Patents by Inventor Ryoya Terakawa

Ryoya Terakawa 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: 20240025008
    Abstract: A method of polishing a silicon wafer, including a final polishing step including a pre-stage polishing step and a subsequent finish polishing step. The finish polishing step in the final polishing step includes a finish slurry polishing step using a polishing solution having an abrasive grain density of 1×1013/cm3 or more as the second polishing solution; and a pre-polishing step using a polishing solution having an abrasive grain density of 1×1010/cm3 or less as the second polishing solution, the pre-polishing step being performed prior to the finish slurry polishing step. A method of producing a silicon wafer, including the steps of: forming a notch portion on a periphery of a single crystal silicon ingot grown by the Czochralski process; slicing the ingot to obtain a silicon wafer; and subjecting the resulting silicon wafer to the above method of polishing a silicon wafer.
    Type: Application
    Filed: August 25, 2021
    Publication date: January 25, 2024
    Applicant: SUMCO CORPORATION
    Inventors: Masahiro MURAKAMI, Ryoya TERAKAWA
  • Publication number: 20230033545
    Abstract: Provided is a method of transferring a semiconductor wafer to a single-side polishing apparatus without forming scratches on the surface of the semiconductor wafer. The method includes: starting to splay the liquid from each spray hole; placing the semiconductor wafer on the retainer portion to hold a surface of the semiconductor wafer by suction without contact, and raising the tray to attach the semiconductor wafer to the polishing head, wherein a period of time from a point at which the semiconductor wafer is held by the retainer portion to a point at which the attaching of the semiconductor wafer W to the polishing head is completed is 5 s or more, or wherein a ratio of a total area of the protrusions to an area of the semiconductor wafer is 15% or more.
    Type: Application
    Filed: October 13, 2020
    Publication date: February 2, 2023
    Applicant: SUMCO CORPORATION
    Inventor: Ryoya TERAKAWA
  • Patent number: 11554458
    Abstract: A polishing head of a wafer polishing apparatus is provided with: a membrane head that can independently control a center control pressure pressing a center portion of a wafer, and an outer periphery control pressure pressing an outer peripheral portion of the wafer; an outer ring integrated with the membrane head so as to configure the outer peripheral portion of the membrane head; and a contact type retainer ring provided outside the membrane head. The membrane head has a central pressure chamber of a single compartment structure that controls the center control pressure, and an outer peripheral pressure chamber that is provided above the central pressure chamber, and that controls the outer periphery control pressure. A position of a lower end of the outer ring reaches at least a position of an inner bottom surface of the central pressure chamber.
    Type: Grant
    Filed: February 13, 2019
    Date of Patent: January 17, 2023
    Assignee: SUMCO CORPORATION
    Inventors: Yuki Nakano, Katsuhisa Sugimori, Kazuaki Kozasa, Jiro Kajiwara, Katsutoshi Yamamoto, Takayuki Kihara, Ryoya Terakawa
  • Publication number: 20220161388
    Abstract: A polishing head includes a first ring-shaped member having an opening; a plate-shaped member that closes the opening on an upper side of the first ring-shaped member; a membrane that closes the opening on a lower side of the first ring-shaped member; a back pad adhered to a lower surface of the membrane; and a second ring-shaped member located below the back pad and having an opening that holds a polishing target workpiece. A space formed by closing the opening of the first ring-shaped member by the plate-shaped member and the membrane includes: a central region; and an outer peripheral region partitioned from the central region by a partition, and an inner peripheral edge region of the second ring-shaped member is located vertically below an outer peripheral edge of the outer peripheral region. A polishing apparatus includes the polishing head, and is used in a method of manufacturing a semiconductor wafer.
    Type: Application
    Filed: December 27, 2019
    Publication date: May 26, 2022
    Applicant: SUMCO CORPORATION
    Inventors: Yuki NAKANO, Ryoya TERAKAWA, Takayuki KIHARA, Hiroki OTA
  • Publication number: 20210331285
    Abstract: A polishing head of a wafer polishing apparatus is provided with: a membrane head that can independently control a center control pressure pressing a center portion of a wafer, and an outer periphery control pressure pressing an outer peripheral portion of the wafer; an outer ring integrated with the membrane head so as to configure the outer peripheral portion of the membrane head; and a contact type retainer ring provided outside the membrane head. The membrane head has a central pressure chamber of a single compartment structure that controls the center control pressure, and an outer peripheral pressure chamber that is provided above the central pressure chamber, and that controls the outer periphery control pressure. A position of a lower end of the outer ring reaches at least a position of an inner bottom surface of the central pressure chamber.
    Type: Application
    Filed: February 13, 2019
    Publication date: October 28, 2021
    Applicant: SUMCO CORPORATION
    Inventors: Yuki NAKANO, Katsuhisa SUGIMORI, Kazuaki KOZASA, Jiro KAJIWARA, Katsutoshi YAMAMOTO, Takayuki KIHARA, Ryoya TERAKAWA
  • Patent number: 10744616
    Abstract: A wafer polishing method of polishing one surface of a wafer by rotating a rotating platen to which a polishing pad is affixed and a pressurizing head while supplying slurry onto the rotating platen and pressurizing/holding the wafer on the polishing pad with the pressurizing head, the method including: calculating an F/T value by monitoring a load current value F of a motor for rotating the rotating platen and a surface temperature T of the polishing pad during the wafer polishing; and controlling at least one of the rotation speed of the rotating platen and the polishing pressure of the pressurizing head based on the calculated F/T value.
    Type: Grant
    Filed: November 4, 2016
    Date of Patent: August 18, 2020
    Assignee: SUMCO CORPORATION
    Inventors: Tomonori Kawasaki, Ryoya Terakawa
  • Publication number: 20200258735
    Abstract: A wafer polishing method according to the present invention is provided with: a first polishing step (step S1) of polishing a wafer using a polishing head of an independent pressurizing system having a retainer ring capable of performing pressing operation independently of a wafer pressurizing mechanism; and a second polishing step (step S3) of polishing the wafer that has been polished in the first polishing step using a polishing head of a fixed pressurizing system having a retainer ring fixed to the wafer pressurizing mechanism.
    Type: Application
    Filed: November 4, 2016
    Publication date: August 13, 2020
    Applicant: SUMCO CORPORATION
    Inventors: Takashi NISHITANI, Ryuichi TANIMOTO, Ryoya TERAKAWA
  • Patent number: 10710209
    Abstract: A wafer polishing apparatus is provided with a rotating platen to which a polishing pad is affixed and a polishing head that holds a wafer placed on the polishing pad while pressing the wafer. The polishing head has a membrane that contacts the upper surface of the wafer and applying a pressing force thereto and a support plate that supports the membrane. The membrane has a main surface part facing the bottom surface of the support plate and a side surface part facing the outer peripheral edge surface of the support plate. The vertical tension due to the side surface part of the membrane is larger than the lateral tension due to the main surface part of the membrane.
    Type: Grant
    Filed: October 12, 2016
    Date of Patent: July 14, 2020
    Assignee: SUMCO CORPORATION
    Inventors: Ryoya Terakawa, Ryuichi Tanimoto, Hironori Kaneko
  • Publication number: 20180369985
    Abstract: A wafer polishing method of polishing one surface of a wafer by rotating a rotating platen to which a polishing pad is affixed and a pressurizing head while supplying slurry onto the rotating platen and pressurizing/holding the wafer on the polishing pad with the pressurizing head, the method including: calculating an F/T value by monitoring a load current value F of a motor for rotating the rotating platen and a surface temperature T of the polishing pad during the wafer polishing; and controlling at least one of the rotation speed of the rotating platen and the polishing pressure of the pressurizing head based on the calculated F/T value.
    Type: Application
    Filed: November 4, 2016
    Publication date: December 27, 2018
    Applicant: SUMCO CORPORATION
    Inventors: Tomonori KAWASAKI, Ryoya TERAKAWA
  • Publication number: 20180311783
    Abstract: A wafer polishing apparatus is provided with a rotating platen to which a polishing pad is affixed and a polishing head that holds a wafer placed on the polishing pad while pressing the wafer. The polishing head has a membrane that contacts the upper surface of the wafer and applying a pressing force thereto and a support plate that supports the membrane. The membrane has a main surface part facing the bottom surface of the support plate and a side surface part facing the outer peripheral edge surface of the support plate. The vertical tension due to the side surface part of the membrane is larger than the lateral tension due to the main surface part of the membrane.
    Type: Application
    Filed: October 12, 2016
    Publication date: November 1, 2018
    Applicant: SUMCO CORPORATION
    Inventors: Ryoya TERAKAWA, Ryuichi TANIMOTO, Hironori KANEKO
  • Patent number: 8784159
    Abstract: In a method for polishing a semiconductor wafer by rotating a work carrier and a table while pressing the semiconductor wafer retained by the work carrier against a polishing cloth mounted on the table, at a time when the table and the work carrier both having been at rest are rotated, each at a predetermined number of revolutions, in a condition that the polishing cloth and the semiconductor wafer are pressed against each other, to thereby start polishing, a table acceleration is maintained smaller than a work carrier acceleration. By such maintaining the table acceleration smaller than the work carrier acceleration, vibrations to be generated when the polishing is started can be prevented. In the method for polishing a semiconductor wafer according to the present invention, the diameter of the semiconductor wafer is preferably defined to be 30% or more of the diameter of the table.
    Type: Grant
    Filed: September 28, 2010
    Date of Patent: July 22, 2014
    Assignee: Sumco Corporation
    Inventors: Ryoya Terakawa, Kenji Aoki
  • Publication number: 20120208439
    Abstract: In a method for polishing a semiconductor wafer by rotating a work carrier and a table while pressing the semiconductor wafer retained by the work carrier against a polishing cloth mounted on the table, at a time when the table and the work carrier both having been at rest are rotated, each at a predetermined number of revolutions, in a condition that the polishing cloth and the semiconductor wafer are pressed against each other, to thereby start polishing, a table acceleration is maintained smaller than a work carrier acceleration. By such maintaining the table acceleration smaller than the work carrier acceleration, vibrations to be generated when the polishing is started can be prevented. In the method for polishing a semiconductor wafer according to the present invention, the diameter of the semiconductor wafer is preferably defined to be 30% or more of the diameter of the table.
    Type: Application
    Filed: September 28, 2010
    Publication date: August 16, 2012
    Applicant: SUMCO CORPORATION
    Inventors: Ryoya Terakawa, Kenji Aoki