Patents by Inventor Hiroaki Sumitani
Hiroaki Sumitani 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: 10508362Abstract: A substrate mounting member according to the present invention is a member for mounting a SiC substrate for epitaxial growth, which includes a wafer plate including a SiC polycrystal, and a supporting plate configured to be placed on the wafer plate, include no SiC polycrystal and have a surface serving as a SiC substrate placing surface, the surface being on the side opposite to a surface in contact with the wafer plate, and in which a thickness h [mm] of the supporting plate satisfies an expression h4?3 pa4(1?v2){(5+v)/(1+v)}/16E when a force applied to a unit area of the supporting plate by a self-weight of the supporting plate and by the SiC substrate is represented as p [N/mm2], a radius of the supporting plate as a [mm], a Poisson's ratio as v and a Young's modulus as E [MPa].Type: GrantFiled: November 22, 2016Date of Patent: December 17, 2019Assignee: Mitsubishi Electric CorporationInventors: Kenichi Hamano, Hiroaki Sumitani
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Publication number: 20170283984Abstract: A substrate mounting member according to the present invention is a member for mounting a SiC substrate for epitaxial growth, which includes a wafer plate including a SiC polycrystal, and a supporting plate configured to be placed on the wafer plate, include no SiC polycrystal and have a surface serving as a SiC substrate placing surface, the surface being on the side opposite to a surface in contact with the wafer plate, and in which a thickness h [mm] of the supporting plate satisfies an expression h4?3pa4(1?v2){(5+v)/(1+v)}16E when a force applied to a unit area of the supporting plate by a self-weight of the supporting plate and by the SiC substrate is represented as p [N/mm2], a radius of the supporting plate as a [mm], a Poisson's ratio as v and a Young's modulus as E [MPa].Type: ApplicationFiled: November 22, 2016Publication date: October 5, 2017Applicant: Mitsubishi Electric CorporationInventors: Kenichi HAMANO, Hiroaki SUMITANI
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Patent number: 9059193Abstract: A silicon carbide semiconductor element, including: i) an n-type silicon carbide substrate doped with a dopant, such as nitrogen, at a concentration C, wherein the substrate has a lattice constant that decreases with doping; ii) an n-type silicon carbide epitaxially-grown layer doped with the dopant, but at a smaller concentration than the substrate; and iii) an n-type buffer layer doped with the dopant, and arranged between the substrate and the epitaxially-grown layer, wherein the buffer layer has a multilayer structure in which two or more layers having the same thickness are laminated, and is configured such that, based on a number of layers (N) in the multilayer structure, a doping concentration of a K-th layer from a silicon carbide epitaxially-grown layer side is C·K/(N+1).Type: GrantFiled: December 27, 2010Date of Patent: June 16, 2015Assignee: Mitsubishi Electric CorporationInventors: Kenichi Ohtsuka, Kenichi Kuroda, Hiroshi Watanabe, Naoki Yutani, Hiroaki Sumitani
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Patent number: 8679952Abstract: A method is provided in order to manufacture a silicon carbide epitaxial wafer whose surface flatness is very good and has a very low density of carrot defects and triangular defects arising after epitaxial growth. The silicon carbide epitaxial wafer is manufactured by a first step of annealing a silicon carbide bulk substrate that is tilted less than 5 degrees from <0001> face, in a reducing gas atmosphere at a first temperature T1 for a treatment time t, a second step of reducing the temperature of the substrate in the reducing gas atmosphere, and a third step of performing epitaxial growth at a second temperature T2 below the annealing temperature T1 in the first step, while supplying at least a gas including silicon atoms and a gas including carbon atoms.Type: GrantFiled: March 18, 2011Date of Patent: March 25, 2014Assignee: Mitsubishi Electric CorporationInventors: Nobuyuki Tomita, Kenichi Hamano, Masayoshi Tarutani, Yoichiro Mitani, Takeharu Kuroiwa, Masayuki Imaizumi, Hiroaki Sumitani, Kenichi Ohtsuka, Tomoaki Furusho, Takao Sawada, Yuji Abe
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Publication number: 20130126906Abstract: A method is provided in order to manufacture a silicon carbide epitaxial wafer whose surface flatness is very good and has a very low density of carrot defects and triangular defects arising after epitaxial growth. The silicon carbide epitaxial wafer is manufactured by a first step of annealing a silicon carbide bulk substrate that is tilted less than 5 degrees from <0001> face, in a reducing gas atmosphere at a first temperature T1 for a treatment time t, a second step of reducing the temperature of the substrate in the reducing gas atmosphere, and a third step of performing epitaxial growth at a second temperature T2 below the annealing temperature T1 in the first step, while supplying at least a gas including silicon atoms and a gas including carbon atoms.Type: ApplicationFiled: March 18, 2011Publication date: May 23, 2013Applicant: Mitsubishi Electric CorporationInventors: Nobuyuki Tomita, Kenichi Hamano, Masayoshi Tarutani, Yoichiro Mitani, Takeharu Kuroiwa, Masayuki Imaizumi, Hiroaki Sumitani, Kenichi Ohtsuka, Tomoaki Furusho, Takao Sawada, Yuji Abe
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Publication number: 20120241766Abstract: A silicon carbide semiconductor element, including: i) an n-type silicon carbide substrate doped with a dopant, such as nitrogen, at a concentration C, wherein the substrate has a lattice constant that decreases with doping; ii) an n-type silicon carbide epitaxially-grown layer doped with the dopant, but at a smaller concentration than the substrate; and iii) an n-type buffer layer doped with the dopant, and arranged between the substrate and the epitaxially-grown layer, wherein the buffer layer has a multilayer structure in which two or more layers having the same thickness are laminated, and is configured such that, based on a number of layers (N) in the multilayer structure, a doping concentration of a K-th layer from a silicon carbide epitaxially-grown layer side is C·K/(N+1).Type: ApplicationFiled: December 27, 2010Publication date: September 27, 2012Applicant: Mitsubishi Electric CorporationInventors: Kenichi Ohtsuka, Kenichi Kuroda, Hiroshi Watanabe, Naoki Yutani, Hiroaki Sumitani
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Patent number: 5953492Abstract: The X-ray mask manufactured according to the present invention can solve a problem that the thin film stress of the X-ray absorber cannot be made to be zero although the mean thin film stress throughout the X-ray absorber can be made to be zero. The thin film stress distribution over the X-ray absorber 4 after the X-ray absorber 4 has been formed on a silicon substrate 1 is measured, and then inputs of electric power to heaters 9a, 9b and 9c of a hot plate 8 are changed so as to heat the X-ray absorber 4 to temperatures according to a specified temperature distribution with which the thin film stress throughout the X-ray absorber can be made to be zero.Type: GrantFiled: November 20, 1997Date of Patent: September 14, 1999Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hideki Yabe, Kenji Marumoto, Sunao Aya, Koji Kise, Hiroaki Sumitani, Takashi Hifumi, Hiroshi Watanabe
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Patent number: 5834142Abstract: The X-ray mask manufactured according to the present invention can solve a problem that the thin film stress of the X-ray absorber cannot be made to be zero although the mean thin film stress throughout the X-ray absorber can be made to be zero. The thin film stress distribution over the X-ray absorber 4 after the X-ray absorber 4 has been formed on a silicon substrate 1 is measured, and then inputs of electric power to heaters 9a, 9b and 9c of a hot plate 8 are changed so as to heat the X-ray absorber 4 to temperatures according to a specified temperature distribution with which the thin film stress throughout the X-ray absorber can be made to be zero.Type: GrantFiled: October 25, 1996Date of Patent: November 10, 1998Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hideki Yabe, Kenji Marumoto, Sunao Aya, Koji Kise, Hiroaki Sumitani, Takashi Hifumi, Hiroshi Watanabe
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Patent number: 4841489Abstract: A method of imaging an object by the ultrasonic or electromagnetic wave by mechanically or electronically scanning the ultrasonic or electromagnetic wave transmitting/receiving system to transmit the ultrasonic or electromagnetic wave beam spreading in space of the object and using the trace (TOF locus) from the transmission to the reception while receiving the reflected wave from the object, and sequentially reproducing the line image at the central line of the synthetic aperture range using the received signal group from the scanning points in the synthetic aperture range to sequentially image the area to be imaged while scanning the ultrasonic or electromagnetic wave transmitting/receiving system. An imaging apparatus applied with the method has a relatively simple hardware structure for reproducing the image and is also able to perform the operation in real time.Type: GrantFiled: December 24, 1986Date of Patent: June 20, 1989Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Yoshihiko Ozaki, Hiroaki Sumitani, Toshimasa Tomoda, Fumihide Sato, Kenji Kusano