Patents by Inventor Akira Miyasaka
Akira Miyasaka 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: 11906569Abstract: A semiconductor wafer evaluation apparatus brings a contact maker (mercury liquefied at room temperature), as a Schottky electrode, into contact with a semiconductor wafer, intermittently applies a voltage from a pulse power supply, and evaluates the state (kinds, density) of point defects by an evaluation means based on the status of the electrostatic capacity of the semiconductor wafer. In this manner, the state (kinds, density) of the point defects in the plane of a large-diameter semiconductor wafer is directly evaluated using a large table.Type: GrantFiled: November 5, 2021Date of Patent: February 20, 2024Assignee: SHOWA DENKO K.K.Inventors: Koichi Murata, Isaho Kamata, Hidekazu Tsuchida, Akira Miyasaka
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Publication number: 20220146564Abstract: A semiconductor wafer evaluation apparatus brings a contact maker (mercury liquefied at room temperature), as a Schottky electrode, into contact with a semiconductor wafer, intermittently applies a voltage from a pulse power supply, and evaluates the state (kinds, density) of point defects by an evaluation means based on the status of the electrostatic capacity of the semiconductor wafer. In this manner, the state (kinds, density) of the point defects in the plane of a large-diameter semiconductor wafer is directly evaluated using a large table.Type: ApplicationFiled: November 5, 2021Publication date: May 12, 2022Applicant: SHOWA DENKO K.K.Inventors: Koichi Murata, Isaho KAMATA, Hidekazu TSUCHIDA, Akira MIYASAKA
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Patent number: 10865500Abstract: A SiC epitaxial wafer having a SiC epitaxial layer formed on a SiC single crystal substrate having an offset angle of 4 degrees or less in a<11-20>direction from a (0001) plane. A trapezoidal defect included in the SiC epitaxial wafer includes an inverted trapezoidal defect in which a length of a lower base on a downstream side of a step flow is equal to or less than a length of an upper base on an upstream side of the step flow. Also disclosed is a method for manufacturing the SiC epitaxial wafer.Type: GrantFiled: February 16, 2016Date of Patent: December 15, 2020Assignee: SHOWA DENKO K.K.Inventors: Jun Norimatsu, Akira Miyasaka, Yoshiaki Kageshima, Koji Kamei, Daisuke Muto
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Patent number: 10774444Abstract: This method of producing a SiC epitaxial wafer having an epitaxial layer on a SiC single crystal substrate, and includes: when performing crystal growth of the epitaxial layer, a step of forming a part of an epitaxial layer under first conditions at an initial stage where the crystal growth is started; and a step of forming a part of a SiC epitaxial layer under second conditions in which a Cl/Si ratio is decreased and a C/Si ratio is increased in comparison to those in the first conditions, wherein the C/Si ratio is equal to or less than 0.6 and the Cl/Si ratio is equal to or more than 5.0 in the first conditions.Type: GrantFiled: December 12, 2016Date of Patent: September 15, 2020Assignee: SHOWA DENKO K.K.Inventors: Daisuke Muto, Akira Miyasaka
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Patent number: 10494737Abstract: The SiC epitaxial wafer-producing apparatus according to the invention includes a mounting plate having a concave accommodation portion, a satellite that is provided in the concave accommodation portion and has an upper surface on which a SiC substrate is placed, and a carbon member that is provided in the concave accommodation portion at a position which is lower than the SiC substrate and does not come into contact with the SiC substrate.Type: GrantFiled: October 30, 2014Date of Patent: December 3, 2019Assignee: SHOWA DENKO K.K.Inventors: Jun Norimatsu, Akira Miyasaka, Yoshiaki Kageshima
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Patent number: 10176987Abstract: A SiC epitaxial wafer including: a SiC epitaxial layer that is formed on a SiC substrate having an off angle, wherein the surface density of triangular defects, in which a distance from a starting point to an opposite side in a horizontal direction is equal to or greater than (a thickness of the SiC epitaxial layer/tan(x))×90% and equal to or less than (the thickness of the SiC epitaxial layer/tan(x))×110%, in the SiC epitaxial layer is in the range of 0.05 pieces/cm2 to 0.5 pieces/cm2 (where x indicates the off angle).Type: GrantFiled: May 4, 2017Date of Patent: January 8, 2019Assignee: SHOWA DENKO K.K.Inventors: Akira Miyasaka, Yutaka Tajima, Yoshiaki Kageshima, Daisuke Muto, Kenji Momose
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Publication number: 20180371641Abstract: This method of producing a SiC epitaxial wafer having an epitaxial layer on a SiC single crystal substrate, and includes: when performing crystal growth of the epitaxial layer, a step of forming a part of an epitaxial layer under first conditions at an initial stage where the crystal growth is started; and a step of forming a part of a SiC epitaxial layer under second conditions in which a Cl/Si ratio is decreased and a C/Si ratio is increased in comparison to those in the first conditions, wherein the C/Si ratio is equal to or less than 0.6 and the Cl/Si ratio is equal to or more than 5.0 in the first conditions.Type: ApplicationFiled: December 12, 2016Publication date: December 27, 2018Applicant: SHOWA DENKO K.K.Inventors: Daisuke MUTO, Akira MIYASAKA
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Publication number: 20180016706Abstract: An SiC epitaxial wafer having an SiC epitaxial layer formed on an SiC single crystal substrate having an offset angle of 4 degrees or less in a <11-20> direction from a (0001) plane. A trapezoidal defect included in the SiC epitaxial wafer includes an inverted trapezoidal defect in which a length of a lower base on a downstream side of a step flow is equal to or less than a length of an upper base on an upstream side of the step flow. Also disclosed is a method for manufacturing the SiC epitaxial wafer.Type: ApplicationFiled: February 16, 2016Publication date: January 18, 2018Applicant: SHOWA DENKO K.K.Inventors: Jun NORIMATSU, Akira MIYASAKA, Yoshiaki KAGESHIMA, Koji KAMEI, Daisuke MUTO
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Publication number: 20170233893Abstract: A SiC epitaxial wafer including: a SiC epitaxial layer that is formed on a SiC substrate having an off angle, wherein the surface density of triangular defects, in which a distance from a starting point to an opposite side in a horizontal direction is equal to or greater than (a thickness of the SiC epitaxial layer/tan(x))×90% and equal to or less than (the thickness of the SiC epitaxial layer/tan(x))×110%, in the SiC epitaxial layer is in the range of 0.05 pieces/cm2 to 0.5 pieces/cm2 (where x indicates the off angle).Type: ApplicationFiled: May 4, 2017Publication date: August 17, 2017Applicant: SHOWA DENKO K.K.Inventors: Akira MIYASAKA, Yutaka TAJIMA, Yoshiaki KAGESHIMA, Daisuke MUTO, Kenji MOMOSE
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Patent number: 9679767Abstract: Provided is a method of manufacturing a SiC epitaxial wafer including a SiC epitaxial layer on a SiC substrate using a SiC-CVD furnace which is installed in a glove box. The method includes a SiC substrate placement step of placing the SiC substrate in the SiC-CVD furnace while circulating gas in the glove box.Type: GrantFiled: June 19, 2013Date of Patent: June 13, 2017Assignee: SHOWA DENKO K.K.Inventors: Akira Miyasaka, Yutaka Tajima, Yoshiaki Kageshima, Daisuke Muto, Kenji Momose
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Publication number: 20160312381Abstract: The SiC epitaxial wafer-producing apparatus according to the invention includes a mounting plate having a concave accommodation portion, a satellite that is provided in the concave accommodation portion and has an upper surface on which a SiC substrate is placed, and a carbon member that is provided in the concave accommodation portion at a position which is lower than the SiC substrate and does not come into contact with the SiC substrate.Type: ApplicationFiled: October 30, 2014Publication date: October 27, 2016Applicant: SHOWA DENKO K.K.Inventors: Jun NORIMATSU, Akira MIYASAKA, Yoshiaki KAGESHIMA
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Publication number: 20150162187Abstract: Provided is a method of manufacturing a SiC epitaxial wafer including a SiC epitaxial layer on a SiC substrate using a SiC-CVD furnace which is installed in a glove box. The method includes a SiC substrate placement step of placing the SiC substrate in the SiC-CVD furnace while circulating gas in the glove box.Type: ApplicationFiled: June 19, 2013Publication date: June 11, 2015Applicant: SHOWA DENKO K.K.Inventors: Akira Miyasaka, Yutaka Tajima, Yoshiaki Kageshima, Daisuke Muto, Kenji Momose
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Patent number: 8064465Abstract: In a virtual LAN, a packet forwarding apparatus forwards IP packets and L2 packets using a single switch. The packet forwarding apparatus includes a switch that switches a media access control (MAC) packet using a MAC address of the MAC packet, and a packet format converter. The packet format converter converts a packet from an input and output unit into a packet having a MAC address according to information from the input and output unit, and converts a packet output from the switch to the input and output unit to a packet format compatible with the input and output unit according to the information of the input and output unit.Type: GrantFiled: July 7, 2006Date of Patent: November 22, 2011Assignee: Fujitsu LimitedInventors: Masaki Deguchi, Akira Miyasaka
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Patent number: 7972010Abstract: A projector that includes: a projector body including an image optical system for image creation and projection, and an image circuit that operates the image optical system; an auxiliary input unit that forms an auxiliary signal for exercising control over an operating state of the projector body; and a distribution unit that transfers the auxiliary signal formed by the auxiliary input unit to the image circuit and an external display unit.Type: GrantFiled: June 20, 2006Date of Patent: July 5, 2011Assignee: Seiko Epson CorporationInventor: Akira Miyasaka
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Patent number: 7867060Abstract: Disclosed is a polishing method for polishing a surface of a structure for magnetic-head manufacture by CMP in the process of manufacturing a magnetic head using a ceramic substrate made of a ceramic material containing AlTiC, the structure including the ceramic substrate and one or more layers formed thereon, and having the surface to be polished. The polishing method uses a retainer ring made of a ceramic material containing AlTiC.Type: GrantFiled: March 31, 2008Date of Patent: January 11, 2011Assignee: TDK CorporationInventors: Hiroki Aritomo, Tetsuji Hori, Akira Miyasaka, Youji Hirao
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Patent number: 7815317Abstract: A projector includes an image acquiring unit that acquires an image including the projection image captured by the image-capturing device during image projection, an image region separating unit that separates a projection image region and a background image region from the acquired image, a background image time-lapse change storage unit that stores a time-lapse change of the background image acquired by a background time-lapse change acquiring unit, a projection image time-lapse change storage unit that stores a time-lapse change of the projection image acquired by a projection image time-lapse change acquiring unit, an tendency-of-use judging unit that judges a tendency of use of the projector on the basis of the stored time-lapse change of the background image and the stored time-lapse change of the projection image, and a light quantity adjusting unit that adjusts a light quantity of the light source on the basis of the judgment result.Type: GrantFiled: March 16, 2007Date of Patent: October 19, 2010Assignee: Seiko Epson CorporationInventor: Akira Miyasaka
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Patent number: 7724653Abstract: A transmission device is connected to a layer 2 switch through a transmission path at one side, and to a relay transmission path at the other side. The transmission path includes a transmission path of a active system and a transmission path of a stand-by system. When failure occurs in the transmission path of the active system, the transmission device forcibly shuts down the transmission path of the active system upon detection of link down, to stop packet transmission, and causes the layer 2 switch to perform MAC address flush. The transmission device then switches the transmission path of the stand-by system to the active system, and transmits packets through the transmission path that has become the active system as a result of switching. The layer 2 switch performs MAC address learning to set a port, thereby maintaining communication even after occurrence of the failure.Type: GrantFiled: September 28, 2007Date of Patent: May 25, 2010Assignee: Fujitsu LimitedInventors: Youichi Konuma, Koichi Saiki, Junichi Shimada, Akira Miyasaka
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Publication number: 20090247060Abstract: Disclosed is a polishing method for polishing a surface of a structure for magnetic-head manufacture by CMP in the process of manufacturing a magnetic head using a ceramic substrate made of a ceramic material containing AlTiC, the structure including the ceramic substrate and one or more layers formed thereon, and having the surface to be polished. The polishing method uses a retainer ring made of a ceramic material containing AlTiC.Type: ApplicationFiled: March 31, 2008Publication date: October 1, 2009Applicants: TDK CORPORATION, MARUSHIN-INDUSTRY CO., LTD.Inventors: Hiroki Aritomo, Tetsuji Hori, Akira Miyasaka, Youji Hirao
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Patent number: 7364304Abstract: To automatically adjust the quality of a projection image commensurate with the performance in-time deterioration and aging of projector component parts in an image projection system, each projector detects an integrated service time of its own light-source lamp and a service time and temperature of a liquid-crystal panel, and sends a detection result thereof to a control unit in compliance with a request from the control unit. These parameter values are parameter values having an effect upon the quality of a projection image and varying with time. The control unit copes with the projectors depending upon the detection result received from the projectors, to set predetermined control data for use in image-quality adjustment and send the control data respectively to the projectors. Each projector controls the driving to its light-source lamp and liquid-crystal panel, depending upon the control data received from the control unit.Type: GrantFiled: March 23, 2005Date of Patent: April 29, 2008Assignee: Seiko Epson CorporationInventors: Tomohiro Nomizo, Akira Miyasaka
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Publication number: 20080089226Abstract: A transmission device is connected to a layer 2 switch through a transmission path at one side, and to a relay transmission path at the other side. The transmission path includes a transmission path of a active system and a transmission path of a stand-by system. When failure occurs in the transmission path of the active system, the transmission device forcibly shuts down the transmission path of the active system upon detection of link down, to stop packet transmission, and causes the layer 2 switch to perform MAC address flush. The transmission device then switches the transmission path of the stand-by system to the active system, and transmits packets through the transmission path that has become the active system as a result of switching. The layer 2 switch performs MAC address learning to set a port, thereby maintaining communication even after occurrence of the failure.Type: ApplicationFiled: September 28, 2007Publication date: April 17, 2008Inventors: Youichi Konuma, Koichi Saiki, Junichi Shimada, Akira Miyasaka