Patents by Inventor Ken Kitahara

Ken Kitahara 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: 20170218534
    Abstract: A quality-evaluated vitreous silica crucible for pulling silicon single crystal is provided, wherein an inner surface of the vitreous silica crucible has regions where surface defects including brown rings are to be generated when pulling silicon single crystal. The regions are distinguished using an infrared absorption spectrum or a Raman shift of the regions, wherein a position of each region and/or a density of the regions are/is specified.
    Type: Application
    Filed: April 14, 2017
    Publication date: August 3, 2017
    Inventors: Toshiaki SUDO, Tadahiro SATO, Ken KITAHARA, Masami OHARA
  • Patent number: 9708730
    Abstract: A quality-evaluated vitreous silica crucible for pulling silicon single crystal is provided, wherein an inner surface of the vitreous silica crucible has regions where surface defects including brown rings are to be generated when pulling silicon single crystal. The regions are distinguished using an infrared absorption spectrum or a Raman shift of the regions, wherein a position of each region and/or a density of the regions are/is specified.
    Type: Grant
    Filed: April 14, 2017
    Date of Patent: July 18, 2017
    Assignee: SUMCO CORPORATION
    Inventors: Toshiaki Sudo, Tadahiro Sato, Ken Kitahara, Masami Ohara
  • Patent number: 9653268
    Abstract: A method of manufacturing a vitreous silica crucible includes an inspection method comprising: a measurement step of measuring an infrared absorption spectrum or a Raman shift of a measurement point on an inner surface of the vitreous silica crucible; a determining step of predicting whether a surface defect region is generated or not in the measurement point based on an obtained spectrum to determine a quality of the vitreous silica crucible.
    Type: Grant
    Filed: December 13, 2016
    Date of Patent: May 16, 2017
    Assignee: SUMCO CORPORATION
    Inventors: Toshiaki Sudo, Tadahiro Sato, Ken Kitahara, Masami Ohara
  • Patent number: 9637405
    Abstract: An evaluation method of suitable silica powder for forming a bubble-free layer of a vitreous silica crucible for pulling of a silicon single crystal, includes: a process of measuring a porosity between silica particles in the silica powder, a process of melting the silica powder, a process of measuring a bubble content rate of a vitreous silica block obtained by cooling to harden the melted silica powder, and a process of determining whether the silica powder is suitable from the porosity of the silica powder and the bubble content rate of the vitreous silica block.
    Type: Grant
    Filed: June 30, 2013
    Date of Patent: May 2, 2017
    Assignee: SUMCO CORPORATION
    Inventors: Toshiaki Sudo, Tadahiro Sato, Ken Kitahara, Makiko Hinooka
  • Publication number: 20170088973
    Abstract: A method of manufacturing a vitreous silica crucible includes an inspection method comprising: a measurement step of measuring an infrared absorption spectrum or a Raman shift of a measurement point on an inner surface of the vitreous silica crucible; a determining step of predicting whether a surface defect region is generated or not in the measurement point based on an obtained spectrum to determine a quality of the vitreous silica crucible.
    Type: Application
    Filed: December 13, 2016
    Publication date: March 30, 2017
    Inventors: Toshiaki SUDO, Tadahiro SATO, Ken KITAHARA, Masami OHARA
  • Patent number: 9557276
    Abstract: An inspection method of vitreous silica crucibles includes: a measurement step of measuring an infrared absorption spectrum or a Raman shift of a measurement point on an inner surface of the vitreous silica crucible; a determining step of predicting whether or not a surface-defect region occurs at the measurement point based on an obtained spectrum to determine a quality of the vitreous silica crucible.
    Type: Grant
    Filed: June 30, 2013
    Date of Patent: January 31, 2017
    Assignee: SUMCO CORPORATION
    Inventors: Toshiaki Sudo, Tadahiro Sato, Ken Kitahara, Masami Ohara
  • Patent number: 9527763
    Abstract: A method of manufacturing a composite crucible includes: supplying mullite material powder to an upper region of a mold, and supplying second silica powder to a lower region provided below the upper region while rotating the mold; supplying third silica powder on an inner surface side of a layer made of the mullite material powder and the second silica powder; heating and fusing the mullite material powder, the second silica powder, and the third silica powder to form an opaque vitreous silica layer provided on the outer surface of the crucible, a transparent vitreous silica layer provided on an inner surface side of the crucible, and a mullite reinforcement layer provided on the outer surface side of an upper end portion of the crucible.
    Type: Grant
    Filed: December 27, 2015
    Date of Patent: December 27, 2016
    Assignee: SUMCO CORPORATION
    Inventors: Toshiaki Sudo, Ken Kitahara, Takuma Yoshioka
  • Publication number: 20160313234
    Abstract: In an embodiment, a distortion-measuring apparatus for measuring a distortion distribution of an entire vitreous silica crucible in a non-destructive way includes: a light source 11; a first polarizer 12 and a first quarter-wave plate 13 disposed between the light source 11 and an outer surface of a vitreous silica crucible wall; a camera 14 disposed inside of a vitreous silica crucible 1; a camera control mechanism 15 configured to control a photographing direction of the camera 14; a second polarizer 16 and a second quarter-wave plate 17 disposed between the camera 14 and an inner surface of the vitreous silica crucible wall. An optical axis of the second quarter-wave plate 17 inclines 90 degrees with respect to the first quarter-wave plate 13.
    Type: Application
    Filed: December 25, 2014
    Publication date: October 27, 2016
    Applicant: SUMCO CORPORATION
    Inventors: Toshiaki SUDO, Tadahiro SATO, Ken KITAHARA, Eriko KITAHARA
  • Publication number: 20160289862
    Abstract: In an embodiment, a vitreous silica crucible 1 includes a cylindrical straight body portion 10a, a corner portion 10c formed at lower end of the straight body portion 10a, and a bottom portion 10b connected with the straight body portion 10a via the corner portion 10c. Moreover, the vitreous silica crucible 1 includes a bubble-containing opaque layer 11 constituting an outer layer, and a bubble-free transparent layer 12 constituting an inner layer. A boundary surface, between the opaque layer 11 and the transparent layer 12 in at least the straight body portion 10a, forms a periodic wave surface in a vertical direction. The vitreous silica crucible can suppress deformation under high temperature.
    Type: Application
    Filed: December 25, 2014
    Publication date: October 6, 2016
    Applicant: SUMCO CORPORATION
    Inventors: Toshiaki SUDO, Tadahiro SATO, Ken KITAHARA, Eriko KITAHARA
  • Publication number: 20160201216
    Abstract: A vitreous silica crucible includes: a substantially cylindrical straight body portion having an opening on a top end and extending in a vertical direction; a curved bottom portion; and a corner portion connecting the straight body portion with the bottom portion and a curvature of which is greater than that of the bottom portion, wherein an inner surface of the crucible has a concavo-convex structure in which groove-shaped valleys are interposed between ridges, and an average interval of the ridges is 5-100 ?m.
    Type: Application
    Filed: June 30, 2013
    Publication date: July 14, 2016
    Inventors: Toshiaki SUDO, Tadahiro SATO, Ken KITAHARA, Eriko KITAHARA
  • Publication number: 20160200617
    Abstract: An evaluation method of suitable silica powder for forming a bubble-free layer of a vitreous silica crucible for pulling of a silicon single crystal, includes: a process of measuring a porosity between silica particles in the silica powder, a process of melting the silica powder, a process of measuring a bubble content rate of a vitreous silica block obtained by cooling to harden the melted silica powder, and a process of determining whether the silica powder is suitable from the porosity of the silica powder and the bubble content rate of the vitreous silica block.
    Type: Application
    Filed: June 30, 2013
    Publication date: July 14, 2016
    Inventors: Toshiaki SUDO, Tadahiro SATO, Ken KITAHARA, Makiko HINOOKA
  • Publication number: 20160202192
    Abstract: An inspection method of vitreous silica crucibles includes: a measurement step of measuring an infrared absorption spectrum or a Raman shift of a measurement point on an inner surface of the vitreous silica crucible; a determining step of predicting whether or not a surface-defect region occurs at the measurement point based on an obtained spectrum to determine a quality of the vitreous silica crucible.
    Type: Application
    Filed: June 30, 2013
    Publication date: July 14, 2016
    Inventors: Toshiaki SUDO, Tadahiro SATO, Ken KITAHARA, Masami OHARA
  • Publication number: 20160153116
    Abstract: A method for pulling silicon single crystal includes a process of placing a molded body between a susceptor's inner surface and a crucible's outer surface. The molded body is formed based on three-dimensional data of the inner surface shape of the susceptor which can hold the vitreous silica crucible and three-dimensional data of the crucible so as to make the susceptor's central axis and the crucible's central axis substantially aligned when it is placed between the susceptor's inner surface and the crucible's outer surface.
    Type: Application
    Filed: June 29, 2013
    Publication date: June 2, 2016
    Inventors: Toshiaki SUDO, Tadahiro SATO, Ken KITAHARA, Eriko KITAHARA
  • Patent number: 9347148
    Abstract: Provided is a vitreous silica crucible, which is resistant to deformation and corrosion even when heated at high temperature for a long time. There is provided a vitreous silica crucible of the present invention including a substantially cylindrical straight body portion, a curved bottom portion, and a corner portion smoothly connecting the straight body portion and the bottom portion, wherein a wall of the vitreous silica crucible includes, from an inner surface side, a transparent layer and a bubble-containing layer, and a ratio of a thickness of the bubble-containing layer with respect to a thickness of the transparent layer at an intermediate position between an upper end and a lower end of the straight body portion is 0.7 to 1.4.
    Type: Grant
    Filed: November 30, 2011
    Date of Patent: May 24, 2016
    Assignee: SUMCO CORPORATION
    Inventors: Toshiaki Sudo, Ken Kitahara, Koichi Suzuki, Shinsuke Yamazaki
  • Publication number: 20160115625
    Abstract: A method of manufacturing a composite crucible includes: supplying mullite material powder to an upper region of a mold, and supplying second silica powder to a lower region provided below the upper region while rotating the mold; supplying third silica powder on an inner surface side of a layer made of the mullite material powder and the second silica powder; heating and fusing the mullite material powder, the second silica powder, and the third silica powder to form an opaque vitreous silica layer provided on the outer surface of the crucible, a transparent vitreous silica layer provided on an inner surface side of the crucible, and a mullite reinforcement layer provided on the outer surface side of an upper end portion of the crucible.
    Type: Application
    Filed: December 27, 2015
    Publication date: April 28, 2016
    Inventors: Toshiaki SUDO, Ken KITAHARA, Takuma YOSHIOKA
  • Publication number: 20160108550
    Abstract: The present invention provides a vitreous silica crucible which inhibits a deformation even when used under a high temperature condition for a long time, and a method for manufacturing the same. The vitreous silica crucible comprises: a substantially cylindrical straight body portion having an opening on the top end and extending in a vertical direction, a curved bottom portion, and a corner portion connecting the straight body portion with the bottom portion and a curvature of which is greater than that of the bottom portion, wherein, the vitreous silica crucible comprises a transparent layer on the inside and a bubble layer on the outside thereof, a compressive stress layer in which compressive stress remains in the inner surface side of the transparent layer, and a tensile stress layer in which tensile stress remains and is adjacent to the compressive stress layer at a gradual rate of change of stress.
    Type: Application
    Filed: May 31, 2013
    Publication date: April 21, 2016
    Inventors: Toshiaki SUDO, Ken KITAHARA, Akihiro AIBA, Kazushi OUSYUYA, Fumie YOSHIDA, Makiko HINOOKA, Eriko KITAHARA, Tadahiro SATO
  • Patent number: 9266763
    Abstract: The purpose of the present invention is to provide a crucible which has high viscosity at high temperature, can be used for a long time, and can be manufactured at low cost, and a method of manufacturing the crucible. The present invention provides a composite crucible including a vitreous silica crucible body having a sidewall portion and a bottom portion, and a reinforcement layer provided on an outer surface side of an upper end portion of the vitreous silica crucible body, wherein the reinforcement layer is made of mullite material whose main component is alumina and silica.
    Type: Grant
    Filed: December 22, 2011
    Date of Patent: February 23, 2016
    Assignee: SUMCO CORPORATION
    Inventors: Toshiaki Sudo, Ken Kitahara, Takuma Yoshioka
  • Publication number: 20150349492
    Abstract: To provide a tunable external resonator laser with mode-hop-free for broadband. For solving the problem, in a tunable external laser comprising, the offset is given between the pivot and the diffraction grating. The tunable external resonator laser comprising, a laser chip which emits light; a lens which collimates the light emitted from said laser chip, a diffraction grating which diffracts the light collimated by said lens, a support body which said diffraction grating is fixed, and a movable mirror which reflects the light diffracted by said diffraction grating, wherein said diffraction grating is arranged apart a prescribed distance from a Littman-type tunable external resonator laser arrangement in which said movable mirror rotates on a pivot which is the intersection point of the surface of said movable mirror and the surface of the said diffraction grating.
    Type: Application
    Filed: September 19, 2013
    Publication date: December 3, 2015
    Inventors: Kiyofumi MURO, Yuji WAKABAYASHI, Tomohisa ENDO, Ken KITAHARA
  • Publication number: 20150337456
    Abstract: A composite crucible 10 is characterized in the use of mullite (3Al2O3.2SiO2) as the basic material of the crucible. The composite crucible 10 has a crucible body 11 made of mullite material whose main component is alumina and silica, and a transparent vitreous silica layer 12 formed on the inner surface of the crucible body 11. The thickness of the transparent vitreous silica layer 12 is smaller than that of the crucible body 11. The crucible body 11 is formed by the slip casting method, and the transparent vitreous silica layer 12 is formed by the thermal spraying method.
    Type: Application
    Filed: August 4, 2015
    Publication date: November 26, 2015
    Inventors: Toshiaki SUDO, Takuma YOSHIOKA, Hiroshi KISHI, Takeshi FUJITA, Minoru KANDA, Koichi SUZUKI, Ken KITAHARA
  • Patent number: 9133063
    Abstract: The purpose of the present invention is to provide a crucible which has high viscosity at high temperature, and can be used for a long time, and can be manufactured at low cost, and a method of manufacturing the same. The composite crucible 10 is characterized in the use of mullite (3Al2O3.2SiO2) as the basic material of the crucible. The composite crucible 10 has the crucible body 11 made of mullite material whose main component is alumina and silica, and a transparent vitreous silica layer 12 formed on the inner surface of the crucible body 11. The thickness of the transparent vitreous silica layer 12 is smaller than that of the crucible body 11. The crucible body 11 can be formed by the slip casting method, and the transparent vitreous silica layer 12 can be formed by the thermal spraying method.
    Type: Grant
    Filed: August 20, 2010
    Date of Patent: September 15, 2015
    Assignee: SUMCO CORPORATION
    Inventors: Toshiaki Sudo, Takuma Yoshioka, Hiroshi Kishi, Takeshi Fujita, Minoru Kanda, Koichi Suzuki, Ken Kitahara