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).
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Publication number: 20230142939Abstract: 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: ApplicationFiled: November 10, 2022Publication date: May 11, 2023Inventor: Katsuyoshi KOJIMA
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Patent number: 11612979Abstract: 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: GrantFiled: August 15, 2019Date of Patent: March 28, 2023Assignee: DISCO CORPORATIONInventors: Katsuyoshi Kojima, Arisa Kuroda
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Publication number: 20200061773Abstract: 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: ApplicationFiled: August 15, 2019Publication date: February 27, 2020Inventors: Katsuyoshi KOJIMA, Arisa KURODA
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Publication number: 20190311910Abstract: 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: ApplicationFiled: April 2, 2019Publication date: October 10, 2019Inventors: Katsuyoshi KOJIMA, Norihisa ARIFUKU, Takeshi SATO
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Patent number: 9994739Abstract: 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: GrantFiled: October 30, 2015Date of Patent: June 12, 2018Assignee: DISCO CORPORATIONInventors: Katsuyoshi Kojima, Takeshi Sato
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Patent number: 9761454Abstract: 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: GrantFiled: October 28, 2015Date of Patent: September 12, 2017Assignee: DISCO CORPORATIONInventors: Katsuyoshi Kojima, Takeshi Sato
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Publication number: 20160133466Abstract: 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: ApplicationFiled: October 28, 2015Publication date: May 12, 2016Inventors: Katsuyoshi Kojima, Takeshi Sato
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Publication number: 20160130475Abstract: 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: ApplicationFiled: October 30, 2015Publication date: May 12, 2016Inventors: Katsuyoshi Kojima, Takeshi Sato
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Patent number: 6976908Abstract: 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: GrantFiled: December 2, 2004Date of Patent: December 20, 2005Assignees: Kabushiki Kaisha Toshiba, Toshiba Ceramics Co., LTDInventors: Takayuki Masunaga, Shinobu Oofuchi, Hiromichi Isogai, Katsuyoshi Kojima
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Publication number: 20050124269Abstract: 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: ApplicationFiled: December 2, 2004Publication date: June 9, 2005Inventors: Takayuki Masunaga, Shinobu Oofuchi, Hiromichi Isogai, Katsuyoshi Kojima
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Patent number: 6668662Abstract: 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: GrantFiled: January 28, 2002Date of Patent: December 30, 2003Assignee: Toshiba Ceramics Co., Ltd.Inventors: Hiromichi Isogai, Katsuyoshi Kojima, Takayuki Masunaga
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Patent number: 6517422Abstract: 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: GrantFiled: March 6, 2001Date of Patent: February 11, 2003Assignee: Toshiba Ceramics Co., Ltd.Inventors: Takao Sakamoto, Shinya Kawamoto, Katsuaki Kotari, Katsuyoshi Kojima, Masayoshi Saitou, Yoshihiko Hoshi
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Publication number: 20020178795Abstract: 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: ApplicationFiled: January 28, 2002Publication date: December 5, 2002Applicant: TOSHIBA CERAMICS CO., LTD.Inventors: Hiromichi Isogai, Katsuyoshi Kojima, Takayuki Masunaga
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Publication number: 20010027081Abstract: 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: ApplicationFiled: March 6, 2001Publication date: October 4, 2001Inventors: Takao Sakamoto, Shinya Kawamoto, Katsuaki Kotari, Katsuyoshi Kojima, Masayoshi Saitou, Yoshihiko Hoshi