Patents by Inventor Yasuhito Narushima

Yasuhito Narushima 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).

  • Publication number: 20200027732
    Abstract: A manufacturing method of monocrystalline silicon includes: disposing a flow regulator including a body in a form of an annular plate, provided under a heat shield, surrounding monocrystalline silicon; controlling an internal pressure of a chamber to 20 kPa or more during growth of monocrystalline silicon; keeping the flow regulator spaced from a dopant-added melt; and introducing inert gas into between the monocrystalline silicon and the heat shield to divide the inert gas into a first flow gas and a second flow gas.
    Type: Application
    Filed: November 14, 2017
    Publication date: January 23, 2020
    Applicant: SUMCO CORPORATION
    Inventors: Fukuo OGAWA, Yasuhito NARUSHIMA, Koichi MAEGAWA, Yasufumi KAWAKAMI
  • Publication number: 20190249331
    Abstract: A production method of a monocrystalline silicon includes: forming a shoulder of the monocrystalline silicon; and forming a straight body of the monocrystalline silicon. To form the shoulder, a crucible is heated such that a heating ratio, which is calculated by dividing a volume of heat from a lower heater by a volume of heat from an upper heater, increases from a predetermined value of 1 or more.
    Type: Application
    Filed: April 18, 2017
    Publication date: August 15, 2019
    Applicant: SUMCO CORPORATION
    Inventors: Yasuhito NARUSHIMA, Toshimichi KUBOTA
  • Patent number: 10329686
    Abstract: A manufacturing method of a monocrystal includes: a shoulder-formation step to form a shoulder of the monocrystal; and a straight-body-formation step to form a straight body of the monocrystal, in which, in the shoulder-formation step, providing that a distance from a lowermost portion inside the crucible to a top surface of the dopant-added melt is defined as H (mm) and a radius of the top surface of the dopant-added melt is defined as R (mm), the shoulder starts to be formed in a condition that a relationship of 0.4<H/R<0.78 is satisfied.
    Type: Grant
    Filed: November 17, 2015
    Date of Patent: June 25, 2019
    Assignee: SUMCO CORPORATION
    Inventors: Yasuhito Narushima, Toshimichi Kubota, Masayuki Uto
  • Publication number: 20190186042
    Abstract: A production method of a monocrystalline silicon includes: forming a shoulder of the monocrystalline silicon; and forming a straight body of the monocrystalline silicon. In forming the shoulder, the shoulder is formed such that a part of growth striations, which extend radially across the shoulder, has an outer end interrupted by another part of the growth striations not to reach a peripheral portion of the shoulder and that no remelt growth area with a height of 200 ?m or more in a growth direction is generated.
    Type: Application
    Filed: April 26, 2017
    Publication date: June 20, 2019
    Applicant: SUMCO CORPORATION
    Inventors: Yasuhito NARUSHIMA, Toshimichi KUBOTA
  • Patent number: 10294583
    Abstract: The sublimation speed of dopant can be precisely controlled without being influenced by a change over time of intra-furnace thermal environment. A dopant supply unit equipped with an accommodation chamber and a supply tube is provided. A sublimable dopant is accommodated. Upon sublimation of the dopant within the accommodation chamber, the sublimed dopant is introduced into a melt. The dopant within the accommodation chamber of the dopant supply unit is heated. The amount of heating by means of heating means is controlled so as to sublime the dopant at a desired sublimation speed. The dopant is supplied to the melt so that the dopant concentration until the first half of a straight body portion of the silicon single crystal is in the state of low concentration or non-addition.
    Type: Grant
    Filed: April 23, 2008
    Date of Patent: May 21, 2019
    Assignee: SUMCO TECHXIV CORPORATION
    Inventors: Yasuhito Narushima, Shinichi Kawazoe, Fukuo Ogawa, Masahiro Irokawa, Toshimichi Kubota
  • Patent number: 10233562
    Abstract: A manufacturing method of a single crystal uses a single-crystal pull-up apparatus includes: adding the red phosphorus to the silicon melt so that a resistivity of the single crystal falls in a range from 0.7 m?·cm to 0.9 m?·cm; subjecting an evaluation silicon wafer obtained from the single crystal to a heat treatment in which the evaluation silicon wafer is heated at 1200 degrees C. for 30 seconds in a hydrogen atmosphere; and pull-up the single crystal while appropriately controlling a period for a temperature of the single crystal to be in a range of 570±70 degrees C. so that the number of pits generated on the evaluation silicon wafer becomes 0.1/cm2 or less.
    Type: Grant
    Filed: April 15, 2014
    Date of Patent: March 19, 2019
    Assignee: SUMCO TECHXIV CORPORATION
    Inventors: Yasuhito Narushima, Toshimichi Kubota, Fukuo Ogawa, Masayuki Uto
  • Patent number: 10233564
    Abstract: A smonocrystalline silicon include a straight body formed without generating a remelt growth area of 200 ?m or more in a height in a growth direction. Growth striations, which are formed radially across the straight body, include a growth striation with an outer end interrupted by another growth striation not to reach a peripheral portion of the straight body. The remelt growth area has the growth striation with the interrupted outer end.
    Type: Grant
    Filed: October 2, 2017
    Date of Patent: March 19, 2019
    Assignee: SUMCO CORPORATION
    Inventors: Yasuhito Narushima, Shinichi Kawazoe, Fukuo Ogawa
  • Patent number: 10227710
    Abstract: A manufacturing method of a silicon monocrystal uses a monocrystal pulling-up apparatus including: a chamber; a crucible disposed in the chamber and configured to receive dopant-added melt; a pulling-up portion that pulls up a seed crystal after the seed crystal is in contact with the dopant-added melt; a cooler disposed above the crucible to cool a monocrystal that is being grown; and a magnetic field applying unit disposed outside the chamber to apply a horizontal magnetic field to the dopant-added melt. The method includes: during a formation of a shoulder of the silicon monocrystal, starting the formation while moving the cooler downward; stopping the cooler from moving downward at a stop position before a top of the shoulder reaches a level of a lower end of the cooler; and continuing the formation of the shoulder while the cooler is kept at the stop position.
    Type: Grant
    Filed: June 28, 2016
    Date of Patent: March 12, 2019
    Assignee: SUMCO TECHXIV CORPORATION
    Inventors: Yasuhito Narushima, Toshimichi Kubota, Masayuki Uto
  • Patent number: 10100429
    Abstract: A method for producing a single crystal includes: bringing a seed crystal into contact with a dopant-added melt, in which a red phosphorus is added to a silicon melt, such that a resistivity of the single crystal is 0.9 m?·cm or less and subsequently pulling up the seed crystal, to form a straight body of the single crystal; and withdrawing the single crystal from the dopant-added melt in a state that a temperature of an upper end of the straight body is 590 degrees C. or more.
    Type: Grant
    Filed: April 8, 2015
    Date of Patent: October 16, 2018
    Assignee: SUMCO CORPORATION
    Inventors: Yasuhito Narushima, Masayuki Uto, Toshimichi Kubota
  • Publication number: 20180094360
    Abstract: A smonocrystalline silicon include a straight body formed without generating a remelt growth area of 200 ?m or more in a height in a growth direction. Growth striations, which are formed radially across the straight body, include a growth striation with an outer end interrupted by another growth striation not to reach a peripheral portion of the straight body. The remelt growth area has the growth striation with the interrupted outer end.
    Type: Application
    Filed: October 2, 2017
    Publication date: April 5, 2018
    Applicant: SUMCO CORPORATION
    Inventors: Yasuhito NARUSHIMA, Shinichi KAWAZOE, Fukuo OGAWA
  • Publication number: 20170327966
    Abstract: A manufacturing method of a monocrystal includes: a shoulder-formation step to form a shoulder of the monocrystal; and a straight-body-formation step to form a straight body of the monocrystal, in which, in the shoulder-formation step, providing that a distance from a lowermost portion inside the crucible to a top surface of the dopant-added melt is defined as H (mm) and a radius of the top surface of the dopant-added melt is defined as R (mm), the shoulder starts to be formed in a condition that a relationship of 0.4<H/R<0.78 is satisfied.
    Type: Application
    Filed: November 17, 2015
    Publication date: November 16, 2017
    Applicant: SUMCO CORPORATION
    Inventors: Yasuhito NARUSHIMA, Toshimichi KUBOTA, Masayuki UTO
  • Publication number: 20170283980
    Abstract: A method for producing a single crystal includes: bringing a seed crystal into contact with a dopant-added melt, in which a red phosphorus is added to a silicon melt, such that a resistivity of the single crystal is 0.9 m?·cm or less and subsequently pulling up the seed crystal, to form a straight body of the single crystal; and withdrawing the single crystal from the dopant-added melt in a state that a temperature of an upper end of the straight body is 590 degrees C. or more.
    Type: Application
    Filed: April 8, 2015
    Publication date: October 5, 2017
    Applicant: SUMCO CORPORATION
    Inventors: Yasuhito NARUSHIMA, Masayuki UTO, Toshimichi KUBOTA
  • Publication number: 20170029975
    Abstract: A manufacturing method of a silicon monocrystal uses a monocrystal pulling-up apparatus including: a chamber; a crucible disposed in the chamber and configured to receive dopant-added melt; a pulling-up portion that pulls up a seed crystal after the seed crystal is in contact with the dopant-added melt; a cooler disposed above the crucible to cool a monocrystal that is being grown; and a magnetic field applying unit disposed outside the chamber to apply a horizontal magnetic field to the dopant-added melt.
    Type: Application
    Filed: June 28, 2016
    Publication date: February 2, 2017
    Applicant: SUMCO TECHXIV CORPORATION
    Inventors: Yasuhito NARUSHIMA, Toshimichi KUBOTA, Masayuki UTO
  • Publication number: 20160102418
    Abstract: A manufacturing method of a single crystal uses a single-crystal pull-up apparatus includes: adding the red phosphorus to the silicon melt so that a resistivity of the single crystal falls in a range from 0.7 m?·cm to 0.9 m?·cm; subjecting an evaluation silicon wafer obtained from the single crystal to a heat treatment in which the evaluation silicon wafer is heated at 1200 degrees C. for 30 seconds in a hydrogen atmosphere; and pull-up the single crystal while appropriately controlling a period for a temperature of the single crystal to be in a range of 570±70 degrees C. so that the number of pits generated on the evaluation silicon wafer becomes 0.1/cm2 or less.
    Type: Application
    Filed: April 15, 2014
    Publication date: April 14, 2016
    Applicant: SUMCO TECHXIV CORPORATION
    Inventors: Yasuhito NARUSHIMA, Toshimichi KUBOTA, Fukuo OGAWA, Masayuki UTO
  • Patent number: 9212431
    Abstract: A graphite member utilized in a pulling device for pulling a silicon single crystal is provided. An edge part of the graphite member is rounded off which is exposed to a reactive gas. The graphite member may comprise: a plate part having a thickness of ‘t’ wherein a curvature radius of ‘r’ satisfies the formula: t/8?r?t/4.
    Type: Grant
    Filed: September 28, 2007
    Date of Patent: December 15, 2015
    Assignee: SUMCO TECHXIV CORPORATION
    Inventors: Shinichi Kawazoe, Fukuo Ogawa, Yasuhito Narushima, Tsuneaki Tomonaga, Toshimichi Kubota
  • Patent number: 9074298
    Abstract: A process for production of a silicon ingot, by which a silicon ingot exhibiting a low resistivity even in the top portion can be produced. The process for the production of a silicon ingot includes withdrawing a silicon seed crystal from a silicon melt to grow a silicon single crystal, with the silicon seed crystal and the silicon melt containing dopants of the same kind. The process includes the dipping step of dipping a silicon seed crystal containing a dopant in a specific concentration in a silicon melt in such a manner that the temperature difference between both falls within the range of 50 to 97K, and the growing step of growing a silicon single crystal withdrawn after the dipping to form a silicon ingot, the growing step being conducted by using a single crystal puller provided with a thermal shield plate for shielding against radiant heat emitted from the silicon melt and controlling the distance between the thermal shield plate and the silicon melt within a specific range.
    Type: Grant
    Filed: August 11, 2009
    Date of Patent: July 7, 2015
    Assignees: SUMCO TECHXIV CORPORATION, SUMCO CORPORATION
    Inventors: Shinichi Kawazoe, Toshimichi Kubota, Fukuo Ogawa, Yasuhito Narushima
  • Patent number: 8961686
    Abstract: For manufacturing a monocrystal, a monocrystal pulling-up device controls pressure within a flow straightening cylinder to be from 33331 Pa to 79993 Pa and a flow velocity of inert gas in the cylinder to be from 0.06 m/sec to 0.31 m/sec (0.005 to 0.056 SL/min·cm2) during a post-addition-pre-growth period. By controlling the flow velocity of the inert gas to be in the above-described range during the post-addition-pre-growth period, the inert gas flows smoothly even when the pressure within the cylinder is relatively high. Evaporation of a volatile dopant because of a reverse flow of the inert gas can be restrained. The volatile dopant can be prevented from adhering to the flow straightening cylinder in an amorphous state, and the volatile dopant can be prevented from dropping into a melt or sticking on the melt while growing a crystal. Foulings can be easily removed.
    Type: Grant
    Filed: July 25, 2008
    Date of Patent: February 24, 2015
    Assignee: Sumco Techxiv Corporation
    Inventors: Shinichi Kawazoe, Fukuo Ogawa, Yasuhito Narushima, Toshimichi Kubota
  • Patent number: 8920561
    Abstract: A silicon single crystal pull-up apparatus includes a pull-up furnace, a sample chamber in which a sublimable dopant is housed, a sample tube which can be raised and lowered between the interior of the sample chamber and the interior of the pull-up furnace, a raising and lowering means for raising and lowering the sample tube, a supply pipe which is installed inside the pull-up furnace and supplies the sublimable dopant to a melt, and a connection means for connecting the sample tube and the supply pipe. The connection means is constructed from a ball joint structure comprising a convex member which projects from one end of the sample tube and a concave member which is provided at one end of the supply pipe and is formed to be engageable with the convex member. The contact surfaces of the convex member and the concave member are formed to be curved surfaces.
    Type: Grant
    Filed: July 28, 2009
    Date of Patent: December 30, 2014
    Assignee: Sumco Techxiv Corporation
    Inventors: Yasuhito Narushima, Shinichi Kawazoe, Fukuo Ogawa, Toshimichi Kubota, Tomohiro Fukuda
  • Patent number: 8888911
    Abstract: The present invention provides a technique which enables production of single crystal silicon having relatively low resistivity by preventing cell growth during crystal growth from occurring, especially in a case where a relatively large amount of dopant is added to a molten silicon raw material. Specifically, the present invention provides a method of producing single crystal silicon by the Czochralski process, comprising producing single crystal silicon having relatively low resistivity by controlling a height of a solid-liquid interface when the single crystal silicon is pulled up.
    Type: Grant
    Filed: September 3, 2010
    Date of Patent: November 18, 2014
    Assignee: Sumco Techxiv Corporation
    Inventors: Masayuki Uto, Tuneaki Tomonaga, Toshimichi Kubota, Fukuo Ogawa, Yasuhito Narushima
  • Patent number: 8871023
    Abstract: A silicon single crystal pull-up apparatus is provided with a chamber into which an inert gas is introduced; a crucible that supports a silicon melt within the chamber; a heater that heats the silicon melt in the crucible; a lifting device for lifting and lowering the crucible; a thermal radiation shield disposed above the crucible; a cylindrical purging tube that is provided inside the thermal radiation shield so as to straighten the inert gas; a CCD camera that photographs the mirror image of the thermal radiation shield reflected on the liquid surface of the silicon melt through the purging tube; a liquid surface level calculator that calculates the liquid surface level of the silicon melt from the position of the mirror image photographed by the camera; and a conversion table creator that creates a conversion table representing a relationship between the liquid surface level of the silicon melt and the mirror image position obtained.
    Type: Grant
    Filed: April 11, 2011
    Date of Patent: October 28, 2014
    Assignee: Sumco Corporation
    Inventors: Keiichi Takanashi, Kengo Hayashi, Yasuhito Narushima