Patents by Inventor Hiroshi Tsuge
Hiroshi Tsuge 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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Patent number: 10711369Abstract: The present invention provides a method for producing an SiC single crystal, enabling obtaining an SiC single crystal substrate in which a screw dislocation-reduced region is ensured in a wide range, and an SiC single crystal substrate. The SiC single crystal substrate is produced using a seed crystal having an off angle in the off orientation from a {0001} plane by a production method wherein in advance of a growth main step of performing crystal growth to form a facet {0001} plane in the crystal peripheral part on the crystal end face having grown thereon the bulk silicon carbide single crystal and obtain more than 50% of the thickness of the obtained SiC single crystal, a growth sub-step of growing the crystal at a higher nitrogen concentration than in the growth main step and at a growth atmosphere pressure of 3.9 to 39.9 kPa and a seed crystal temperature of 2,100° C. to less than 2,300° C. is included.Type: GrantFiled: December 4, 2015Date of Patent: July 14, 2020Assignee: SHOWA DENKO K.K.Inventors: Shinya Sato, Tatsuo Fujimoto, Masakazu Katsuno, Hiroshi Tsuge, Masashi Nakabayashi
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Publication number: 20190024257Abstract: Provided are: a silicon carbide single crystal substrate which is cut out from a silicon carbide bulk single crystal grown by the Physical Vapor Transport method; and a process for producing the same. The number of screw dislocations in one of the semicircle areas of the substrate is smaller than that in the other thereof, namely, the number of screw dislocations in a given area of the substrate is reduced. The semicircle areas of the substrate correspond respectively to the halves of the substrate.Type: ApplicationFiled: September 24, 2018Publication date: January 24, 2019Applicant: SHOWA DENKO K.K.Inventors: Shinya SATO, Tatsuo FUJIMOTO, Hiroshi TSUGE, Masakazu KATSUNO
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Patent number: 10119200Abstract: Provided are: a silicon carbide single crystal substrate which is cut out from a silicon carbide bulk single crystal grown by the Physical Vapor Transport method; and a process for producing the same. The number of screw dislocations in one of the semicircle areas of the substrate is smaller than that in the other thereof, namely, the number of screw dislocations in a given area of the substrate is reduced. The semicircle areas of the substrate correspond respectively to the halves of the substrate.Type: GrantFiled: November 15, 2013Date of Patent: November 6, 2018Assignee: SHOWA DENKO K.K.Inventors: Shinya Sato, Tatsuo Fujimoto, Hiroshi Tsuge, Masakazu Katsuno
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Patent number: 10066316Abstract: The present invention provides a method of raising the rate of reduction of the dislocation density accompanying growth of an SiC single crystal to counter the increase in the threading screw dislocations formed near the interface of the seed crystal and grown SiC single crystal and thereby produce an SiC single-crystal ingot with a small threading screw dislocation density from the initial stage of growth.Type: GrantFiled: February 18, 2016Date of Patent: September 4, 2018Assignee: SHOWA DENKO K.K.Inventors: Komomo Tani, Takayuki Yano, Tatsuo Fujimoto, Hiroshi Tsuge, Kazuhito Kamei, Kazuhiko Kusunoki, Kazuaki Seki
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Publication number: 20180066380Abstract: The present invention provides a method of raising the rate of reduction of the dislocation density accompanying growth of an SiC single crystal to counter the increase in the threading screw dislocations formed near the interface of the seed crystal and grown SiC single crystal and thereby produce an SiC single-crystal ingot with a small threading screw dislocation density from the initial stage of growth.Type: ApplicationFiled: February 18, 2016Publication date: March 8, 2018Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Komomo TANI, Takayuki YANO, Tatsuo FUJIMOTO, Hiroshi TSUGE, Kazuhito KAMEI, Kazuhiko KUSUNOKI, Kazuaki SEKI
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Publication number: 20170342593Abstract: The present invention provides a method for producing an SiC single crystal, enabling obtaining an SiC single crystal substrate in which a screw dislocation-reduced region is ensured in a wide range, and an SiC single crystal substrate. The SiC single crystal substrate is produced using a seed crystal having an off angle in the off orientation from a {0001} plane by a production method wherein in advance of a growth main step of performing crystal growth to form a facet {0001} plane in the crystal peripheral part on the crystal end face having grown thereon the bulk silicon carbide single crystal and obtain more than 50% of the thickness of the obtained SiC single crystal, a growth sub-step of growing the crystal at a higher nitrogen concentration than in the growth main step and at a growth atmosphere pressure of 3.9 to 39.9 kPa and a seed crystal temperature of 2,100° C. to less than 2,300° C. is included.Type: ApplicationFiled: December 4, 2015Publication date: November 30, 2017Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Shinya SATO, Tatsuo FUJIMOTO, Masakazu KATSUNO, Hiroshi TSUGE, Masashi NAKABAYASHI
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Patent number: 9777403Abstract: A single-crystal silicon carbide and a single-crystal silicon carbide wafer of good-quality are disclosed that are low in dislocations, micropipes and other crystal defects and enable high yield and high performance when applied to a device, wherein the ratio of doping element concentrations on opposite sides in the direction of crystal growth of the interface between the seed crystal and the grown crystal is 5 or less and the doping element concentration of the grown crystal in the vicinity of the seed crystal is 2×1019 cm?3 to 6×1020 cm?3.Type: GrantFiled: October 14, 2009Date of Patent: October 3, 2017Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Masashi Nakabayashi, Tatsuo Fujimoto, Masakazu Katsuno, Hiroshi Tsuge
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Patent number: 9691607Abstract: Disclosed is a process for producing an epitaxial single-crystal silicon carbide substrate by epitaxially growing a silicon carbide film on a single-crystal silicon carbide substrate by chemical vapor deposition. The step of crystal growth in the process comprises a main crystal growth step, which mainly occupies the period of epitaxial growth, and a secondary crystal growth step, in which the growth temperature is switched between a set growth temperature (T0) and a set growth temperature (T2) which are respectively lower and higher than a growth temperature (T1) used in the main crystal growth step. The basal plane dislocations of the single-crystal silicon carbide substrate are inhibited from being transferred to the epitaxial film. Thus, a high-quality epitaxial film is formed.Type: GrantFiled: April 7, 2011Date of Patent: June 27, 2017Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Takashi Aigo, Hiroshi Tsuge, Taizo Hoshino, Tatsuo Fujimoto, Masakazu Katsuno, Masashi Nakabayashi, Hirokatsu Yashiro
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Patent number: 9590479Abstract: Disclosed is a stator for a rotating electrical machine, which includes a stator core having a plurality of slots, and a plurality of coils. Each of the coils has a first inserting section and a second inserting section, which are inserted into two slots which form a pair, a first coil end, and a second coil end. The first and/or the second coil end has a twisted portion and a bent portion. The twisted portion is formed by twisting the coil end at a part close to the first inserting section. The bent portion is formed by bending, at a part close to the second inserting section, the coil end such that the coil end is laid flat.Type: GrantFiled: March 8, 2011Date of Patent: March 7, 2017Assignee: KABUSHIKI KAISHA TOYOTA JIDOSHOKKIInventors: Hiroshi Tsuge, Kazuyuki Yamaguchi
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Patent number: 9248529Abstract: An assembling apparatus (1) comprises a shaft member (3) having a linear assembling function and a rotational assembling function, a base (2) supporting the shaft member (3) to be movable in the axial direction and rotatable axially, and a drive unit moving in an axial direction and axially rotating the shaft member (3).Type: GrantFiled: May 9, 2011Date of Patent: February 2, 2016Assignee: KABUSHIKI KAISHA TOYOTA JIDOSHOKKIInventors: Noriyasu Watanabe, Hirotsugu Miyaki, Hiroshi Tsuge, Kazuyuki Yamaguchi
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Patent number: 9234297Abstract: Provided are a method for manufacturing a SiC single crystal having high crystal quality and, in particular, extremely low screw dislocation density and a SiC single crystal ingot obtained by the method. In particular, provided is a silicon carbide single crystal substrate that is a substrate cut from a bulk silicon carbide single crystal grown by the Physical Vapior Transport (PVT) method, in which the screw dislocation density is smaller in the peripheral region than in the center region, so that screw dislocations are partially reduced. The method is a method for manufacturing a SiC single crystal by the PVT method using a seed crystal and the ingot is a SiC single crystal ingot obtained by the method. Particularly, the silicon carbide single crystal substrate is a silicon carbide single crystal substrate in which when, by representing the diameter of the substrate as R, a center circle region having a diameter of 0.Type: GrantFiled: August 29, 2012Date of Patent: January 12, 2016Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Shinya Sato, Tatsuo Fujimoto, Hiroshi Tsuge, Masakazu Katsuno
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Publication number: 20150267319Abstract: Provided are: a silicon carbide single crystal substrate which is cut out from a silicon carbide bulk single crystal grown by the Physical Vapor Transport method; and a process for producing the same. The number of screw dislocations in one of the semicircle areas of the substrate is smaller than that in the other thereof, namely, the number of screw dislocations in a given area of the substrate is reduced. The semicircle areas of the substrate correspond respectively to the halves of the substrate.Type: ApplicationFiled: November 15, 2013Publication date: September 24, 2015Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Shinya Sato, Tatsuo Fujimoto, Hiroshi Tsuge, Masakazu Katsuno
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Patent number: 9068277Abstract: The invention provides an apparatus for manufacturing good quality single-crystal silicon carbide stably without formation of cracks and the like, which apparatus comprises: at least a crucible for accommodating silicon carbide feedstock powder and seed crystal; heat insulation material installed around the crucible; and a heating device for heating the crucible, wherein the outer profile of the crucible includes at least one region of narrower diameter than a vertically adjacent region, insulation material is also installed in the space left by the diameter difference, and thickness of the insulation material at the narrower diameter region is greater than that of the insulation material at the vertically adjacent region. The apparatus for manufacturing single-crystal silicon carbide enables precise control of the temperature gradient inside the crucible, thereby enabling manufacture of good quality single-crystal silicon carbide.Type: GrantFiled: April 1, 2009Date of Patent: June 30, 2015Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Masashi Nakabayashi, Tatsuo Fujimoto, Hiroshi Tsuge, Masakazu Katsuno, Noboru Ohtani
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Publication number: 20150075422Abstract: The present invention provides an epitaxial SiC monocrystalline substrate having a high quality epitaxial film suppressed in occurrence of step bunching in epitaxial growth using a substrate with an off angle of 6° or less and a method of production of the same, that is, an epitaxial silicon carbide monocrystalline substrate comprised of a silicon carbide monocrystalline substrate with an off angle of 6° or less on which a silicon carbide monocrystalline thin film is formed, the epitaxial silicon carbide monocrystalline substrate characterized in that the silicon carbide monocrystalline thin film has a surface with a surface roughness (Ra value) of 0.5 nm or less and a method of production of the same.Type: ApplicationFiled: November 19, 2014Publication date: March 19, 2015Inventors: Takashi Aigo, Hiroshi Tsuge, Taizo Hoshino, Tatsuo Fujimoto, Masakasu Katsuno, Masashi Nakabayashi, Hirokatsu Yashiro
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Patent number: 8936680Abstract: The present invention, which provides a crucible for producing single-crystal silicon carbide, and a production apparatus and a production method for single-crystal silicon carbide, which are capable of stably growing a single-crystal silicon carbide ingot good in crystallinity at high yield, is a crucible for producing single-crystal silicon carbide having a crucible vessel for holding silicon carbide raw material and a crucible cover for attaching a seed crystal and is adapted to sublimate a silicon carbide raw material in the crucible vessel to supply silicon carbide sublimation gas onto a seed crystal attached to the crucible cover and grow single-crystal silicon carbide on the seed crystal, which crucible for producing single-crystal silicon carbide is provided in the crucible vessel and the crucible cover with threaded portions to be screwed together and is provided with a sublimation gas discharge groove or grooves capable of regulating flow rate by relative rotation of the threaded portions; and is aType: GrantFiled: February 25, 2010Date of Patent: January 20, 2015Assignee: Nippon Steel & Sumitomo Metal CorporationInventors: Masakazu Katsuno, Tatsuo Fujimoto, Hiroshi Tsuge, Masashi Nakabayashi
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Patent number: 8927396Abstract: An object of the present invention is to provide a production process of an epitaxial silicon carbide single crystal substrate having a high-quality silicon carbide single crystal thin film reduced in the surface defect and the like on a silicon carbide single crystal substrate with a small off-angle. According to the present invention, in the production process of an epitaxial silicon carbide single crystal substrate having a high-quality silicon carbide single crystal thin film reduced in the surface defect and the like on a silicon carbide single crystal substrate with an off-angle of 4° or less, pretreatment etching to a depth of 0.1 to 1 ?m is performed at a temperature of 1,550 to 1,650° C. by flowing a gas containing silicon and chlorine together with a hydrogen gas such that the silicon atom concentration becomes from 0.0001 to 0.01% based on hydrogen atoms in the hydrogen gas, and thereafter, an epitaxial layer is formed.Type: GrantFiled: November 15, 2011Date of Patent: January 6, 2015Assignee: Nippon Steel & Sumitomo Metal CorporationInventors: Takashi Aigo, Hiroshi Tsuge, Masakazu Katsuno, Tatsuo Fujimoto, Hirokatsu Yashiro
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Publication number: 20140363607Abstract: Provided are a method for manufacturing a SiC single crystal having high crystal quality and, in particular, extremely low screw dislocation density and a SiC single crystal ingot obtained by the method. In particular, provided is a silicon carbide single crystal substrate that is a substrate cut from a bulk silicon carbide single crystal grown by the Physical Vapior Transport (PVT) method, in which the screw dislocation density is smaller in the peripheral region than in the center region, so that screw dislocations are partially reduced. The method is a method for manufacturing a SiC single crystal by the PVT method using a seed crystal and the ingot is a SiC single crystal ingot obtained by the method. Particularly, the silicon carbide single crystal substrate is a silicon carbide single crystal substrate in which when, by representing the diameter of the substrate as R, a center circle region having a diameter of 0.Type: ApplicationFiled: August 29, 2012Publication date: December 11, 2014Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Shinya Sato, Tatsuo Fujimoto, Hiroshi Tsuge, Masakazu Katsuno
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Patent number: 8901570Abstract: Provided is an epitaxial silicon carbide single-crystal substrate in which a silicon carbide epitaxial film having excellent in-plane uniformity of doping density is disposed on a silicon carbide single-crystal substrate having an off angle that is between 1° to 6°. The epitaxial film is grown by repeating a dope layer that is 0.5 ?m or less and a non-dope layer that is 0.1 ?m or less. The dope layer is formed with the ratio of the number of carbon atoms to the number of silicon atoms (C/Si ratio) in a material gas being 1.5 to 2.0, and the non-dope layer is formed with the C/Si ratio being 0.5 or more but less than 1.5. The resulting epitaxial silicon carbide single-crystal substrate comprises a high-quality silicon carbide epitaxial film, which has excellent in-plane uniformity of doping density, on a silicon carbide single-crystal substrate having a small off angle.Type: GrantFiled: May 10, 2011Date of Patent: December 2, 2014Assignee: Nippon Steel & Sumitomo Metal CorporationInventors: Takashi Aigo, Hiroshi Tsuge, Taizo Hoshino, Tatsuo Fujimoto, Masakazu Katsuno, Masashi Nakabayashi, Hirokatsu Yashiro
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Publication number: 20130320357Abstract: Provided are an epitaxial silicon carbide single crystal substrate having a high-quality silicon carbide single crystal thin film with less stacking faults on a silicon carbide single crystal substrate and a production method therefor. The epitaxial silicon carbide single crystal substrate is produced by growing a silicon carbide epitaxial layer on a silicon carbide single crystal substrate having an off-angle of 4° or less so that the number of stacking faults emitting light at wavelengths ranging from 400 to 600 nm by photoluminescence on the substrate is less than 10/cm2 in total. Additionally, the method for producing the epitaxial silicon carbide single crystal substrate forms the epitaxial layer by using chlorosilane as a silicon-based material gas and hydrocarbon gas as a carbon-based gas, at a growth temperature of 1600° C. to 1700° C., at a C/Si ratio of 0.5 to 1.0, and at a growth rate of 1 to 3 ?m/hr.Type: ApplicationFiled: April 20, 2012Publication date: December 5, 2013Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Takashi Aigo, Hiroshi Tsuge, Masakazu Katsuno, Tatsuo Fujimoto, Hirokatsu Yashiro, Wataru Ito
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Publication number: 20130217213Abstract: An object of the present invention is to provide a production process of an epitaxial silicon carbide single crystal substrate having a high-quality silicon carbide single crystal thin film reduced in the surface defect and the like on a silicon carbide single crystal substrate with a small off-angle. According to the present invention, in the production process of an epitaxial silicon carbide single crystal substrate having a high-quality silicon carbide single crystal thin film reduced in the surface defect and the like on a silicon carbide single crystal substrate with an off-angle of 4° or less, pretreatment etching to a depth of 0.1 to 1 ?m is performed at a temperature of 1,550 to 1,650° C. by flowing a gas containing silicon and chlorine together with a hydrogen gas such that the silicon atom concentration becomes from 0.0001 to 0.01% based on hydrogen atoms in the hydrogen gas, and thereafter, an epitaxial layer is formed.Type: ApplicationFiled: November 15, 2011Publication date: August 22, 2013Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Takashi Aigo, Hiroshi Tsuge, Masakazu Katsuno, Tatsuo Fujimoto, Hirokatsu Yashiro