Patents by Inventor Koji Izunome

Koji Izunome 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: 20220093396
    Abstract: A method for producing a three-dimensional structure, a method for producing a vertical transistor, a vertical transistor wafer, and a vertical transistor substrate, capable of suppressing the emission of Si due to a heat treatment and making an interface between an oxide film and a core mainly consisting of Si relatively smooth include: forming a three-dimensional shape by processing (for example, by etching) a surface layer of a monocrystalline silicon substrate, the surface layer having an oxygen concentration of 1×1017 atoms/cm3 or more; and then forming an oxide film on the surface of the three-dimensional shape by performing a heat treatment. The three-dimensional structure has a shape having projections and recesses in a thickness direction of the silicon substrate, and a height in the thickness direction of the silicon substrate is between 1 nm and 1000 nm, and preferably between 1 nm and 100 nm.
    Type: Application
    Filed: September 29, 2021
    Publication date: March 24, 2022
    Applicants: GLOBALWAFERS JAPAN CO., LTD., TOHOKU UNIVERSITY
    Inventors: Kazutaka KAMIJO, Etsuo FUKUDA, Takashi ISHIKAWA, Koji IZUNOME, Moriya MIYASHITA, Takao SAKAMOTO, Tetsuo ENDOH
  • Publication number: 20200211840
    Abstract: A method for producing a three-dimensional structure, a method for producing a vertical transistor, a vertical transistor wafer, and a vertical transistor substrate, capable of suppressing the emission of Si due to a heat treatment and making an interface between an oxide film and a core mainly consisting of Si relatively smooth include: forming a three-dimensional shape by processing (for example, by etching) a surface layer of a monocrystalline silicon substrate, the surface layer having an oxygen concentration of 1×1017 atoms/cm3 or more; and then forming an oxide film on the surface of the three-dimensional shape by performing a heat treatment. The three-dimensional structure has a shape having projections and recesses in a thickness direction of the silicon substrate, and a height in the thickness direction of the silicon substrate is between 1 nm and 1000 nm, and preferably between 1 nm and 100 nm.
    Type: Application
    Filed: July 17, 2018
    Publication date: July 2, 2020
    Applicants: GlobalWafers Japan Co., Ltd., TOHOKU UNIVERSITY
    Inventors: Kazutaka KAMIJO, Etsuo FUKUDA, Takashi ISHIKAWA, Koji IZUNOME, Moriya MIYASHITA, Takao SAKAMOTO, Tetsuo ENDOH
  • Patent number: 8999864
    Abstract: A silicon wafer for preventing a void defect in a bulk region from becoming source of contamination and slip generation in a device process is provided. And a heat-treating method thereof for reducing crystal defects such as COP in a region near the wafer surface to be a device active region is provided. The silicon wafer has a surface region 1 which is a defect-free region and a bulk region 2 including void defect of a polyhedron whose basic shape is an octahedron in which a corner portion of the polyhedron is in the curved shape and an inner-wall oxide film the void defect is removed. The silicon wafer is provided by performing a heat-treating method in which gas to be supplied, inner pressure of spaces and a maximum achievable temperature are set to a predetermined value when subjecting the silicon wafer produced by a CZ method to RTP.
    Type: Grant
    Filed: May 28, 2010
    Date of Patent: April 7, 2015
    Assignee: Global Wafers Japan Co., Ltd.
    Inventors: Takeshi Senda, Hiromichi Isogai, Eiji Toyoda, Koji Araki, Tatsuhiko Aoki, Haruo Sudo, Koji Izunome, Susumu Maeda, Kazuhiko Kashima, Hiroyuki Saito
  • Patent number: 8476149
    Abstract: A silicon wafer produced from a silicon single crystal ingot grown by Czochralski process is subjected to rapid heating/cooling thermal process at a maximum temperature (T1) of 1300° C. or more, but less than 1380° C. in an oxidizing gas atmosphere having an oxygen partial pressure of 20% or more, but less than 100%. The silicon wafer according to the invention has, in a defect-free region (DZ layer) including at least a device active region of the silicon wafer, a high oxygen concentration region having a concentration of oxygen solid solution of 0.7×1018 atoms/cm3 or more and at the same time, the defect-free region contains interstitial silicon in supersaturated state.
    Type: Grant
    Filed: July 30, 2009
    Date of Patent: July 2, 2013
    Assignee: Global Wafers Japan Co., Ltd.
    Inventors: Hiromichi Isogai, Takeshi Senda, Eiji Toyoda, Kumiko Murayama, Koji Izunome, Susumu Maeda, Kazuhiko Kashima, Koji Araki, Tatsuhiko Aoki, Haruo Sudo, Yoichiro Mochizuki, Akihiko Kobayashi, Senlin Fu
  • Patent number: 8399341
    Abstract: The invention is to provide a method for heat treating a silicon wafer reducing grown-in defects while suppressing generation of slip during RTP and improving surface roughness of the wafer. The method performing a first heat treatment while introducing a rare gas, the first heat treatment comprising the steps of rapidly heating the wafer to T1 of 1300° C. or higher and the melting point of silicon or lower, keeping the wafer at T1, rapidly cooling the wafer to T2 of 400-800° C. and keeping the wafer at T2; and performing a second heat treatment while introducing an oxygen gas in an amount of 20-100 vol. %, the second heat treatment comprising the steps of keeping the wafer at T2, rapidly heating the wafer from T2 to T3 of 1250° C. or higher and the melting point of silicon or lower, keeping the wafer at T3 and rapidly cooling the wafer.
    Type: Grant
    Filed: May 17, 2010
    Date of Patent: March 19, 2013
    Assignee: Covalent Materials Corporation
    Inventors: Takeshi Senda, Hiromichi Isogai, Eiji Toyoda, Kumiko Murayama, Koji Araki, Tatsuhiko Aoki, Haruo Sudo, Koji Izunome, Susumu Maeda, Kazuhiko Kashima
  • Patent number: 8252700
    Abstract: In a method of heat treating a wafer obtained by slicing a silicon single crystal ingot manufactured by the Czochralski method, a rapid heating/cooling heat treatment is carried out by setting a holding time at an ultimate temperature of 1200° C. or more and a melting point of silicon or less to be equal to or longer than one second and to be equal to or shorter than 60 seconds in a mixed gas atmosphere containing oxygen having an oxygen partial pressure of 1.0% or more and 20% or less and argon, and an oxide film having a thickness of 9.1 nm or less or 24.3 nm or more is thus formed on a surface of the silicon wafer.
    Type: Grant
    Filed: January 21, 2010
    Date of Patent: August 28, 2012
    Assignee: Covalent Materials Corporation
    Inventors: Takeshi Senda, Hiromichi Isogai, Eiji Toyoda, Kumiko Murayama, Koji Araki, Tatsuhiko Aoki, Haruo Sudo, Koji Izunome, Susumu Maeda, Kazuhiko Kashima
  • Publication number: 20120184091
    Abstract: The invention is to provide a method for heat treating a silicon wafer reducing grown-in defects while suppressing generation of slip during RTP and improving surface roughness of the wafer. The method performing a first heat treatment while introducing a rare gas, the first heat treatment comprising the steps of rapidly heating the wafer to T1 of 1300° C. or higher and the melting point of silicon or lower, keeping the wafer at T1, rapidly cooling the wafer to T2 of 400-800° C. and keeping the wafer at T2; and performing a second heat treatment while introducing an oxygen gas in an amount of 20-100 vol. %, the second heat treatment comprising the steps of keeping the wafer at T2, rapidly heating the wafer from T2 to T3 of 1250° C. or higher and the melting point of silicon or lower, keeping the wafer at T3 and rapidly cooling the wafer.
    Type: Application
    Filed: May 17, 2010
    Publication date: July 19, 2012
    Applicant: Covalent Materials Corporation
    Inventors: Takeshi Senda, Hiromichi Isogai, Eiji Toyoda, Kumiko Murayama, Koji Araki, Tatsuhiko Aoki, Haruo Sudo, Koji Izunome, Susumu Maeda, Kazuhiko Kashima
  • Publication number: 20120139088
    Abstract: A silicon wafer for preventing a void defect in a bulk region from becoming source of contamination and slip generation in a device process is provided. And a heat-treating method thereof for reducing crystal defects such as COP in a region near the wafer surface to be a device active region is provided. The silicon wafer has a surface region 1 which is a defect-free region and a bulk region 2 including void defect of a polyhedron whose basic shape is an octahedron in which a corner portion of the polyhedron is in the curved shape and an inner-wall oxide film the void defect is removed. The silicon wafer is provided by performing a heat-treating method in which gas to be supplied, inner pressure of spaces and a maximum achievable temperature are set to a predetermined value when subjecting the silicon wafer produced by a CZ method to RTP.
    Type: Application
    Filed: May 28, 2010
    Publication date: June 7, 2012
    Applicant: Covalent Materials Corporation
    Inventors: Takeshi Senda, Hiromichi Isogai, Eiji Toyoda, Koji Araki, Tatsuhiko Aoki, Haruo Sudo, Koji Izunome, Susumu Maeda, Kazuhiko Kashima, Hiroyuki Saito
  • Patent number: 7977219
    Abstract: In a manufacturing method for a silicon wafer, a first heat treatment process is performed on the silicon wafer while introducing a first gas having an oxygen gas in an amount of 0.01 vol. % or more and 1.00 vol. % or less and a rare gas, and a second heat treatment process is performed while stopping introducing the first gas and introducing a second gas having an oxygen gas in an amount of 20 vol. % or more and 100 vol. % or less and a rare gas. In the first heat treatment process, the silicon wafer is rapidly heated to first temperature of 1300° C. or higher and a melting point of silicon or lower at a first heating rate, and kept at the first temperature. In the second heat treatment process, the silicon wafer is kept at the first temperature, and rapidly cooled from the first temperature at a first cooling rate.
    Type: Grant
    Filed: July 30, 2009
    Date of Patent: July 12, 2011
    Assignee: Covalent Materials Corporation
    Inventors: Hiromichi Isogai, Takeshi Senda, Eiji Toyoda, Kumiko Murayama, Koji Izunome, Susumu Maeda, Kazuhiko Kashima
  • Publication number: 20100197146
    Abstract: In a method of heat treating a wafer obtained by slicing a silicon single crystal ingot manufactured by the Czochralski method, a rapid heating/cooling heat treatment is carried out by setting a holding time at an ultimate temperature of 1200° C. or more and a melting point of silicon or less to be equal to or longer than one second and to be equal to or shorter than 60 seconds in a mixed gas atmosphere containing oxygen having an oxygen partial pressure of 1.0% or more and 20% or less and argon, and an oxide film having a thickness of 9.1 nm or less or 24.3 nm or more is thus formed on a surface of the silicon wafer.
    Type: Application
    Filed: January 21, 2010
    Publication date: August 5, 2010
    Applicant: COVALENT MATERIALS CORPORATION
    Inventors: Takeshi Senda, Hiromichi Isogai, Eiji Toyoda, Kumiko Murayama, Koji Araki, Tatsuhiko Aoki, Haruo Sudo, Koji Izunome, Susumu Maeda, Kazuhiko Kashima
  • Patent number: 7679730
    Abstract: An image pickup device disposed in a predetermined position relative to a surface of a strained silicon wafer photographs the surface of the strained silicon wafer in a plurality of rotation angle positions on photographing conditions under which bright lines appearing on the surface of the strained silicon wafer can be photographed, in an environment where a light source device illuminates the surface of the strained silicon wafer which is rotating. A composite image in a predetermined angle position is generated from surface images of the strained silicon wafer in a plurality of rotation angle positions obtained by the image pickup device.
    Type: Grant
    Filed: September 13, 2007
    Date of Patent: March 16, 2010
    Assignees: Shibaura Mechatronics Corporation, Covalent Materials Corporation
    Inventors: Hideaki Takano, Miyuki Shimizu, Takeshi Senda, Koji Izunome, Yoshinori Hayashi, Kazuhiko Hamatani
  • Publication number: 20100055884
    Abstract: In a manufacturing method for a silicon wafer, a first heat treatment process is performed on the silicon wafer while introducing a first gas having an oxygen gas in an amount of 0.01 vol. % or more and 1.00 vol. % or less and a rare gas, and a second heat treatment process is performed while stopping introducing the first gas and introducing a second gas having an oxygen gas in an amount of 20 vol. % or more and 100 vol. % or less and a rare gas. In the first heat treatment process, the silicon wafer is rapidly heated to first temperature of 1300° C. or higher and a melting point of silicon or lower at a first heating rate, and kept at the first temperature. In the second heat treatment process, the silicon wafer is kept at the first temperature, and rapidly cooled from the first temperature at a first cooling rate.
    Type: Application
    Filed: July 30, 2009
    Publication date: March 4, 2010
    Inventors: Hiromichi Isogai, Takeshi Senda, Eiji Toyoda, Kumiko Murayama, Koji Izunome, Susumu Maeda, Kazuhiko Kashima
  • Publication number: 20100038757
    Abstract: A silicon wafer produced from a silicon single crystal ingot grown by Czochralski process is subjected to rapid heating/cooling thermal process at a maximum temperature (T1) of 1300° C. or more, but less than 1380° C. in an oxidizing gas atmosphere having an oxygen partial pressure of 20% or more, but less than 100%. The silicon wafer according to the invention has, in a defect-free region (DZ layer) including at least a device active region of the silicon wafer, a high oxygen concentration region having a concentration of oxygen solid solution of 0.7×1018 atoms/cm3 or more and at the same time, the defect-free region contains interstitial silicon in supersaturated state.
    Type: Application
    Filed: July 30, 2009
    Publication date: February 18, 2010
    Inventors: Hiromichi Isogai, Takeshi Senda, Eiji Toyoda, Kumiko Murayama, Koji Izunome, Susumu Maeda, Kazuhiko Kashima, Koji Araki, Tatsuhiko Aoki, Haruo Sudo, Yoichiro Mochizuki, Akihiko Kobayashi, Senlin Fu
  • Publication number: 20090066933
    Abstract: An image pickup device disposed in a predetermined position relative to a surface of a strained silicon wafer photographs the surface of the strained silicon wafer in a plurality of rotation angle positions on photographing conditions under which bright lines appearing on the surface of the strained silicon wafer can be photographed, in an environment where a light source device illuminates the surface of the strained silicon wafer which is rotating. A composite image in a predetermined angle position is generated from surface images of the strained silicon wafer in a plurality of rotation angle positions obtained by the image pickup device.
    Type: Application
    Filed: March 27, 2006
    Publication date: March 12, 2009
    Applicants: SHIBAURA MECHATRONICS CORPORATION, COVALENT MATERIALS CORPORATION
    Inventors: Hideaki Takano, Miyuki Shimizu, Takeshi Sendia, Koji Izunome, Yoshinori Hayashi, Kazuhiko Hamatani
  • Publication number: 20090004825
    Abstract: A method of manufacturing a semiconductor substrate having a DSB structure that enables simplification of a manufacturing process by optimizing a total thickness of oxides on surfaces of two wafers before being bonded together is provided. The method comprises a process of preparing a first semiconductor wafer and a second semiconductor wafer, a process of bonding the first semiconductor wafer and second semiconductor wafer when a total of thickness of an oxide on the surface of the first semiconductor wafer and that of an oxide on the surface of the second semiconductor wafer is 0.4 nm or more and 1.0 nm or less, and a process of providing heat treatment to a semiconductor substrate after the process of the bonding and before a process of thinning one of the wafers.
    Type: Application
    Filed: January 4, 2008
    Publication date: January 1, 2009
    Applicant: Covalent Materials Corporation
    Inventors: Takeshi SENDA, Hiromichi ISOGAI, Eiji TOYODA, Akiko NARITA, Koji IZUNOME
  • Patent number: 7403278
    Abstract: A surface inspection apparatus, for inspecting a plurality of surfaces formed in a peripheral edge portion of a plate-like object, includes a image pickup mechanism, which photographs the peripheral edge portion of the plate-like object having a plurality of surfaces, and an image processing device, which processes an image obtained by the photographing device. The image pickup mechanism includes an optical system which guides images of the plurality of surfaces of the plate-like object in one direction, and a camera unit having an image pickup surface, on which the images of the plurality of surfaces guided by the optical system in the one direction are formed.
    Type: Grant
    Filed: May 29, 2007
    Date of Patent: July 22, 2008
    Assignees: Shibaura Mechatronics Corporation, Covalent Materials Corporation
    Inventors: Yoshinori Hayashi, Hiroyuki Naraidate, Makoto Kyoya, Koji Izunome, Hiromi Nagahama, Miyuki Shimizu, Kazuhiko Hamatani
  • Publication number: 20080164572
    Abstract: A semiconductor substrate whose surface roughness is reduced by optimizing an inclination (off angle) with respect to a {110} surface of the semiconductor substrate surface and a manufacturing method thereof are provided. The surface of the semiconductor substrate has the inclination (off angle) of 0 degree or more and 0.12 degrees or less, or 5 degrees or more and 11 degrees or less, preferably 6 degrees or more and 9 degrees or less with respect to the {110} surface. The manufacturing method of a semiconductor substrate has a process in which a semiconductor single crystal ingot is sliced at an inclination (off angle) of 5 degrees or more and 11 degrees or less, preferably 6 degrees or more and 9 degrees or less with respect to the {110} surface.
    Type: Application
    Filed: December 19, 2007
    Publication date: July 10, 2008
    Applicant: Covalent Materials Corporation
    Inventors: Eiji Toyoda, Takeshi Senda, Akiko Narita, Hiromichi Isogai, Koji Izunome
  • Publication number: 20080166891
    Abstract: The present invention provides a heat treatment method for a silicon wafer in which, with respect to a surface of the silicon wafer made flat at an atomic level by a high-temperature heat-treatment at 1,100° C. or more, a surface roughness of the wafer can be reduced compared with the conventional one while maintaining a step terrace structure on the surface of the above-mentioned wafer, and the surface of such a wafer can be formed stably. In the heat treatment method for the silicon wafer in which the step terrace structure is formed on the surface of the silicon wafer, after the silicon wafer is heat treated at 1,100° C. or more in a heat treatment furnace in a reducing gas or inert gas atmosphere, the atmosphere in the furnace is arranged to be of argon gas at a temperature of 500° C.
    Type: Application
    Filed: December 27, 2007
    Publication date: July 10, 2008
    Inventors: Manabu Hirasawa, Koji Izunome, Koji Araki, Tatsuhiko Aoki
  • Publication number: 20070240628
    Abstract: Provided is a silicon wafer suitable for manufacturing a semiconductor device having a shallow junction. A silicon wafer wherein, in a region at a depth of less than 50 ?m from a surface, a density of oxygen deposition materials each having a diameter of not less than 10 nm is not more than 1×108/cm3. A silicon wafer for a semiconductor device, which is manufactured by applying heat treatment at a heat treatment temperature of not less than 1000° C. for heat treatment time of not more than 3 msec, wherein, in a region at a depth of less than 50 ?m from a surface, a density of oxygen deposition materials each having a diameter of not less than 10 nm is not more than 1×108/cm3.
    Type: Application
    Filed: April 5, 2007
    Publication date: October 18, 2007
    Applicant: Toshiba Ceramics Co., Ltd
    Inventors: Takashi Watanabe, Hiroyuki Saito, Takeshi Senda, Koji Izunome, Kazuhiko Kashima
  • Publication number: 20070222977
    Abstract: A surface inspection apparatus, for inspecting a plurality of surfaces formed in a peripheral edge portion of a plate-like object, includes a image pickup mechanism, which photographs the peripheral edge portion of the plate-like object having a plurality of surfaces, and an image processing device, which processes an image obtained by the photographing device. The image pickup mechanism includes an optical system which guides images of the plurality of surfaces of the plate-like object in one direction, and a camera unit having an image pickup surface, on which the images of the plurality of surfaces guided by the optical system in the one direction are formed.
    Type: Application
    Filed: May 29, 2007
    Publication date: September 27, 2007
    Applicants: SHIBAURA MECHATRONICS CORPORATION, TOSHIBA CERAMICS CO., LTD.
    Inventors: Yoshinori Hayashi, Hiroyuki Naraidate, Makoto Kyoya, Koji Izunome, Hiromi Nagahama, Miyuki Shimizu, Kazuhiko Hamatani