Patents by Inventor Seiichiro Ohtsuka

Seiichiro Ohtsuka 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: 5868835
    Abstract: A recharger system including a feeder and a feed conduit recharge polycrystalline silicon granules into a crucible after a run or operation of growing a single crystal silicon rod by the Czochralski method, thereby to prepare for a next run of crystal growing. The amount of holdup or backed-up supply of the silicon granules in the feed conduit is detected by a sensor provided on the feed conduit. A smooth and high-rate feed of the silicon granules is ensured by controlling the feed rate of the silicon granules from the feeder to the feed conduit and/or a descending velocity of the crucible by signals generated in the sensor as a function of the amount of the holdup or backed-up supply in the feed conduit.
    Type: Grant
    Filed: August 7, 1997
    Date of Patent: February 9, 1999
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Naoki Nagai, Michiaki Oda, Seiichiro Ohtsuka, Isamu Harada
  • Patent number: 5690733
    Abstract: A recharger system including a feeder and a feed conduit recharge polycrystalline silicon granules into a crucible after a run or operation of growing a single crystal silicon rod by the Czochralski method, thereby to prepare for a next run of crystal growing. The amount of holdup or backed-up supply of the silicon granules in the feed conduit is detected by a sensor provided on the feed conduit. A smooth and high-rate feed of the silicon granules is ensured by controlling the feed rate of the silicon granules from the feeder to the feed conduit and/or a descending velocity of the crucible by signals generated in the sensor as a function of the amount of the holdup or backed-up supply in the feed conduit.
    Type: Grant
    Filed: November 9, 1995
    Date of Patent: November 25, 1997
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Naoki Nagai, Michiaki Oda, Seiichiro Ohtsuka, Isamu Harada
  • Patent number: 5129986
    Abstract: A method for controlling a specific resistance of a single crystal in a Czochralski-method type single crystal pulling apparatus having a hermetical chamber in which the single crystal is pulled up from a polycrystal melt and an inert gas supply and exhaust system by means of which an inert gas is supplied to the hermetical chamber and exhausted therefrom; the method being characterized in that the pneumatic pressure in the hermetical chamber and the supply rate of the inert gas are controlled in accordance with a prepared control pattern with respect to the passage of pulling time.
    Type: Grant
    Filed: November 16, 1990
    Date of Patent: July 14, 1992
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Hidetoshi Seki, Seiichiro Ohtsuka, Masahiko Baba
  • Patent number: 5106593
    Abstract: An apparatus for producing a single crystal grown by Czochralski method includes a winding drum disposed in a case for winding up and down a flexible pull wire, a power transmission mechanism for driving the winding drum, and a bearing unit for rotatably supporting the winding drum. The power transmission mechanism and the bearing unit are disposed outside the case and isolated from the furnace atmosphere surrounding the winding drum and the pull wire in the case. With this construction, metallic dust produced by abrasion from the power transmission mechanism and the bearing unit has no influence on the condition of the furnace atmosphere and hence the quality of a single crystal being pulled upwardly by the pull wire.
    Type: Grant
    Filed: December 21, 1990
    Date of Patent: April 21, 1992
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Koji Mizuishi, Michiaki Oda, Yasushi Nakamura, Seiichiro Ohtsuka, Atsushi Shiozawa, Fumio Yamada, Masahiro Mashimo, Tooru Ohara, Eizi Namiki
  • Patent number: 5089239
    Abstract: A single crystal pulling apparatus having a wire which is used to pull a crystal is provided with a novel wire vibration prevention mechanism. The wire vibration prevention mechanism includes wire restriction devices which restrict the movement of the wire to movement in the vertical direction. The wire restriction devices may be mechanically driven in the horizontal direction in order to center the pulled crystal. The wire restriction devices are driven by pneumatic air cylinders. Use of the wire vibration prevention mechanism avoids the formation of deformed growth of the pulled crystal and thus reduces the occurrence of dislocations in the pulled crystal.
    Type: Grant
    Filed: April 17, 1990
    Date of Patent: February 18, 1992
    Assignee: Shin-Etsu Handotai Company Limited
    Inventors: Koji Mizuishi, Isamu Harada, Yasushi Nakamura, Michiaki Oda, Seiichiro Ohtsuka, Yoshihiro Hirano, Masahiko Urano