Patents by Inventor Naoki Yutani
Naoki Yutani 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: 8178972Abstract: A semiconductor device is obtained, in which excellent characteristics are achieved, the reliability is improved, and an SiC wafer can also be used for the fabrication. A plurality of Schottky-barrier-diode units 10 is formed on an SiC chip 9, and each of the units 10 has an external output electrode 4 independently of each other. Bumps 11 (the diameter is from several tens to several hundreds of ?m) are formed only on the external output electrodes 4 of non-defective units among the units 10 formed on the SiC chip 9, meanwhile bumps are not formed on the external output electrodes 4 of defective units in which the withstand voltage is too low, or the leakage current is too much.Type: GrantFiled: November 17, 2010Date of Patent: May 15, 2012Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Naoki Yutani
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Publication number: 20120028453Abstract: An object is to provide a method for manufacturing a silicon carbide semiconductor device in which a time required for removing a sacrificial oxide film can be shortened and damage to a surface of the silicon carbide layer can be reduced. The method for manufacturing a silicon carbide semiconductor device includes: (a) performing ion implantation to a silicon carbide layer; (b) performing activation annealing to the ion-implanted silicon carbide layer 2; (c) removing a surface layer of the silicon carbide layer 2, to which the activation annealing has been performed, by dry etching; (d) forming a sacrificial oxide film on a surface layer of the silicon carbide layer, to which the dry etching has been performed, by performing sacrificial oxidation thereto; and (e) removing the sacrificial oxide film by wet etching.Type: ApplicationFiled: September 1, 2009Publication date: February 2, 2012Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Yoshinori Matsuno, Kenichi Ohtsuka, Naoki Yutani, Kenichi Kuroda, Hiroshi Watanabe, Shozo Shikama
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Publication number: 20110284874Abstract: In a cell region of a first major surface of a semiconductor substrate of a first conductivity type, a first well of a second conductivity type is in an upper surface. A diffusion region of a first conductivity type is in the upper surface in the first well. A first gate insulating film is on the first well, and a first gate electrode on the first gate insulating film. A second well of a second conductivity type is in the upper surface of the first major surface on a peripheral portion of the cell region. A second gate insulating film is on the second well, and a thick field oxide film is on the peripheral side than the second gate insulating film. A second gate electrode is sequentially on the second gate insulating film and the field oxide film and electrically connected to the first gate electrode. A first electrode is connected to the first, second well and the diffusion region. A second electrode is connected on a second major surface of the semiconductor substrate.Type: ApplicationFiled: April 30, 2009Publication date: November 24, 2011Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Naruhisa Miura, Shuhei Nakata, Kenichi Ohtsuka, Shoyu Watanabe, Naoki Yutani
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Publication number: 20110057311Abstract: A semiconductor device is obtained, in which excellent characteristics are achieved, the reliability is improved, and an SiC wafer can also be used for the fabrication. A plurality of Schottky-barrier-diode units 10 is formed on an SiC chip 9, and each of the units 10 has an external output electrode 4 independently of each other. Bumps 11 (the diameter is from several tens to several hundreds of ?m) are formed only on the external output electrodes 4 of non-defective units among the units 10 formed on the SiC chip 9, meanwhile bumps are not formed on the external output electrodes 4 of defective units in which the withstand voltage is too low, or the leakage current is too much.Type: ApplicationFiled: November 17, 2010Publication date: March 10, 2011Applicant: MITSUBISHI DENKI KABUSHIKI KAISHAInventor: Naoki YUTANI
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Patent number: 7880763Abstract: A semiconductor device is obtained, in which excellent characteristics are achieved, the reliability is improved, and an SiC wafer can also be used for the fabrication. A plurality of Schottky-barrier-diode units 10 is formed on an SiC chip 9, and each of the units 10 has an external output electrode 4 independently of each other. Bumps 11 (the diameter is from several tens to several hundreds of ?m) are formed only on the external output electrodes 4 of non-defective units among the units 10 formed on the SiC chip 9, meanwhile bumps are not formed on the external output electrodes 4 of defective units in which the withstand voltage is too low, or the leakage current is too much.Type: GrantFiled: August 29, 2008Date of Patent: February 1, 2011Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Naoki Yutani
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Publication number: 20110001209Abstract: In a termination structure in which a JTE layer is provided, a level or defect existing at an interface between a semiconductor layer and an insulating film, or a minute amount of adventitious impurities that infiltrate into the semiconductor interface from the insulating film or from an outside through the insulating film becomes a source or a breakdown point of a leakage current, which deteriorates a breakdown voltage.Type: ApplicationFiled: March 12, 2009Publication date: January 6, 2011Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Hiroshi Watanabe, Naoki Yutani, Kenichi Ohtsuka, Kenichi Kuroda, Masayuki Imaizumi, Yoshinori Matsuno
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Publication number: 20090098719Abstract: An object of the invention is to provide a method for manufacturing a silicon carbide semiconductor device having constant characteristics with reduced variations in forward characteristics. The method for manufacturing the silicon carbide semiconductor device according to the invention includes the steps of: (a) preparing a silicon carbide substrate; (b) forming an epitaxial layer on a first main surface of the silicon carbide substrate; (c) forming a protective film on the epitaxial layer; (d) forming a first metal layer on a second main surface of the silicon carbide substrate; (e) applying heat treatment to the silicon carbide substrate at a predetermined temperature to form an ohmic junction between the first metal layer and the second main surface of the silicon carbide substrate; (f) removing the protective film; (g) forming a second metal layer on the epitaxial layer; and (h) applying heat treatment to the silicon carbide substrate at a temperature from 400° C. to 600° C.Type: ApplicationFiled: August 8, 2008Publication date: April 16, 2009Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Yoshinori MATSUNO, Kenichi Ohtsuka, Kenichi Kuroda, Shozo Shikama, Naoki Yutani
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Publication number: 20090004761Abstract: A semiconductor device is obtained, in which excellent characteristics are achieved, the reliability is improved, and an SiC wafer can also be used for the fabrication. A plurality of Schottky-barrier-diode units 10 is formed on an SiC chip 9, and each of the units 10 has an external output electrode 4 independently of each other. Bumps 11 (the diameter is from several tens to several hundreds of ?m) are formed only on the external output electrodes 4 of non-defective units among the units 10 formed on the SiC chip 9, meanwhile bumps are not formed on the external output electrodes 4 of defective units in which the withstand voltage is too low, or the leakage current is too much.Type: ApplicationFiled: August 29, 2008Publication date: January 1, 2009Applicant: MITSUBISHI DENKI KABUSHIKI KAISHAInventor: Naoki YUTANI
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Publication number: 20060131745Abstract: A semiconductor device is obtained, in which excellent characteristics are achieved, the reliability is improved, and an SiC wafer can also be used for the fabrication. A plurality of Schottky-barrier-diode units 10 is formed on an SiC chip 9, and each of the units 10 has an external output electrode 4 independently of each other. Bumps 11 (the diameter is from several tens to several hundreds of ?m) are formed only on the external output electrodes 4 of non-defective units among the units 10 formed on the SiC chip 9, meanwhile bumps are not formed on the external output electrodes 4 of defective units in which the withstand voltage is too low, or the leakage current is too much.Type: ApplicationFiled: November 21, 2005Publication date: June 22, 2006Applicant: MITSUBISHI DENKI KABUSHIKI KAISHAInventor: Naoki Yutani
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Patent number: 6619130Abstract: A pressure sensor includes a first diaphragm having a first surface receiving pressure, a first thermal detection section located opposite a central section of the first diaphragm, and a second thermal detection section having little displacement by pressure, and located opposite the first diaphragm The pressure sensor amplifies and outputs a difference between the first thermal detection section for pressure measurement and the second thermal detection section for reference output. Since the diaphragm to which the second thermal detection section is opposed is equal in thickness to the diaphragm to which the first thermal detection section is opposed, pressure can be accurately measured relative to a sudden change in atmospheric temperature.Type: GrantFiled: June 5, 2002Date of Patent: September 16, 2003Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Naoki Yutani, Hiroshi Ohji, Kazuhiko Tsutsumi
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Patent number: 6591683Abstract: A pressure sensor includes a diaphragm having a first surface receiving pressure, and a first thermal detection section opposed to a central section of the diaphragm through a spacer and having a thermo-sensitive resistance section, and a second thermal detection section opposed to an end section of the diaphragm and having a thermo-sensitive resistance section, wherein the first thermo-sensitive resistance section and second thermo-sensitive resistance section are connected to independent, adjustable constant-current sources, respectively, and are connected to a differential amplifier which amplifies a difference between (i) a voltage of the first thermal detection section, which detects a displacement quantity of the diaphragm due to pressure change as a displacement quantity of a thermal equilibrium state by the thermal detection section, and (ii) a voltage of the second thermal detection section, which does not change according to pressure. The sensor can measure pressure with high accuracy.Type: GrantFiled: August 9, 2002Date of Patent: July 15, 2003Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Naoki Yutani, Hiroshi Ohji, Kazuhiko Tsutsumi
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Patent number: 6393919Abstract: A pressure sensor of the present invention comprises a diaphragm 6 having a first surface which receives pressure and a thermal detecting portion 3 with a heat sensitive portion disposed as to oppose the diaphragm through a spacer, wherein displacement values of the diaphragm owing to variations in pressure are detected at the thermal detecting portion as variation values of thermal equilibrium state. With this arrangement, a surface of the diaphragm which directly receives pressure from measuring fluid does not need to undergo film forming or photolithographic processes whereby main portions of thermal pressure detecting elements might be formed onto a silicon substrate by large quantities in a lump sum through simple manufacturing processes so that it is possible to improve accuracy and reliability of the thermal pressure detecting elements and to obtain a pressure sensor of low cost.Type: GrantFiled: August 24, 2000Date of Patent: May 28, 2002Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hiroshi Ohji, Kazuhiko Tsutsumi, Yuichi Sakai, Naoki Yutani
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Patent number: 6207067Abstract: A method for fabricating an oxide superconducting device includes the steps of: forming a V-shaped groove on a substrate by a converging ion beam and forming a barrier with reduced superconductivity on the oxide superconducting thin-film on the groove to form a Josephson Junction, wherein the irradiation ion amount of the converging ion beam is varied according to the position of the beam within the groove in such a manner that an inclination angle of the inclined portion of the substrate is fixed. An oxide superconducting device (a Josephson Junction device) having a high degree of flexibility in arrangement and with high reproducibility, and having a high degree of uniformity is provided.Type: GrantFiled: September 29, 1998Date of Patent: March 27, 2001Assignees: Mitsubishi Denki Kabushiki Kaisha, International Superconductivity Technology CenterInventors: Naoki Yutani, Katsumi Suzuki, Youichi Enomoto, Jian-Guo Wen
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Patent number: 5444484Abstract: A solid-state imaging device includes a two-dimensional array of photodetectors, a TG scanner outputting a selection pulse for reading out signal charges stored in the photodetectors, an interlace circuit receiving the selection pulse from said TG scanner and converting the selection pulse to a field storage mode operation pulse or to a frame storage mode operation pulse, and an interlace switching circuit receiving the pulse from said interlace circuit and switching the array of photodetectors between the field storage mode and the frame storage mode. The switching between the frame storage mode and the field storage mode is controlled by an external control signal. Therefore, the solid-state imaging device can select an optimum interlace system according to background conditions and the brightness and size of objects imaged.Type: GrantFiled: November 23, 1992Date of Patent: August 22, 1995Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Naoki Yutani, Masafumi Kimata
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Patent number: 5060038Abstract: An image sensor using a charge sweep device as a vertical transfer device (3) and comprising a plurality of pixels (10) each of which is formed of a single photo-electro transforming element (1) and a single transfer gate (4) for transferring a signal charge from the photo-electro transforming element into the charge sweep device (3), wherein the width of the transfer gate (4) is equal to or larger than that of the photo-electro transforming element in the direction of charge transfer in the charge sweep device (3).Type: GrantFiled: November 30, 1989Date of Patent: October 22, 1991Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Masafumi Kimata, Naoki Yutani, Masahiko Denda
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Patent number: 5040038Abstract: A solid-state image sensor comprises photoelectric converting devices (22) formed on a p type semiconductor substrate (1), transfer gates (26) for reading signal charges therefrom, scanning lines (21) for selecting the transfer gates (26), and transfer electrodes (11) of the first layer and transfer electrodes (12) of the second layer alternately disposed for transferring in the vertical direction the read signal charges. All the electrodes of the transfer gates (26) are formed integrally with the transfer electrodes (12) of the second layer, with the result that all the electrodes of the transfer gates (26) are common to the transfer electrodes of the same layer (the second layer). Although the potential wall (340) is formed in the transfer channel (3) beneath the transfer electrode (12) connected to the transfer gate (26), the same is insulated from adjacent the transfer electrode (11) on the charge transfer direction side.Type: GrantFiled: October 24, 1988Date of Patent: August 13, 1991Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Naoki Yutani, Sotoju Asai, Shiro Hine, Satoshi Hirose, Hidekazu Yamamoto, Masashi Ueno