Patents Assigned to Sumco Corporation
  • 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
  • Patent number: 11466381
    Abstract: A quartz glass crucible 1 includes: a quartz glass crucible body 10 having a cylindrical side wall portion 10a, a curved bottom portion 10b, and a corner portion 10c which has a larger curvature than that of the bottom portion 10b and connects the side wall portion 10a and the bottom portion 10b to each other; and an inner-surface coating film 13A which contains a crystallization accelerator and is formed on an inner surface 10i of the quartz glass crucible body 10, in which the inner surface 10i of the quartz glass crucible body 10 is under compressive stress. The quartz glass crucible has high durability even at a high temperature during a single crystal pull-up step and is capable of reducing a generation ratio of pinholes in a silicon single crystal.
    Type: Grant
    Filed: February 13, 2019
    Date of Patent: October 11, 2022
    Assignee: SUMCO CORPORATION
    Inventors: Hiroshi Kishi, Kouta Hasebe, Takahiro Abe, Hideki Fujiwara
  • Publication number: 20220319851
    Abstract: A manufacturing method of an epitaxial silicon wafer includes forming an epitaxial film made of silicon on a surface of a silicon wafer in a trichlorosilane gas atmosphere; and setting the nitrogen concentration of the surface of the epitaxial film through inward diffusion from a nitride film on the epitaxial film, the nitride film being formed by subjecting the silicon wafer provided with the epitaxial film to heat treatment in a nitrogen atmosphere.
    Type: Application
    Filed: June 24, 2022
    Publication date: October 6, 2022
    Applicant: SUMCO CORPORATION
    Inventors: Kazuya KODANI, Toshiaki ONO, Kazuhisa TORIGOE
  • Patent number: 11462409
    Abstract: An epitaxial silicon wafer includes: a silicon wafer doped with phosphorus as a dopant and having an electrical resistivity of less than 1.0 m ?·cm; and an epitaxial film formed on the silicon wafer. The silicon wafer includes: a main surface to which a (100) plane is inclined; and a [100] axis that is perpendicular to the (100) plane and inclined at an angle ranging from 0°30? to 0°55? in any direction with respect to an axis perpendicular to the main surface. The epitaxial silicon wafer has at most 1/cm2 of a density of a hillock defect generated thereon.
    Type: Grant
    Filed: August 7, 2017
    Date of Patent: October 4, 2022
    Assignee: SUMCO CORPORATION
    Inventors: Naoya Nonaka, Tadashi Kawashima, Katsuya Ookubo
  • Patent number: 11456168
    Abstract: Provided is a method of lapping a semiconductor wafer, which can suppress the formation of a ring-shaped pattern in a nanotopography map. The method of lapping a semiconductor wafer includes: a stopping step of stopping lapping of a semiconductor wafer; a reversing step of reversing surfaces of the semiconductor wafer facing a upper plate and a lower plate after the stopping step; and a resuming step of resuming lapping of the semiconductor wafer after the reversing step while maintaining the reversal of the surfaces facing the plates.
    Type: Grant
    Filed: May 1, 2017
    Date of Patent: September 27, 2022
    Assignee: SUMCO CORPORATION
    Inventors: Daisuke Hashimoto, Satoshi Matagawa, Tomohiro Hashii
  • Publication number: 20220301949
    Abstract: A method of measuring the concentration of Fe in a p-type silicon wafer by an SPV method enabling improvement in the measurement accuracy for Fe concentrations of 1×109/cm3 or less. The method of measuring the concentration of Fe in a p-type silicon wafer includes measuring an Fe concentration in the p-type silicon wafer based on measurement using an SPV method. The measurement is performed in an atmosphere in which the total concentration of Na+, NH4+, and K+ is 1.750 ?g/m3 or less, and the total concentration of F?, Cl?, NO2?, PO43?, Br?, NO3?, and SO42? is 0.552 ?g/m3 or less.
    Type: Application
    Filed: June 7, 2022
    Publication date: September 22, 2022
    Applicant: SUMCO CORPORATION
    Inventors: Shinya FUKUSHIMA, Takehiro TSUNEMORI
  • Publication number: 20220290323
    Abstract: There is provided a growing method for monocrystalline silicon by a Czochralski process, the method including: pulling the monocrystalline silicon while rotating the monocrystalline silicon; and dropping a granular dopant onto a liquid surface of a silicon melt while a straight body of the monocrystalline silicon is being pulled, in which in the dropping of the dopant, a dropping position of the granular dopant is set above a region where a flow away from the straight body is dominant in the liquid surface of the silicon melt.
    Type: Application
    Filed: August 20, 2020
    Publication date: September 15, 2022
    Applicant: SUMCO CORPORATION
    Inventors: Norihito FUKATSU, Ryusuke YOKOYAMA
  • Patent number: 11441238
    Abstract: A method of manufacturing monocrystalline silicon by flowing inert gas in a chamber, applying horizontal magnetic field to a silicon melt in a quartz crucible, and pulling up monocrystalline silicon includes: forming a flow distribution of a flow of the inert gas flowing between a lower end of a heat shield and a surface of the silicon melt in the quartz crucible to be plane asymmetric with respect to a plane defined by a crystal pull-up axis of the pull-up device and an application direction of the horizontal magnetic field and rotationally asymmetric with respect to the crystal pull-up axis: maintaining the formed plane asymmetric and rotationally asymmetric flow distribution in a magnetic-field-free state until a silicon material in the quartz crucible is completely melted; and applying the horizontal magnetic field to the completely melted silicon material and starting pulling up the monocrystalline silicon.
    Type: Grant
    Filed: February 27, 2019
    Date of Patent: September 13, 2022
    Assignee: SUMCO CORPORATION
    Inventors: Ryusuke Yokoyama, Hideki Sakamoto, Wataru Sugimura
  • Patent number: 11440157
    Abstract: An inner-periphery-side cutoff part where a polishing surface of an upper plate inclines upward toward an inner periphery part of the upper plate and an inner-periphery-side cutoff part where a polishing surface of a lower plate inclines downward toward an inner periphery part of the lower plate are respectively formed on the respective inner periphery parts of the upper plate and the lower plate, or an outer-periphery-side cutoff part where the polishing surface of the upper plate inclines upward toward an outer periphery part of the upper plate and an outer-periphery-side cutoff part where the polishing surface of the lower plate inclines downward toward an outer periphery part of the lower plate are respectively formed on the respective outer periphery parts of the upper plate and the lower plate, or all of them are formed thereon.
    Type: Grant
    Filed: May 11, 2017
    Date of Patent: September 13, 2022
    Assignee: SUMCO CORPORATION
    Inventor: Keisuke Esaki
  • Patent number: 11426775
    Abstract: A cleaning method includes a first removal step of causing an inert gas to which a pulsation is applied to flow into an exhaust pipe after a silicon single crystal doped with an n-type dopant is produced, to peel and remove a deposit; and a second removal step of causing an atmospheric air to which no pulsation is applied to flow into the exhaust pipe through a chamber to burn a part of the deposit with the atmospheric air, the part being not removable in the first removal step, and peel and remove a burned substance of the deposit.
    Type: Grant
    Filed: November 16, 2018
    Date of Patent: August 30, 2022
    Assignee: SUMCO CORPORATION
    Inventors: Koichi Maegawa, Takuya Yotsui, Satoru Hamakawa
  • Publication number: 20220267929
    Abstract: A deposit removing device disclosed herein removes a deposit that adheres to an exhaust pipe through which gas is exhausted from a chamber that manufactures a semiconductor crystal. The deposit removing device includes: a valve that opens and closes an exhaust outlet that communicates with the exhaust pipe; a sealing cover and a fixed table configured to store the valve, into which an inert gas is introduceable, and configured to isolate the exhaust outlet from the outside; and an exhaust outlet opening/closing portion that includes a cylinder for driving the valve and a cylinder for driving the sealing cover or the fixed table. The cylinder drives the valve to open and close the exhaust outlet, and the cylinder drives the sealing cover or the fixed table to introduce the atmosphere into the sealing cover.
    Type: Application
    Filed: May 28, 2020
    Publication date: August 25, 2022
    Applicant: SUMCO CORPORATION
    Inventors: Fukuo OGAWA, Takuya YOTSUI, Koichi MAEGAWA
  • Patent number: 11424129
    Abstract: The method of etching a boron-doped p-type silicon wafer includes preparing an etching gas by introducing an ozone-containing gas and hydrofluoric acid mist into a chamber and mixing them; and performing gas phase decomposition of a surface layer area of a boron-doped p-type silicon wafer with a resistivity of 0.016 ?cm or less by bringing the etching gas into contact with a surface of the boron-doped p-type silicon wafer; and further includes introducing the ozone-containing gas into the chamber at a flow rate of 3,000 sccm or more; and preparing the hydrofluoric acid mist by atomizing hydrofluoric acid with a hydrofluoric acid concentration of 41 mass % or more.
    Type: Grant
    Filed: December 12, 2018
    Date of Patent: August 23, 2022
    Assignee: SUMCO CORPORATION
    Inventors: Hirokazu Kato, Takafumi Yamashita
  • Patent number: 11421342
    Abstract: Provided is a method of decomposing a quartz sample, which includes contacting a liquid in which at least a part of a quartz sample to be analyzed is immersed with a gas generated from a mixed acid to decompose at least a part of the quartz sample, wherein the liquid is a liquid containing at least water; and the mixed acid is a mixed acid of hydrogen fluoride and sulfuric acid, and a mole fraction of sulfuric acid in the mixed acid ranges from 0.07 to 0.40.
    Type: Grant
    Filed: December 7, 2017
    Date of Patent: August 23, 2022
    Assignee: SUMCO CORPORATION
    Inventors: Hirokazu Kato, Takashi Muramatsu
  • Patent number: 11414780
    Abstract: The amount of gas evacuation from a reaction chamber of an apparatus for manufacturing epitaxial wafers is controlled to any one of: a first amount of gas evacuation when an epitaxial film formation process is performed in the reaction chamber; a second amount of gas evacuation smaller than the first amount of gas evacuation when a gate valve is opened to load or unload a wafer between the reaction chamber and a wafer transfer chamber; and a third amount of gas evacuation larger than the first amount of gas evacuation until a purge process for a gas in the reaction chamber is completed after the epitaxial film formation process is completed in the reaction chamber.
    Type: Grant
    Filed: November 5, 2018
    Date of Patent: August 16, 2022
    Assignee: SUMCO CORPORATION
    Inventors: Yu Minamide, Naoyuki Wada, Yasutaka Takemura
  • Publication number: 20220251726
    Abstract: Provided is an epitaxial growth apparatus which makes it possible to prevent the production of debris between a preheat ring and a lower liner without fracturing the preheat ring. The epitaxial growth apparatus includes: a chamber; an upper liner and a lower liner that are disposed on an inner wall of the chamber; a susceptor being provided inside the chamber; and a preheat ring that is disposed on a supporting portion protruding in an opening of the lower liner and is disposed on the outer circumference of the susceptor. The preheat ring is not supported by the supporting portion in at least a part of a region that is right above a region where the semiconductor wafer passes in a transfer path in which the semiconductor wafer is loaded into the chamber to be set on the susceptor.
    Type: Application
    Filed: May 13, 2020
    Publication date: August 11, 2022
    Applicant: SUMCO CORPORATION
    Inventors: Haku KOMORI, Kazuhiro NARAHARA
  • Publication number: 20220228262
    Abstract: A carrier is formed in ring shape having a bottom surface mounted on an upper surface of a susceptor, an upper surface that contacts and supports an outer edge of a back surface of the wafer, an outer peripheral side wall surface and an inner peripheral side wall surface, and a gas vent hole is provided to penetrate between a space partitioned by the wafer, the carrier and the susceptor and a back surface of the susceptor.
    Type: Application
    Filed: February 7, 2020
    Publication date: July 21, 2022
    Applicant: SUMCO CORPORATION
    Inventors: Naoyuki WADA, Yu MINAMIDE
  • Patent number: 11387151
    Abstract: Provided is a method of measuring the concentration of Fe in a p-type silicon wafer by an SPV method enabling improvement in the measurement accuracy for Fe concentrations of 1×109/cm3 or less. The method of measuring the concentration of Fe in a p-type silicon wafer includes measuring an Fe concentration in the p-type silicon wafer based on measurement using an SPV method. The measurement is performed in an atmosphere in which the total concentration of Na+, NH4+, and K+ is 1.750 ?g/m3 or less, and the total concentration of F?, Cl?, NO2?, PO43?, Br?, NO3?, and SO42? is 0.552 ?g/m3 or less.
    Type: Grant
    Filed: October 2, 2018
    Date of Patent: July 12, 2022
    Assignee: SUMCO CORPORATION
    Inventors: Shinya Fukushima, Takehiro Tsunemori
  • Patent number: 11377755
    Abstract: An n-type silicon single crystal production method of pulling up a silicon single crystal from a silicon melt containing red phosphorus as a principal dopant and growing the silicon single crystal by the Czochralski process, the method including: controlling electrical resistivity at a start position of a straight body portion of the silicon single crystal to 0.80 m?cm or more and 1.05 m?cm or less; and sequentially lowering the electrical resistivity of the silicon single crystal as the silicon single crystal is up and grown, thereby adjusting electrical resistivity of a part of the silicon single crystal to 0.5 m?m or more and less than 0.6 m?cm.
    Type: Grant
    Filed: March 29, 2018
    Date of Patent: July 5, 2022
    Assignee: SUMCO CORPORATION
    Inventors: Koichi Maegawa, Yasuhito Narushima, Yasufumi Kawakami, Fukuo Ogawa, Yuuji Tsutsumi
  • Patent number: 11371160
    Abstract: A seed crystal holder for pulling up a single crystal is made of a carbon fiber-reinforced carbon composite material, and has a substantially cylindrical shape with a hollow space having a shape matching an outer shape of a substantially rod-shaped seed crystal. A direction of carbon fibers at a part in contact with at least an outer peripheral surface of the seed crystal has isotropy as viewed from a central axis of the hollow space.
    Type: Grant
    Filed: September 30, 2020
    Date of Patent: June 28, 2022
    Assignee: SUMCO CORPORATION
    Inventor: Eiichi Kawasaki
  • Patent number: 11373858
    Abstract: Provided are abrasive grains, an evaluation method and a wafer manufacturing method. A predetermined amount of abrasive grains is prepared as an abrasive grain sample group, the grain diameter of individual abrasive grains in the abrasive grain sample group is measured, the number of abrasive grains in the abrasive grain sample group as a whole is counted, abrasive grains having a grain diameter equal to or smaller than a predetermined reference grain e diameter criterion which is smaller than the average grain diameter of the abrasive grain sample are defined as small grains and the number of the small grains is counted, a small grain ratio is calculated as the number ratio of the small grains occupied in the abrasive grain sample group as a whole, and a determination is made as to whether or not the small grain ratio is equal to or smaller than a predetermined threshold value.
    Type: Grant
    Filed: September 7, 2017
    Date of Patent: June 28, 2022
    Assignee: SUMCO CORPORATION
    Inventor: Makoto Funayama