Patents by Inventor Koichi MAEGAWA

Koichi MAEGAWA 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: 12116691
    Abstract: A production method of monocrystalline silicon includes: growing the monocrystalline silicon having a straight-body diameter in a range from 301 mm to 330 mm that is pulled up through a Czochralski process from a silicon melt including a dopant in a form of arsenic; controlling a resistivity of the monocrystalline silicon at the straight-body start point to fall within a range from 2.50 m?cm to 2.90 m?cm; and subsequently sequentially decreasing the resistivity of the monocrystalline silicon to fall within a range from 1.6 m?cm to 2.0 m?cm at a part of the monocrystalline silicon.
    Type: Grant
    Filed: October 3, 2023
    Date of Patent: October 15, 2024
    Assignee: SUMCO CORPORATION
    Inventors: Yasufumi Kawakami, Koichi Maegawa
  • Publication number: 20240026564
    Abstract: A production method of monocrystalline silicon includes: growing the monocrystalline silicon having a straight-body diameter in a range from 301 mm to 330 mm that is pulled up through a Czochralski process from a silicon melt including a dopant in a form of arsenic; controlling a resistivity of the monocrystalline silicon at the straight-body start point to fall within a range from 2.50 m?cm to 2.90 m?cm; and subsequently sequentially decreasing the resistivity of the monocrystalline silicon to fall within a range from 1.6 m?cm to 2.0 m?cm at a part of the monocrystalline silicon.
    Type: Application
    Filed: October 3, 2023
    Publication date: January 25, 2024
    Applicant: SUMCO CORPORATION
    Inventors: Yasufumi KAWAKAMI, Koichi MAEGAWA
  • Patent number: 11814745
    Abstract: A production method of monocrystalline silicon includes: growing the monocrystalline silicon having a straight-body diameter in a range from 301 mm to 330 mm that is pulled up through a Czochralski process from a silicon melt including a dopant in a form of red phosphorus; controlling a resistivity of the monocrystalline silicon at a straight-body start point to fall within a range from 1.20 m?cm to 1.35 m?cm; and subsequently sequentially decreasing the resistivity of the monocrystalline silicon to fall within a range from 0.7 m?cm to 1.0 m?cm at a part of the monocrystalline silicon.
    Type: Grant
    Filed: June 15, 2018
    Date of Patent: November 14, 2023
    Assignee: SUMCO CORPORATION
    Inventors: Yasufumi Kawakami, Koichi Maegawa
  • 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
  • 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
  • Patent number: 11639560
    Abstract: A deposit removing device disclosed herein removes a deposit that adheres to an exhaust pipe through which gas is exhausted from a chamber that manufactures a semiconductor crystal. The deposit removing device includes: a valve that opens and closes an exhaust outlet that communicates with the exhaust pipe; a sealing cover and a fixed table configured to store the valve, into which an inert gas is introduceable, and configured to isolate the exhaust outlet from the outside; and an exhaust outlet opening/closing portion that includes a cylinder for driving the valve and a cylinder for driving the sealing cover or the fixed table. The cylinder drives the valve to open and close the exhaust outlet, and the cylinder drives the sealing cover or the fixed table to introduce the atmosphere into the sealing cover.
    Type: Grant
    Filed: May 28, 2020
    Date of Patent: May 2, 2023
    Assignee: SUMCO CORPORATION
    Inventors: Fukuo Ogawa, Takuya Yotsui, Koichi Maegawa
  • Patent number: 11426775
    Abstract: A cleaning method includes a first removal step of causing an inert gas to which a pulsation is applied to flow into an exhaust pipe after a silicon single crystal doped with an n-type dopant is produced, to peel and remove a deposit; and a second removal step of causing an atmospheric air to which no pulsation is applied to flow into the exhaust pipe through a chamber to burn a part of the deposit with the atmospheric air, the part being not removable in the first removal step, and peel and remove a burned substance of the deposit.
    Type: Grant
    Filed: November 16, 2018
    Date of Patent: August 30, 2022
    Assignee: SUMCO CORPORATION
    Inventors: Koichi Maegawa, Takuya Yotsui, Satoru Hamakawa
  • Publication number: 20220267929
    Abstract: A deposit removing device disclosed herein removes a deposit that adheres to an exhaust pipe through which gas is exhausted from a chamber that manufactures a semiconductor crystal. The deposit removing device includes: a valve that opens and closes an exhaust outlet that communicates with the exhaust pipe; a sealing cover and a fixed table configured to store the valve, into which an inert gas is introduceable, and configured to isolate the exhaust outlet from the outside; and an exhaust outlet opening/closing portion that includes a cylinder for driving the valve and a cylinder for driving the sealing cover or the fixed table. The cylinder drives the valve to open and close the exhaust outlet, and the cylinder drives the sealing cover or the fixed table to introduce the atmosphere into the sealing cover.
    Type: Application
    Filed: May 28, 2020
    Publication date: August 25, 2022
    Applicant: SUMCO CORPORATION
    Inventors: Fukuo OGAWA, Takuya YOTSUI, Koichi MAEGAWA
  • 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: 20210040642
    Abstract: A production method of monocrystalline silicon includes: growing the monocrystalline silicon having a straight-body diameter in a range from 301 mm to 330 mm that is pulled up through a Czochralski process from a silicon melt including a dopant in a form of red phosphorus; controlling a resistivity of the monocrystalline silicon at a straight-body start point to fall within a range from 1.20 m?cm to 1.35 m?cm; and subsequently sequentially decreasing the resistivity of the monocrystalline silicon to fall within a range from 0.7 m?cm to 1.0 m?cm at a part of the monocrystalline silicon.
    Type: Application
    Filed: June 15, 2018
    Publication date: February 11, 2021
    Applicant: SUMCO CORPORATION
    Inventors: Yasufumi KAWAKAMI, Koichi MAEGAWA
  • 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
  • Publication number: 20200346258
    Abstract: A cleaning method includes a first removal step of causing an inert gas to which a pulsation is applied to flow into an exhaust pipe after a silicon single crystal doped with an n-type dopant is produced, to peel and remove a deposit; and a second removal step of causing an atmospheric air to which no pulsation is applied to flow into the exhaust pipe through a chamber to burn a part of the deposit with the atmospheric air, the part being not removable in the first removal step, and peel and remove a burned substance of the deposit.
    Type: Application
    Filed: November 16, 2018
    Publication date: November 5, 2020
    Applicant: SUMCO CORPORATION
    Inventors: Koichi MAEGAWA, Takuya YOTSUI, Satoru HAMAKAWA
  • 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: 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
  • 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
  • Patent number: 9553221
    Abstract: Disclosed is an electromagnetic casting method of polycrystalline silicon which is characterized in that polycrystalline silicon is continuously cast by charging silicon raw materials into a bottomless cold mold, melting the silicon raw materials using electromagnetic induction heating, and pulling down the molten silicon to solidify it, wherein the depth of solid-liquid interface before the start of the final solidification process is decreased by reducing a pull down rate of ingot in a final phase of steady-state casting. By adopting the method, the region of precipitation of foreign substances in the finally solidified portion of ingot can be reduced and cracking generation can be prevented upon production of a polycrystalline silicon as a substrate material for a solar cell.
    Type: Grant
    Filed: March 18, 2013
    Date of Patent: January 24, 2017
    Assignee: SUMCO CORPORATION
    Inventors: Koichi Maegawa, Tomohiro Onizuka, Mitsuo Yoshihara
  • Patent number: 9080814
    Abstract: Provided is a continuous casting method of a silicon ingot for continuously casting the silicon ingot by arranging, inside an induction coil, a bottomless cold crucible having a part along an axial direction that is circumferentially divided into a plurality of strip elements, forming molten silicon inside the cold crucible through electromagnetic induction heating by the induction coil, and solidifying the molten silicon while pulling it down from the cold crucible, wherein as the cold crucible, used is a cold crucible with Ni—B alloy plating on a portion in the inner surface thereof that faces the outer side surface of the molten silicon and the outer surface of the silicon ingot. The method can reduce the damage to the inner surface of the cold crucible, in addition to the contamination of cast ingots with impurities.
    Type: Grant
    Filed: March 11, 2013
    Date of Patent: July 14, 2015
    Assignee: SUMCO CORPORATION
    Inventors: Mitsuo Yoshihara, Koichi Maegawa, Shinya Fukushima