Patents by Inventor Eriko Kitahara

Eriko 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).

  • Patent number: 11939695
    Abstract: A quartz glass crucible 1 having a cylindrical side wall portion 10a, a bottom portion 10b, and a corner portion 10c includes a transparent layer 11 as an innermost layer made of quartz glass, a semi-molten layer 13 as an outermost layer made of raw material silica powder solidified in a semi-molten state, and a bubble layer 12 made of quartz glass interposed therebetween. An infrared transmissivity of the corner portion 10c in a state where the semi-molten layer 13 is removed is 25 to 51%, the infrared transmissivity of the corner portion 10c in the state where the semi-molten layer 13 is removed is lower than an infrared transmissivity of the side wall portion 10a, and the infrared transmissivity of the side wall portion 10a in the state where the semi-molten layer 13 is removed is lower than an infrared transmissivity of the bottom portion 10b.
    Type: Grant
    Filed: December 16, 2019
    Date of Patent: March 26, 2024
    Assignee: SUMCO CORPORATION
    Inventors: Ken Kitahara, Masanori Fukui, Hiroshi Kishi, Tomokazu Katano, Eriko Kitahara
  • Publication number: 20240011183
    Abstract: A quartz glass crucible has, from an inner surface side toward an outer surface side of the crucible, an inner transparent layer, a bubble layer, an outer transparent layer, and a crystallization accelerator-containing layer. An outer transition layer where a bubble content decreases from the bubble layer toward the outer transparent layer is provided at a boundary between the bubble layer and the outer transparent layer, and a thickness of the outer transition layer is 0.1 mm or more and 8 mm or less.
    Type: Application
    Filed: December 6, 2021
    Publication date: January 11, 2024
    Applicant: SUMCO Corporation
    Inventors: Eriko KITAHARA, Hiroshi KISHI, Hideki FUJIWARA
  • Patent number: 11703452
    Abstract: A measurement method and a measurement apparatus are capable of measuring the transmittance of a quartz crucible accurately. A measurement method includes: emitting a parallel light from a light source disposed on a side of one wall surface of a quartz crucible toward a predetermined measurement point of the quartz crucible; measuring reception levels of light transmitted through the quartz crucible at a plurality of positions by disposing a detector at the plurality of positions on a circle centered around an exit point of the parallel light on the other wall surface of the quartz crucible; and calculating a transmittance of the quartz crucible at the predetermined measurement point based on a plurality of the reception levels of the transmitted light measured at the plurality of positions.
    Type: Grant
    Filed: May 15, 2019
    Date of Patent: July 18, 2023
    Assignee: SUMCO CORPORATION
    Inventors: Yasunobu Shimizu, Keiichi Takanashi, Takeshi Fujita, Eriko Kitahara, Masanori Fukui
  • Publication number: 20230010489
    Abstract: A quartz glass crucible (1) has a structure wherein a peak of a distribution of a total concentration of Na, K, and Ca in a depth direction from an inner surface (10i) of the crucible is present at a position deeper than the inner surface (10i). In an exemplary embodiment, the quartz glass crucible is capable of improving the yield of a silicon single crystal by suppressing peeling-off of brown rings.
    Type: Application
    Filed: October 30, 2020
    Publication date: January 12, 2023
    Inventors: Masami OHARA, Hiroshi KISHI, Eriko KITAHARA
  • Patent number: 11473209
    Abstract: In an exemplary embodiment, a quartz glass crucible 1 includes: a cylindrical crucible body 10 which has a bottom and is made of quartz glass; and crystallization-accelerator-containing coating films 13A and 13B which are formed on surfaces of the crucible body 10 so as to cause crystallization-accelerator-enriched layers to be formed in the vicinity of the surfaces of the crucible body 10 by heating during a step of pulling up a silicon single crystal by a Czochralski method. The quartz glass crucible is capable of withstanding a single crystal pull-up step undertaken for a very long period of time, such as multi-pulling, and a manufacturing method thereof.
    Type: Grant
    Filed: April 2, 2018
    Date of Patent: October 18, 2022
    Assignee: SUMCO CORPORATION
    Inventors: Hiroshi Kishi, Kouta Hasebe, Takahiro Abe, Hideki Fujiwara, Eriko Kitahara
  • Publication number: 20220090290
    Abstract: A quartz glass crucible 1 having a cylindrical side wall portion 10a, a bottom portion 10b, and a corner portion 10c connecting the side wall portion 10a and the bottom portion 10b to each other includes a transparent layer 11 made of quartz glass, and a bubble layer 12 made of quartz glass and formed outside the transparent layer 11. A ratio of an infrared transmittance of the corner portion 10c at a maximum thickness position of the corner portion 10c to an infrared transmittance of the side wall portion 10a is 0.3 or more and 0.99 or less, and an absolute value of a rate of change in infrared transmittance in a height direction along a wall surface of the crucible from a center of the bottom portion 10b toward an upper end of the side wall portion 10a is 3%/cm or less.
    Type: Application
    Filed: December 16, 2019
    Publication date: March 24, 2022
    Inventors: Takeshi FUJITA, Ken KITAHARA, Tomokazu KATANO, Eriko KITAHARA
  • Publication number: 20220090291
    Abstract: A quartz glass crucible 1 having a cylindrical side wall portion 10a, a bottom portion 10b, and a corner portion 10c includes a transparent layer 11 as an innermost layer made of quartz glass, a semi-molten layer 13 as an outermost layer made of raw material silica powder solidified in a semi-molten state, and a bubble layer 12 made of quartz glass interposed therebetween. An infrared transmissivity of the corner portion 10c in a state where the semi-molten layer 13 is removed is 25 to 51%, the infrared transmissivity of the corner portion 10c in the state where the semi-molten layer 13 is removed is lower than an infrared transmissivity of the side wall portion 10a, and the infrared transmissivity of the side wall portion 10a in the state where the semi-molten layer 13 is removed is lower than an infrared transmissivity of the bottom portion 10b.
    Type: Application
    Filed: December 16, 2019
    Publication date: March 24, 2022
    Inventors: Ken KITAHARA, Masanori FUKUI, Hiroshi KISHI, Tomokazu KATANO, Eriko KITAHARA
  • Publication number: 20210181106
    Abstract: A measurement method and a measurement apparatus are capable of measuring the transmittance of a quartz crucible accurately. A measurement method includes: emitting a parallel light from a light source disposed on a side of one wall surface of a quartz crucible toward a predetermined measurement point of the quartz crucible; measuring reception levels of light transmitted through the quartz crucible at a plurality of positions by disposing a detector at the plurality of positions on a circle centered around an exit point of the parallel light on the other wall surface of the quartz crucible; and calculating a transmittance of the quartz crucible at the predetermined measurement point based on a plurality of the reception levels of the transmitted light measured at the plurality of positions.
    Type: Application
    Filed: May 15, 2019
    Publication date: June 17, 2021
    Applicant: SUMCO CORPORATION
    Inventors: Yasunobu SHIMIZU, Keiichi TAKANASHI, Takeshi FUJITA, Eriko KITAHARA, Masanori FUKUI
  • Publication number: 20200115820
    Abstract: Provided are a quartz glass crucible capable of withstanding a single crystal pull-up step undertaken for a very long period of time, such as multi-pulling, and a manufacturing method thereof. A quartz glass crucible 1 includes: a cylindrical crucible body 10 which has a bottom and is made of quartz glass; and crystallization-accelerator-containing coating films 13A and 13B which are formed on surfaces of the crucible body 10 so as to cause crystallization-accelerator-enriched layers to be formed in the vicinity of the surfaces of the crucible body 10 by heating during a step of pulling up a silicon single crystal by a Czochralski method.
    Type: Application
    Filed: April 2, 2018
    Publication date: April 16, 2020
    Inventors: Hiroshi KISHI, Kouta HASEBE, Takahiro ABE, Hideki FUJIWARA, Eriko KITAHARA
  • Patent number: 10266961
    Abstract: Buckling of a vitreous silica crucible or fall of a sidewall into the crucible is effectively suppressed. Furthermore, dislocations in a silicon single crystal are suppressed to enhance the yield of the single crystal. The vitreous silica crucible is used to pull single-crystal silicon and includes the cylindrical sidewall having an upward-opening rim, a mortar-shaped bottom including a curve, and a round portion connecting the sidewall and the bottom. The round portion is provided in such a manner that the curvature of the inner surface thereof is gradually increased from the sidewall toward the bottom in a section passing through the rotation axis of the vitreous silica crucible.
    Type: Grant
    Filed: October 31, 2012
    Date of Patent: April 23, 2019
    Assignee: SUMCO CORPORATION
    Inventors: Toshiaki Sudo, Tadahiro Sato, Eriko Kitahara, Takeshi Fujita
  • Patent number: 10024784
    Abstract: A vitreous silica crucible used to pull up silicon single crystal includes: a cylindrical straight body portion, a corner portion formed at a lower end of the straight body portion, and a bottom portion connected with the straight body portion via the corner portion, wherein the vitreous silica crucible further comprises: an opaque outer layer enclosing bubbles therein; and a transparent inner layer from which bubbles are removed, wherein the residual distortion's distribution obtained by measuring the silica glass's inner surface in a non-destructed state has an optical path difference which is 130 nm or less, which residual distortion's distribution is measured using a distortion-measuring apparatus which converts a linearly polarized light into circularly polarized light and then irradiates the crucible's wall.
    Type: Grant
    Filed: October 13, 2017
    Date of Patent: July 17, 2018
    Assignee: SUMCO CORPORATION
    Inventors: Toshiaki Sudo, Tadahiro Sato, Ken Kitahara, Eriko Kitahara
  • Patent number: 9964478
    Abstract: A destructive inspection method of a vitreous silica crucible for pulling a silicon single crystal evaluates a crack state of an inner surface of the vitreous silica crucible supported by a graphite susceptor when a load is instantaneously applied to at least one point on the inner surface via an automatic center punch while pushing the tip portion of the automatic center punch against the inner surface. The destructive inspection method can inspect the vitreous silica crucible under conditions as close to the actual conditions of use as possible.
    Type: Grant
    Filed: September 24, 2015
    Date of Patent: May 8, 2018
    Assignee: SUMCO CORPORATION
    Inventors: Ken Kitahara, Tadahiro Sato, Toshiaki Sudo, Eriko Kitahara, Takashi Watanabe
  • Patent number: 9932692
    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: Grant
    Filed: June 30, 2013
    Date of Patent: April 3, 2018
    Assignee: SUMCO CORPORATION
    Inventors: Toshiaki Sudo, Tadahiro Sato, Ken Kitahara, Eriko Kitahara
  • Publication number: 20180045639
    Abstract: A vitreous silica crucible used to pull up silicon single crystal includes: a cylindrical straight body portion, a corner portion formed at a lower end of the straight body portion, and a bottom portion connected with the straight body portion via the corner portion, wherein the vitreous silica crucible further comprises: an opaque outer layer enclosing bubbles therein; and a transparent inner layer from which bubbles are removed, wherein the residual distortion's distribution obtained by measuring the silica glass's inner surface in a non-destructed state has an optical path difference which is 130 nm or less, which residual distortion's distribution is measured using a distortion-measuring apparatus which converts a linearly polarized light into circularly polarized light and then irradiates the crucible's wall.
    Type: Application
    Filed: October 13, 2017
    Publication date: February 15, 2018
    Inventors: Toshiaki SUDO, Tadahiro SATO, Ken KITAHARA, Eriko KITAHARA
  • Patent number: 9863059
    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: Grant
    Filed: June 29, 2013
    Date of Patent: January 9, 2018
    Assignee: SUMCO CORPORATION
    Inventors: Toshiaki Sudo, Tadahiro Sato, Ken Kitahara, Eriko Kitahara
  • Patent number: 9863061
    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: Grant
    Filed: December 25, 2014
    Date of Patent: January 9, 2018
    Assignee: SUMCO CORPORATION
    Inventors: Toshiaki Sudo, Tadahiro Sato, Ken Kitahara, Eriko Kitahara
  • Patent number: 9816917
    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: Grant
    Filed: December 25, 2014
    Date of Patent: November 14, 2017
    Assignee: SUMCO CORPORATION
    Inventors: Toshiaki Sudo, Tadahiro Sato, Ken Kitahara, Eriko Kitahara
  • Patent number: 9809902
    Abstract: The present invention provides a method for evaluating a vitreous silica crucible which can measure a three-dimensional shape of the inner surface of the crucible in a non-destructive manner.
    Type: Grant
    Filed: October 31, 2012
    Date of Patent: November 7, 2017
    Assignee: SUMCO CORPORATION
    Inventors: Toshiaki Sudo, Tadahiro Sato, Ken Kitahara, Eriko Kitahara, Makiko Kodama
  • Publication number: 20170292901
    Abstract: A destructive inspection method of a vitreous silica crucible for pulling a silicon single crystal evaluates a crack state of an inner surface of the vitreous silica crucible supported by a graphite susceptor when a load is instantaneously applied to at least one point on the inner surface via an automatic center punch while pushing the tip portion of the automatic center punch against the inner surface. The destructive inspection method can inspect the vitreous silica crucible under conditions as close to the actual conditions of use as possible.
    Type: Application
    Filed: September 24, 2015
    Publication date: October 12, 2017
    Inventors: Ken KITAHARA, Tadahiro SATO, Toshiaki SUDO, Eriko KITAHARA, Takashi WATANABE
  • Publication number: 20170292204
    Abstract: Spatial coordinates of multiple points on an inner surface of a vitreous silica crucible are measured prior to filling raw material in the vitreous silica crucible, and a three-dimensional shape of the inner surface of the vitreous silica crucible using a combination of polygons having vertex coordinates constituted by the respective measured points is specified (S11); a predictive value of an initial liquid surface level of the silicon melt in the vitreous silica crucible is preset (S12); a volume of the silicon melt satisfying the predictive value of the initial liquid surface level is obtained based on the three-dimensional shape of the inner surface of the vitreous silica crucible (S13); a weight of the silicon melt having the volume is obtained (S14); raw material having the weight is filled in the vitreous silica crucible (S15); a dipping control of the seed crystal is performed based on the predictive value of the initial liquid surface level (S17).
    Type: Application
    Filed: September 24, 2015
    Publication date: October 12, 2017
    Inventors: Tadahiro SATO, Eriko KITAHARA, Toshiaki SUDO, Ken KITAHARA