Patents by Inventor Katsuyoshi Kojima

Katsuyoshi Kojima 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: 20240076521
    Abstract: A polishing liquid for polishing a compound semiconductor substrate includes an aqueous solution in which a permanganate is dissolved, and abrasive grains which are dispersed in the aqueous solution and an electrokinetic potential (zeta potential) of which is plus. Preferably, the polishing liquid has a pH of 3 to 7. In addition, preferably, a concentration of the permanganate is not less than 2.5 wt %, and a concentration of the abrasive grains is not less than 4.5 wt %. Besides, preferably, the abrasive grains include silica grains having an average primary grain diameter of 12 nm to 60 nm.
    Type: Application
    Filed: September 5, 2023
    Publication date: March 7, 2024
    Inventors: Ayumu SAKAI, Katsuyoshi KOJIMA
  • Publication number: 20240076522
    Abstract: A polishing liquid for polishing a compound semiconductor substrate includes an aqueous solution in which a permanganate and a water-soluble compound of a weak acid and a Group III element, a lanthanoid, or a Group IV element are dissolved. Preferably, the pH of the polishing liquid is 3 to 7. In addition, preferably, the concentration of the permanganate is not less than 2.50 wt %, and the concentration of the water-soluble compound is 0.55 wt % to 5.50 wt %.
    Type: Application
    Filed: September 5, 2023
    Publication date: March 7, 2024
    Inventors: Ayumu SAKAI, Katsuyoshi KOJIMA
  • Publication number: 20230142939
    Abstract: A method of manufacturing a SiC substrate includes grinding a sliced SiC substrate on a side of its front surface on which a Si-face is exposed, grinding the sliced SiC substrate on a side of its back surface on which a C-face is exposed, such that the back surface has an arithmetic mean height Sa of 1 nm or less, and then polishing the sliced SiC substrate on the side of only the front surface and not on the side of the back surface. In a case where the side of the back surface is ground as described above, the SiC substrate can be prevented from being warped even if the side of the back surface is not polished. This can shorten the manufacturing lead time for the SiC substrate used for the manufacture of power devices or the like and can also reduce the manufacturing cost.
    Type: Application
    Filed: November 10, 2022
    Publication date: May 11, 2023
    Inventor: Katsuyoshi KOJIMA
  • Patent number: 11612979
    Abstract: A polishing pad has a disk-shaped substrate and a polishing layer of which an upper surface side is adhered to the substrate. The polishing layer includes a plurality of through-holes which penetrate the polishing pad vertically and which are supplied with a polishing liquid, and a plurality of grooves which are formed on the lower surface side of the polishing pad and which are connected to the through-holes. The plurality of through-holes are formed such as to surround the center of the polishing layer, and the plurality of grooves are formed radially from the plurality of through-holes toward the outer periphery of the polishing layer.
    Type: Grant
    Filed: August 15, 2019
    Date of Patent: March 28, 2023
    Assignee: DISCO CORPORATION
    Inventors: Katsuyoshi Kojima, Arisa Kuroda
  • Publication number: 20200061773
    Abstract: A polishing pad has a disk-shaped substrate and a polishing layer of which an upper surface side is adhered to the substrate. The polishing layer includes a plurality of through-holes which penetrate the polishing pad vertically and which are supplied with a polishing liquid, and a plurality of grooves which are formed on the lower surface side of the polishing pad and which are connected to the through-holes. The plurality of through-holes are formed such as to surround the center of the polishing layer, and the plurality of grooves are formed radially from the plurality of through-holes toward the outer periphery of the polishing layer.
    Type: Application
    Filed: August 15, 2019
    Publication date: February 27, 2020
    Inventors: Katsuyoshi KOJIMA, Arisa KURODA
  • Publication number: 20190311910
    Abstract: A method of polishing an SiC substrate in contact with a polishing pad containing abrasive grains includes the steps of polishing the SiC substrate while supplying an acid polishing liquid to an area where the SiC substrate and the polishing pad contact each other, and thereafter, polishing the SiC substrate while supplying only water to the area while stopping supplying the acid polishing liquid.
    Type: Application
    Filed: April 2, 2019
    Publication date: October 10, 2019
    Inventors: Katsuyoshi KOJIMA, Norihisa ARIFUKU, Takeshi SATO
  • Patent number: 9994739
    Abstract: Provided is a polishing liquid which contains a permanganate, a pH adjustor, and water and which is used for polishing of a SiC substrate. Also provided is a method of polishing a SiC substrate, the method including: a first polishing step of polishing the SiC substrate by use of a first polishing liquid containing a permanganate, inorganic salts having an oxidizing ability, and water; and a second polishing step of performing finishing polishing of the SiC substrate by use of a second polishing liquid containing a permanganate, a pH adjustor, and water after the first polishing step.
    Type: Grant
    Filed: October 30, 2015
    Date of Patent: June 12, 2018
    Assignee: DISCO CORPORATION
    Inventors: Katsuyoshi Kojima, Takeshi Sato
  • Patent number: 9761454
    Abstract: A method of polishing a SiC substrate by supplying a polishing liquid and bringing a polishing pad into contact with the SiC substrate is provided. The polishing liquid contains a permanganate, inorganic salts having an oxidizing ability, and water. The method includes: a first polishing step of polishing the SiC substrate by use of a first polishing pad; and a second polishing step of polishing the SiC substrate by use of a second polishing pad softer than the first polishing pad after the first polishing step.
    Type: Grant
    Filed: October 28, 2015
    Date of Patent: September 12, 2017
    Assignee: DISCO CORPORATION
    Inventors: Katsuyoshi Kojima, Takeshi Sato
  • Publication number: 20160130475
    Abstract: Provided is a polishing liquid which contains a permanganate, a pH adjustor, and water and which is used for polishing of a SiC substrate. Also provided is a method of polishing a SiC substrate, the method including: a first polishing step of polishing the SiC substrate by use of a first polishing liquid containing a permanganate, inorganic salts having an oxidizing ability, and water; and a second polishing step of performing finishing polishing of the SiC substrate by use of a second polishing liquid containing a permanganate, a pH adjustor, and water after the first polishing step.
    Type: Application
    Filed: October 30, 2015
    Publication date: May 12, 2016
    Inventors: Katsuyoshi Kojima, Takeshi Sato
  • Publication number: 20160133466
    Abstract: A method of polishing a SiC substrate by supplying a polishing liquid and bringing a polishing pad into contact with the SiC substrate is provided. The polishing liquid contains a permanganate, inorganic salts having an oxidizing ability, and water. The method includes: a first polishing step of polishing the SiC substrate by use of a first polishing pad; and a second polishing step of polishing the SiC substrate by use of a second polishing pad softer than the first polishing pad after the first polishing step.
    Type: Application
    Filed: October 28, 2015
    Publication date: May 12, 2016
    Inventors: Katsuyoshi Kojima, Takeshi Sato
  • Patent number: 6976908
    Abstract: A polishing head includes a head body, a first recessed portion formed in the lower surface of the head body, a support plate which can be moved up and down in the first recessed portion, a first film-like member in which a first space is formed between the upper surface of the support plate and the head body, a second recessed portion formed in a lower surface of the support plate, a second film-like member, in which a second space is formed between the second film-like member and the support plate, and which holds a wafer on the lower, a communicating hole which is formed in the support plate to communicate the first space with the second space, and a gas supply device which increases pressures in the first and second spaces with a fluid to equal pressures to bring the object into press contact with the polishing pad.
    Type: Grant
    Filed: December 2, 2004
    Date of Patent: December 20, 2005
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Ceramics Co., LTD
    Inventors: Takayuki Masunaga, Shinobu Oofuchi, Hiromichi Isogai, Katsuyoshi Kojima
  • Publication number: 20050124269
    Abstract: A polishing head includes a head body, a first recessed portion formed in the lower surface of the head body, a support plate which can be moved up and down in the first recessed portion, a first film-like member in which a first space is formed between the upper surface of the support plate and the head body, a second recessed portion formed in a lower surface of the support plate, a second film-like member, in which a second space is formed between the second film-like member and the support plate, and which holds a wafer on the lower, a communicating hole which is formed in the support plate to communicate the first space with the second space, and a gas supply device which increases pressures in the first and second spaces with a fluid to equal pressures to bring the object into press contact with the polishing pad.
    Type: Application
    Filed: December 2, 2004
    Publication date: June 9, 2005
    Inventors: Takayuki Masunaga, Shinobu Oofuchi, Hiromichi Isogai, Katsuyoshi Kojima
  • Patent number: 6668662
    Abstract: The invention provides a viscoelasticity measuring device which is capable of imparting a desired displacement profile to a sample under conditions close to that of actual use. The viscoelasticity measuring device is composed of a presser to impart displacements to a sample; a rod to convey the displacements to the presser; a control jig kept in contact with an upper end portion of the rod and adapted to move to impart a desired displacement to the rod; a load cell which detects a load exerted to the sample to detect a stress generated in the sample; and a displacement sensor to detect the displacement in the sample; the displacements imparted of the sample being defined in accordance with a configuration and a moving speed of the control jig.
    Type: Grant
    Filed: January 28, 2002
    Date of Patent: December 30, 2003
    Assignee: Toshiba Ceramics Co., Ltd.
    Inventors: Hiromichi Isogai, Katsuyoshi Kojima, Takayuki Masunaga
  • Patent number: 6517422
    Abstract: A polishing apparatus which attaches the semi-conductor wafers 5 to the polishing plate 4 for performing the polishing as applying pressure the polishing cloth with the semi-conductor wafers, is provided with a guide ring 7 disposed outside of the polishing plate for pressing the polishing cloth separately from the polishing plate, a retainer ring 8 provided at the lower end of the guide ring for contacting the polishing cloth, and a weight 9 detachably mounted on the upper surface of the guide ring for adjusting the pressure to the polishing cloth.
    Type: Grant
    Filed: March 6, 2001
    Date of Patent: February 11, 2003
    Assignee: Toshiba Ceramics Co., Ltd.
    Inventors: Takao Sakamoto, Shinya Kawamoto, Katsuaki Kotari, Katsuyoshi Kojima, Masayoshi Saitou, Yoshihiko Hoshi
  • Publication number: 20020178795
    Abstract: The invention provides a viscoelasticity measuring device which is capable of imparting a desired displacement profile to a sample under conditions close to that of actual use. The viscoelasticity measuring device is composed of a presser to impart displacements to a sample; a rod to convey said displacements to said presser; a control jig kept in contact with an upper end portion of said rod and adapted to move to impart a desired displacement to said rod; a load cell which detects a load exerted to the sample to detect a stress generated in the sample; and a displacement sensor to detect the displacement in said sample; said displacements imparted of the sample being defined in accordance with a configuration and a moving speed of said control jig.
    Type: Application
    Filed: January 28, 2002
    Publication date: December 5, 2002
    Applicant: TOSHIBA CERAMICS CO., LTD.
    Inventors: Hiromichi Isogai, Katsuyoshi Kojima, Takayuki Masunaga
  • Publication number: 20010027081
    Abstract: A polishing apparatus which attaches the semi-conductor wafers 5 to the polishing plate 4 for performing the polishing as applying pressure the polishing cloth with the semi-conductor wafers, is provided with a guide ring 7 disposed outside of the polishing plate for pressing the polishing cloth separately from the polishing plate, a retainer ring 8 provided at the lower end of the guide ring for contacting the polishing cloth, and a weight 9 detachably mounted on the upper surface of the guide ring for adjusting the pressure to the polishing cloth.
    Type: Application
    Filed: March 6, 2001
    Publication date: October 4, 2001
    Inventors: Takao Sakamoto, Shinya Kawamoto, Katsuaki Kotari, Katsuyoshi Kojima, Masayoshi Saitou, Yoshihiko Hoshi