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: 20240003044
    Abstract: There is provided a growing method of monocrystalline silicon including: pulling up monocrystalline silicon from a dopant-added melt in which a dopant is added to a silicon melt and growing the monocrystalline silicon according to Czochralski process, in which the monocrystalline silicon is grown by calculating a critical CV value, which is a product of a dopant concentration C and a pull-up speed V at a point of time when an abnormal growth occurred in the monocrystalline silicon; and controlling at least one of the dopant concentration C or the pull-up speed V to make a CV value, which is a product of the dopant concentration C and the pull-up speed V at the point of time, below the critical CV value.
    Type: Application
    Filed: December 2, 2021
    Publication date: January 4, 2024
    Applicant: SUMCO CORPORATION
    Inventors: Takashi IZEKI, Yasuhito NARUSHIMA
  • Publication number: 20230295835
    Abstract: A method for producing an n-type monocrystalline silicon that includes pulling up a monocrystalline silicon from a silicon melt containing a main dopant in a form of red phosphorus to grow the monocrystalline silicon. The monocrystalline silicon exhibits an electrical resistivity ranging from 1.7 m?cm to 2.0 m?cm, and is pulled up using a quartz crucible whose inner diameter ranges from 1.7-fold to 2.0-fold relative to a straight-body diameter of the monocrystalline silicon.
    Type: Application
    Filed: May 25, 2023
    Publication date: September 21, 2023
    Applicant: SUMCO CORPORATION
    Inventors: Koichi MAEGAWA, Yasuhito NARUSHIMA, Yasufumi KAWAKAMI, Fukuo OGAWA, Ayumi KIHARA
  • Publication number: 20230243066
    Abstract: A semiconductor wafer including a single crystal doped with a dopant, wherein a resistivity of the wafer is 0.7 m?-cm or less, and wherein a striation height of the wafer is 6 mm or more. The resistivity of the wafer may be 0.8 m?-cm or less, and the striation height may be 13 mm or more. The resistivity of the wafer may be 0.7 m?-cm or less, and the striation may be 22 mm or more. Example features relate to a method of making a semiconductor wafer that includes adding a dopant to a silicon melt, rotationally pulling a crystal from the silicon melt, and applying a magnetic field of 3000 G or more such that the semiconductor wafer has a resistivity that is equal to or less than 0.8 m?-cm and a striation height that is equal to or more than 13 mm.
    Type: Application
    Filed: January 25, 2023
    Publication date: August 3, 2023
    Applicant: SUMCO CORPORATION
    Inventors: Yasuhito NARUSHIMA, Masayuki UTO
  • Patent number: 11702760
    Abstract: In a producing method of an n-type monocrystalline silicon by pulling up a monocrystalline silicon from a silicon melt containing a main dopant in a form of red phosphorus to grow the monocrystalline silicon, the monocrystalline silicon exhibiting an electrical resistivity ranging from 0.5 m?cm to 1.0 m?cm is pulled up using a quartz crucible whose inner diameter ranges from 1.7-fold to 2.3-fold relative to a straight-body diameter of the monocrystalline silicon.
    Type: Grant
    Filed: March 20, 2018
    Date of Patent: July 18, 2023
    Assignee: SUMCO CORPORATION
    Inventors: Koichi Maegawa, Yasuhito Narushima, Yasufumi Kawakami, Fukuo Ogawa, Ayumi Kihara
  • Publication number: 20230133472
    Abstract: A silicon wafer is provided in which a dopant is phosphorus, resistivity is from 0.5 m?·cm to 1.2 m?·cm, and carbon concentration is 3.0×1016 atoms/cm3 or more. The carbon concentration is decreased by 10% or more near a surface of the silicon wafer compared with a center-depth of the silicon wafer.
    Type: Application
    Filed: June 29, 2022
    Publication date: May 4, 2023
    Applicant: SUMCO CORPORATION
    Inventors: Kohtaroh KOGA, Yasuhito NARUSHIMA, Naoya NONAKA, Toshiaki ONO, Masataka HOURAI
  • Publication number: 20230132859
    Abstract: A silicon wafer is provided in which a dopant is phosphorus, resistivity is 1.2 m?·cm or less, and carbon concentration is 3.5×1015 atoms/cm3 or more. The carbon concentration is decreased by 10% or more near a surface of the silicon wafer compared with a center-depth of the silicon wafer.
    Type: Application
    Filed: November 3, 2022
    Publication date: May 4, 2023
    Applicant: SUMCO CORPORATION
    Inventors: Kohtaroh KOGA, Yasuhito NARUSHIMA, Naoya NONAKA
  • Patent number: 11598023
    Abstract: A semiconductor wafer including a single crystal doped with a dopant, wherein a resistivity of the wafer is 0.7 m?-cm or less, and wherein a striation height of the wafer is 6 mm or more. The resistivity of the wafer may be 0.8 m?-cm or less, and the striation height may be 13 mm or more. The resistivity of the wafer may be 0.7 m?-cm or less, and the striation may be 22 mm or more. Example features relate to a method of making a semiconductor wafer that includes adding a dopant to a silicon melt, rotationally pulling a crystal from the silicon melt, and applying a magnetic field of 3000 G or more such that the semiconductor wafer has a resistivity that is equal to or less than 0.8 m?-cm and a striation height that is equal to or more than 13 mm.
    Type: Grant
    Filed: June 29, 2020
    Date of Patent: March 7, 2023
    Assignee: SUMCO CORPORATION
    Inventors: Yasuhito Narushima, Masayuki Uto
  • Publication number: 20230031070
    Abstract: A monocrystalline silicon includes a shoulder, a straight body, and a tail. The straight body includes: a first straight body having a first diameter d1; and a second straight body provided closer to the shoulder than the first straight body is and having a second diameter d2 larger than the first diameter d1 by from 3.5% to 15%. Firstly, a resistivity at a start point of the straight body connected to the shoulder is set to a first resistivity. Subsequently, the monocrystalline silicon is pulled up and grown to form the first straight body, and a resistivity at a start point of the first straight body is set to a second resistivity lower than the first resistivity.
    Type: Application
    Filed: December 21, 2020
    Publication date: February 2, 2023
    Applicant: SUMCO CORPORATION
    Inventors: Takashi IZEKI, Yasuhito NARUSHIMA
  • Patent number: 11377755
    Abstract: An n-type silicon single crystal production method of pulling up a silicon single crystal from a silicon melt containing red phosphorus as a principal dopant and growing the silicon single crystal by the Czochralski process, the method including: controlling electrical resistivity at a start position of a straight body portion of the silicon single crystal to 0.80 m?cm or more and 1.05 m?cm or less; and sequentially lowering the electrical resistivity of the silicon single crystal as the silicon single crystal is up and grown, thereby adjusting electrical resistivity of a part of the silicon single crystal to 0.5 m?m or more and less than 0.6 m?cm.
    Type: Grant
    Filed: March 29, 2018
    Date of Patent: July 5, 2022
    Assignee: SUMCO CORPORATION
    Inventors: Koichi Maegawa, Yasuhito Narushima, Yasufumi Kawakami, Fukuo Ogawa, Yuuji Tsutsumi
  • Patent number: 11242617
    Abstract: A silicon single crystal production method includes pulling up and growing a silicon single crystal from silicon melt containing red phosphorus as a dopant by Czochralski process. The silicon single crystal is intended for a 200-mm-diameter wafer. The silicon single crystal includes a straight body with a diameter in a range from 201 mm to 230 mm. The straight body includes a straight-body start portion with an electrical resistivity in a range from 0.8 m?cm to 1.2 m?cm. A crystal rotation speed of the silicon single crystal is controlled to fall within a range from 17 rpm to 40 rpm for at least part of a shoulder-formation step for the silicon single crystal.
    Type: Grant
    Filed: October 30, 2017
    Date of Patent: February 8, 2022
    Assignee: SUMCO CORPORATION
    Inventors: Koichi Maegawa, Yasuhito Narushima, Yasufumi Kawakami, Fukuo Ogawa
  • Publication number: 20210404087
    Abstract: A semiconductor wafer including a single crystal doped with a dopant, wherein a resistivity of the wafer is 0.7 m?-cm or less, and wherein a striation height of the wafer is 6 mm or more. The resistivity of the wafer may be 0.8 m?-cm or less, and the striation height may be 13 mm or more. The resistivity of the wafer may be 0.7 m?-cm or less, and the striation may be 22 mm or more. Example features relate to a method of making a semiconductor wafer that includes adding a dopant to a silicon melt, rotationally pulling a crystal from the silicon melt, and applying a magnetic field of 3000 G or more such that the semiconductor wafer has a resistivity that is equal to or less than 0.8 m?-cm and a striation height that is equal to or more than 13 mm.
    Type: Application
    Filed: June 29, 2020
    Publication date: December 30, 2021
    Applicant: SUMCO CORPORATION
    Inventors: Yasuhito NARUSHIMA, Masayuki UTO
  • Patent number: 11047065
    Abstract: A method of producing a monocrystalline silicon uses a monocrystal pull-up apparatus including a crucible, a crucible driver, a pull-up portion, a heat shield having a circular hollow cylindrical lower end portion, and a chamber. The heat shield satisfies a formula (1) below in growing the monocrystalline silicon, R?1.27×C??(1) where C represents a radius (mm) of a straight body of the monocrystalline silicon, and R represents an inner radius (mm) at the lower end portion of the heat shield.
    Type: Grant
    Filed: October 12, 2017
    Date of Patent: June 29, 2021
    Assignee: SUMCO CORPORATION
    Inventors: Yasuhito Narushima, Masayuki Uto
  • Patent number: 10982350
    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: Grant
    Filed: April 26, 2017
    Date of Patent: April 20, 2021
    Assignee: SUMCO CORPORATION
    Inventors: Yasuhito Narushima, Toshimichi Kubota
  • Patent number: 10916425
    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: Grant
    Filed: November 14, 2017
    Date of Patent: February 9, 2021
    Assignee: SUMCO CORPORATION
    Inventors: Fukuo Ogawa, Yasuhito Narushima, Koichi Maegawa, Yasufumi Kawakami
  • Patent number: 10895018
    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: Grant
    Filed: April 18, 2017
    Date of Patent: January 19, 2021
    Assignee: SUMCO CORPORATION
    Inventors: Yasuhito Narushima, Toshimichi Kubota
  • Publication number: 20200224329
    Abstract: An n-type silicon single crystal production method of pulling up a silicon single crystal from a silicon melt containing red phosphorus as a principal dopant and growing the silicon single crystal by the Czochralski process, the method including: controlling electrical resistivity at a start position of a straight body portion of the silicon single crystal to 0.80 m?cm or more and 1.05 m?cm or less; and sequentially lowering the electrical resistivity of the silicon single crystal as the silicon single crystal is up and grown, thereby adjusting electrical resistivity of a part of the silicon single crystal to 0.5 m?m or more and less than 0.6 m?cm.
    Type: Application
    Filed: March 29, 2018
    Publication date: July 16, 2020
    Applicant: SUMCO CORPORATION
    Inventors: Koichi MAEGAWA, Yasuhito NARUSHIMA, Yasufumi KAWAKAMI, Fukuo OGAWA, Yuuji TSUTSUMI
  • Publication number: 20200141024
    Abstract: In a producing method of an n-type monocrystalline silicon by pulling up a monocrystalline silicon from a silicon melt containing a main dopant in a form of red phosphorus to grow the monocrystalline silicon, the monocrystalline silicon exhibiting an electrical resistivity ranging from 0.5 m?cm to 1.0 m?cm is pulled up using a quartz crucible whose inner diameter ranges from 1.7-fold to 2.3-fold relative to a straight-body diameter of the monocrystalline silicon.
    Type: Application
    Filed: March 20, 2018
    Publication date: May 7, 2020
    Applicant: SUMCO CORPORATION
    Inventors: Koichi MAEGAWA, Yasuhito NARUSHIMA, Yasufumi KAWAKAMI, Fukuo OGAWA, Ayumi KIHARA
  • Publication number: 20200135460
    Abstract: A production method of a monocrystalline silicon includes adding red phosphorus in a silicon melt so that an electrical resistivity of the monocrystalline silicon falls in a range of 0.5 m?·cm or more and less than 0.7 m?·cm; and pulling up the monocrystalline silicon so that a time for a temperature of at least a part of a straight body of the monocrystalline silicon to be within a range of 570 degrees C. 70 degrees C. is in a range from 10 minutes to 50 minutes.
    Type: Application
    Filed: April 12, 2018
    Publication date: April 30, 2020
    Applicant: SUMCO CORPORATION
    Inventors: Yasuhito NARUSHIMA, Koichi MAEGAWA, Fukuo OGAWA, Yasufumi KAWAKAMI
  • Publication number: 20200115821
    Abstract: A method of producing a monocrystalline silicon uses a monocrystal pull-up apparatus including a crucible, a crucible driver, a pull-up portion, a heat shield having a circular hollow cylindrical lower end portion, and a chamber. The heat shield satisfies a formula (1) below in growing the monocrystalline silicon, R?1.27×C??(1) where C represents a radius (mm) of a straight body of the monocrystalline silicon, and R represents an inner radius (mm) at the lower end portion of the heat shield.
    Type: Application
    Filed: October 12, 2017
    Publication date: April 16, 2020
    Applicant: SUMCO CORPORATION
    Inventors: Yasuhito NARUSHIMA, Masayuki UTO
  • Publication number: 20200087814
    Abstract: A silicon single crystal production method includes pulling up and growing a silicon single crystal from silicon melt containing red phosphorus as a dopant by Czochralski process. The silicon single crystal is intended for a 200-mm-diameter wafer. The silicon single crystal includes a straight body with a diameter in a range from 201 mm to 230 mm. The straight body includes a straight-body start portion with an electrical resistivity in a range from 0.8 m?cm to 1.2 m?cm. A crystal rotation speed of the silicon single crystal is controlled to fall within a range from 17 rpm to 40 rpm for at least part of a shoulder-formation step for the silicon single crystal.
    Type: Application
    Filed: October 30, 2017
    Publication date: March 19, 2020
    Applicant: SUMCO CORPORATION
    Inventors: Koichi MAEGAWA, Yasuhito NARUSHIMA, Yasufumi KAWAKAMI, Fukuo OGAWA