for convenient checking of etching states of semiconductor layers, along with a process for its preparation, wherein a test layer is formed on the same wafer where a semiconductor product is manufactured, and concurrently with and under the same formation conditions as formation a target layer forming a part of the semiconductor product, wherein the test layer is formed on a first layer and on a second layer interposed between a portion of the test layer and the first layer, with one of the first and second layers having the same etching properties as the target layer and the other of the first and second layers having different etching characteristics from the target layer.
    Type: Grant
    Filed: September 30, 1996
    Date of Patent: July 14, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hitoshi Maeda, Yukinori Hirose, Yuichi Yokoyama
  • Patent number: 5747843
    Abstract: An improved semiconductor memory device in which an electric circuit operates normally is provided. A block of memory cells of a dynamic random access memory is provided on a semiconductor substrate. A dummy storage node is provided near a corner portion of the memory cell block. A dummy cell plate is provided such that it covers the dummy storage node and is electrically insulated from a main cell plate of the DRAM.
    Type: Grant
    Filed: June 21, 1996
    Date of Patent: May 5, 1998
    Assignees: Mitsubishi Denki Kabushiki Kaisha, Ryoden Semiconductor System Engineering Corporation
    Inventors: Hiroshi Matsuo, Shinya Watanabe, Yuichi Yokoyama, Shinya Inoue
  • Patent number: 5747694
    Abstract: A pressure sensor has a resin housing containing a pressure sensor positioned between a reference pressure chamber and a pressure to be measured. A terminal extends through the housing toward the sensor. A wire connects the terminal to the sensor. When a connector is connected to the terminal, it may compress air around the terminal. The compressed air may travel along the terminal and break the wire connected to the sensor. To prevent such breakage, a barrier wall is provided to block the compressed air from penetrating toward the wire. The reference pressure chamber is divided into a main chamber and a subchamber by the barrier wall. Since the barrier wall blocks the compressed air, the compressed air can not reach a silicon gel on the sensor and the wire in the main chamber. Therefore, the wire is protected.
    Type: Grant
    Filed: July 26, 1996
    Date of Patent: May 5, 1998
    Assignee: Nippondenso Co., Ltd.
    Inventors: Horonobu Baba, Tiaki Mizuno, Masahito Imai, Yuichi Yokoyama, Masaki Takakuwa, Yasuki Shimoyama
  • Patent number: 5354629
    Abstract: The nonaqueous electrolyte battery of this invention is provided with a spiral electrode unit comprising a separator laminated between a cathode and an anode rolled into a spiral shape having anode around the outer perimeter. An anode terminal tab disconnects from the outermost one circumference of anode residue after discharge to prevent residual anode deposition on the cathode when power is overdrawn.
    Type: Grant
    Filed: October 9, 1992
    Date of Patent: October 11, 1994
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Akira Kuroda, Atsushi Yamano, Satoshi Narukawa, Yuichi Yokoyama
  • Patent number: 4540761
    Abstract: The oxygen-permeable hard contact lens of this invention produced by polymerizing in a composition composed of 30 to 50% by weight of an alkyl (meth)acrylate, 10 to 40% by weight of a fluorine-containing monomer, 10 to 35% by weight of a silicone (meth)acrylate, 5 to 15% by weight of an unsaturated carboxylic acid and 0.1 to 15% by weight of a di- or tri(meth)acrylate of a dihydric or higher hydric alcohol by raising a temperature continuously or stepwise from 40.degree. to 100.degree. C. and processing the resulting polymer into a lens shape by ordinary mechanical processing and polishing, is excellent in stain resistance, scratch resistance and hydrophilicity.
    Type: Grant
    Filed: March 19, 1984
    Date of Patent: September 10, 1985
    Assignee: Hoya Lens Corporation
    Inventors: Kazunori Kawamura, Shinichi Yamashita, Yuichi Yokoyama, Makoto Tsuchiya