Patents by Inventor Tsuyoshi Ishikawa

Tsuyoshi Ishikawa 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).

  • Publication number: 20140252465
    Abstract: A semiconductor device has a semiconductor substrate including a body region, a drift region, a trench that extends from a surface of the semiconductor substrate into the drift region through the body region, and a source region located adjacent to the trench in a range exposed to the surface of the semiconductor substrate, the source region being isolated from the drift region by the body region. A specific layer is disposed on a bottom of the trench, and it has a characteristic of forming a depletion layer at a junction between the specific layer and the drift region. An insulating layer covers an upper surface of the specific layer and a sidewall of the trench. A conductive portion is formed on a part of the side wall of the trench. The conductive portion is joined to the specific layer, and reaches the surface of the semiconductor substrate.
    Type: Application
    Filed: October 17, 2012
    Publication date: September 11, 2014
    Applicants: DENSO CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Hidefumi Takaya, Hideo Matsuki, Naohiro Suzuki, Tsuyoshi Ishikawa, Narumasa Soejima, Yukihiko Watanabe
  • Publication number: 20140175459
    Abstract: A SiC semiconductor device includes: a semiconductor switching element having: a substrate, a drift layer and a base region stacked in this order; a source region and a contact region in the base region; a trench extending from a surface of the source region to penetrate the base region; a gate electrode on a gate insulating film in the trench; a source electrode electrically coupled with the source region and the base region; a drain electrode on a back side of the substrate; and multiple deep layers in an upper portion of the drift layer deeper than the trench. Each deep layer has upper and lower portions. A width of the upper portion is smaller than the lower portion.
    Type: Application
    Filed: February 6, 2012
    Publication date: June 26, 2014
    Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, DENSO CORPORATION
    Inventors: Kensaku Yamamoto, Masato Noborio, Hideo Matsuki, Hidefumi Takaya, Masahiro Sugimoto, Narumasa Soejima, Tsuyoshi Ishikawa, Yukihiko Watanabe
  • Patent number: 8710586
    Abstract: A SiC semiconductor device includes: a substrate, a drift layer, and a base region stacked in this order; first and second source regions and a contact layer in the base region; a trench penetrating the source and base regions; a gate electrode in the trench; an interlayer insulation film with a contact hole covering the gate electrode; a source electrode coupling with the source region and the contact layer via the contact hole; a drain electrode on the substrate; and a metal silicide film. The high concentration second source region is shallower than the low concentration first source region, and has a part covered with the interlayer insulation film, which includes a low concentration first portion near a surface and a high concentration second portion deeper than the first portion. The metal silicide film on the second part has a thickness larger than the first portion.
    Type: Grant
    Filed: September 12, 2011
    Date of Patent: April 29, 2014
    Assignees: DENSO CORPORATION, Toyota Jidosha Kabushiki Kaisha
    Inventors: Toshimasa Yamamoto, Masahiro Sugimoto, Hidefumi Takaya, Jun Morimoto, Narumasa Soejima, Tsuyoshi Ishikawa, Yukihiko Watanabe
  • Publication number: 20140091165
    Abstract: A media-agitation type pulverizer of the present invention includes: a guide ring installed to radially divide a lower region of a pulverization chamber into an inner section and an annular outer section. A flow of a mixture of a raw material slurry and pulverizing media is formed as a helicoidal flow comprising a secondary flow flowing through a circulation flow path which has an upward flow path and a downward flow path created, respectively, in the outer section and the inner section of the lower region of the pulverization chamber, with respect to the guide ring. A rotational-flow suppressing device is provided within the pulverization chamber and adapted to strengthen the secondary flow of the helicoidal flow, thereby stabilizing the helicoidal flow.
    Type: Application
    Filed: July 23, 2012
    Publication date: April 3, 2014
    Applicant: ASHIZAWA FINETECH LTD.
    Inventors: Tsuyoshi Ishikawa, Shogo Iwasawa, Takahiro Tamura
  • Patent number: 8618555
    Abstract: The silicon carbide semiconductor device includes a substrate, a drift layer, a base region, a source region, a trench, a gate insulating layer, a gate electrode, a source electrode, a drain electrode, and a deep layer. The deep layer is disposed under the base region and is located to a depth deeper than the trench. The deep layer is divided into a plurality of portions in a direction that crosses a longitudinal direction of the trench. The portions include a group of portions disposed at positions corresponding to the trench and arranged at equal intervals in the longitudinal direction of the trench. The group of portions surrounds corners of a bottom of the trench.
    Type: Grant
    Filed: May 27, 2011
    Date of Patent: December 31, 2013
    Assignees: DENSO CORPORATION, Toyota Jidosha Kabushiki Kaisha
    Inventors: Naohiro Suzuki, Hideo Matsuki, Masahiro Sugimoto, Hidefumi Takaya, Jun Morimoto, Tsuyoshi Ishikawa, Narumasa Soejima, Yukihiko Watanabe
  • Patent number: 8609055
    Abstract: A method of producing fluoroapatite by using a calcium-based compound containing calcium, hydrogen fluoride and phosphoric acid is provided. The method can be produced fluoroapatite having improved acid resistance by reducing an amount of an impurity derived from a raw material to a low or very low level, and ability capable of separating a large amount of a protein due to a large specific surface area thereof. Further, fluoroapatite having high acid resistance and a large specific surface area is also provided. Furthermore, an adsorption apparatus using such fluoroapatite is also provided.
    Type: Grant
    Filed: August 27, 2008
    Date of Patent: December 17, 2013
    Assignee: Hoya Corporation
    Inventors: Tsuyoshi Ishikawa, Yoshiyuki Ogawara, Tomohiko Yoshitake, Yukiki Murakami
  • Publication number: 20130330896
    Abstract: A manufacturing method of a silicon carbide semiconductor device includes: forming a drift layer on a silicon carbide substrate; forming a base layer on or in a surface portion of the drift layer; forming a source region in a surface portion of the base layer; forming a trench to penetrate the base layer and to reach the drift layer; forming a gate electrode on a gate insulation film in the trench; forming a source electrode electrically connected to the source region and the base layer; and forming a drain electrode on a back surface of the substrate. The forming of the trench includes: flattening a substrate surface; and etching to form the trench after flattening.
    Type: Application
    Filed: September 4, 2012
    Publication date: December 12, 2013
    Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, DENSO CORPORATION
    Inventors: Shinichiro Miyahara, Toshimasa Yamamoto, Hidefumi Takaya, Masahiro Sugimoto, Yukihiko Watanabe, Narumasa Soejima, Tsuyoshi Ishikawa
  • Patent number: 8575689
    Abstract: An SiC semiconductor device includes a substrate, a drift layer, a base region, a source region, a trench, a gate oxide film, a gate electrode, a source electrode and a drain electrode. The substrate has a Si-face as a main surface. The source region has the Si-face. The trench is provided from a surface of the source region to a portion deeper than the base region and extends longitudinally in one direction and has a Si-face bottom. The trench has an inverse tapered shape, which has a smaller width at an entrance portion than at a bottom, at least at a portion that is in contact with the base region.
    Type: Grant
    Filed: December 20, 2011
    Date of Patent: November 5, 2013
    Assignees: DENSO CORPORATION, Toyota Jidosha Kabushiki Kaisha
    Inventors: Tomohiro Mimura, Shinichiro Miyahara, Hidefumi Takaya, Masahiro Sugimoto, Narumasa Soejima, Tsuyoshi Ishikawa, Yukihiko Watanabe
  • Patent number: 8525223
    Abstract: A SiC semiconductor device includes: a SiC substrate including a first or second conductive type layer and a first conductive type drift layer and including a principal surface having an offset direction; a trench disposed on the drift layer and having a longitudinal direction; and a gate electrode disposed in the trench via a gate insulation film. A sidewall of the trench provides a channel formation surface. The vertical semiconductor device flows current along with the channel formation surface of the trench according to a gate voltage applied to the gate electrode. The offset direction of the SiC substrate is perpendicular to the longitudinal direction of the trench.
    Type: Grant
    Filed: April 19, 2012
    Date of Patent: September 3, 2013
    Assignees: DENSO CORPORATION, Toyota Jidosha Kabushiki Kaisha
    Inventors: Hiroki Watanabe, Shinichiro Miyahara, Masahiro Sugimoto, Hidefumi Takaya, Yukihiko Watanabe, Narumasa Soejima, Tsuyoshi Ishikawa
  • Patent number: 8518809
    Abstract: A manufacturing method of an SiC single crystal includes preparing an SiC substrate, implanting ions into a surface portion of the SiC substrate to form an ion implantation layer, activating the ions implanted into the surface portion of the SiC substrate by annealing, chemically etching the surface portion of the SiC substrate to form an etch pit that is caused by a threading screw dislocation included in the SiC substrate and performing an epitaxial growth of SiC to form an SiC growth layer on a surface of the SiC substrate including an inner wall of the etch pit in such a manner that portions of the SiC growth layer grown on the inner wall of the etch pit join with each other.
    Type: Grant
    Filed: December 1, 2011
    Date of Patent: August 27, 2013
    Assignee: DENSO CORPORATION
    Inventors: Hiroki Watanabe, Yasuo Kitou, Yasushi Furukawa, Kensaku Yamamoto, Hidefumi Takaya, Masahiro Sugimoto, Yukihiko Watanabe, Narumasa Soejima, Tsuyoshi Ishikawa
  • Patent number: 8492867
    Abstract: A semiconductor device includes a semiconductor substrate and an electric field terminal part. The semiconductor substrate includes a substrate, a drift layer disposed on a surface of the substrate, and a base layer disposed on a surface of the drift layer. The semiconductor substrate is divided into a cell region in which a semiconductor element is disposed and a peripheral region that surrounds the cell region. The base region has a bottom face located on a same plane throughout the cell region and the peripheral region and provides an electric field relaxing layer located in the peripheral region. The electric field terminal part surrounds the cell region and a portion of the electric field relaxing layer and penetrates the electric field relaxing layer from a surface of the electric field relaxing layer to the drift layer.
    Type: Grant
    Filed: June 20, 2011
    Date of Patent: July 23, 2013
    Assignees: DENSO CORPORATION, Toyota Jidosha Kabushiki Kaisha
    Inventors: Kensaku Yamamoto, Naohiro Suzuki, Hidefumi Takaya, Masahiro Sugimoto, Jun Morimoto, Narumasa Soejima, Tsuyoshi Ishikawa, Yukihiko Watanabe
  • Patent number: 8470672
    Abstract: A method of manufacturing a semiconductor device includes forming a drift layer on a substrate; forming a base layer on the drift layer; forming a trench to penetrate the base layer and to reach the drift layer; rounding off a part of a shoulder corner and a part of a bottom corner of the trench; covering an inner wall of the trench with an organic film; implanting an impurity to a surface portion of the base layer; forming a source region by activating the implanted impurity; and removing the organic film after the source region is formed, in which the substrate, the drift layer, the base layer and the source region are made of silicon carbide, and the implanting and the activating of the impurity are performed under a condition that the trench is covered with the organic film.
    Type: Grant
    Filed: August 30, 2011
    Date of Patent: June 25, 2013
    Assignees: DENSO CORPORATION, Toyota Jidosha Kabushiki Kaisha
    Inventors: Takeshi Endo, Shinichiro Miyahara, Tomoo Morino, Masaki Konishi, Hirokazu Fujiwara, Jun Morimoto, Tsuyoshi Ishikawa, Takashi Katsuno, Yukihiko Watanabe
  • Patent number: 8436365
    Abstract: A SiC semiconductor device having a Schottky barrier diode includes: a substrate made of SiC and having a first conductive type, wherein the substrate includes a main surface and a rear surface; a drift layer made of SiC and having the first conductive type, wherein the drift layer is disposed on the main surface of the substrate and has an impurity concentration lower than the substrate; a Schottky electrode disposed on the drift layer and has a Schottky contact with a surface of the drift layer; and an ohmic electrode disposed on the rear surface of the substrate. The Schottky electrode directly contacts the drift layer in such a manner that a lattice of the Schottky electrode is matched with a lattice of the drift layer.
    Type: Grant
    Filed: February 21, 2011
    Date of Patent: May 7, 2013
    Assignees: DENSO CORPORATION, Toyota Jidosha Kabushiki Kaisha
    Inventors: Takeo Yamamoto, Takeshi Endo, Jun Morimoto, Hirokazu Fujiwara, Yukihiko Watanabe, Takashi Katsuno, Tsuyoshi Ishikawa
  • Publication number: 20130075760
    Abstract: The present application relates to technology for improving a withstand voltage of a semiconductor device. The semiconductor device includes a termination area that surrounds a cell area. The cell area is provided with a plurality of main trenches. The termination area is provided with one or more termination trenches surrounding the cell area. A termination trench is disposed at an innermost circumference of one or more termination trenches. A body region is disposed on a surface of a drift region. Each main trench reaches the drift region. A gate electrode is provided within each main trench. The termination trench reaches the drift region. Sidewalls and a bottom surface of the termination trench are covered with a insulating layer. A surface of the insulating layer covering the bottom surface of the termination trench is covered with a buried electrode. A gate potential is applied to the buried electrode.
    Type: Application
    Filed: June 2, 2011
    Publication date: March 28, 2013
    Applicants: DENSO CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Hidefumi Takaya, Hideo Matsuki, Naohiro Suzuki, Tsuyoshi Ishikawa
  • Publication number: 20130014013
    Abstract: There is provided an information processing apparatus including a page switching unit for switching a display screen from a first Web page screen displayed on a display unit to a second Web page screen, and a switching information notification unit for notifying a page switching information on a notification screen before the second Web page screen is displayed while switching between the pages by the page switching unit, the page switching information is based on information included in at least the second Web page of the first and second Web pages, and the notification screen is a different screen from the first Web page.
    Type: Application
    Filed: May 11, 2012
    Publication date: January 10, 2013
    Applicant: Sony Corporation
    Inventors: Yuya AOKI, Tsuyoshi ISHIKAWA, Mitsuru NISHIBE, Takahiro OKAYAMA, Shunichi KASAHARA
  • Publication number: 20130001592
    Abstract: In a silicon carbide semiconductor device, a plurality of trenches has a longitudinal direction in one direction and is arranged in a stripe pattern. Each of the trenches has first and second sidewalls extending in the longitudinal direction. The first sidewall is at a first acute angle to one of a (11-20) plane and a (1-100) plane, the second sidewall is at a second acute angle to the one of the (11-20) plane and the (1-100) plane, and the first acute angle is smaller than the second acute angle. A first conductivity type region is in contact with only the first sidewall in the first and second sidewalls of each of the trenches, and a current path is formed on only the first sidewall in the first and second sidewalls.
    Type: Application
    Filed: June 25, 2012
    Publication date: January 3, 2013
    Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, DENSO CORPORATION
    Inventors: Shinichiro Miyahara, Masahiro Sugimoto, Hidefumi Takaya, Yukihiko Watanabe, Narumasa Soejima, Tsuyoshi Ishikawa
  • Publication number: 20120319136
    Abstract: A SiC device includes an inversion type MOSFET having: a substrate, a drift layer, and a base region stacked in this order; source and contact regions in upper portions of the base region; a trench penetrating the source and base regions; a gate electrode on a gate insulating film in the trench; a source electrode coupled with the source and base region; a drain electrode on a back of the substrate; and multiple deep layers in an upper portion of the drift layer deeper than the trench. Each deep layer has an impurity concentration distribution in a depth direction, and an inversion layer is provided in a portion of the deep layer on the side of the trench under application of the gate voltage.
    Type: Application
    Filed: February 6, 2012
    Publication date: December 20, 2012
    Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, DENSO CORPORATION
    Inventors: Masato Noborio, Kensaku Yamamoto, Hideo Matsuki, Hidefumi Takaya, Masahiro Sugimoto, Narumasa Soejima, Tsuyoshi Ishikawa, Yukihiko Watanabe
  • Publication number: 20120304268
    Abstract: An information processing apparatus includes a communication unit for communicating with another information processing apparatus and a determination unit for determining whether or not to authenticate the other information processing apparatus on the basis of an operation pattern reported to a user and an analysis result of the user's operation corresponding to the operation pattern.
    Type: Application
    Filed: May 17, 2012
    Publication date: November 29, 2012
    Inventors: Akihiro KOMORI, Qihong WANG, Tomohisa TANAKA, Tsuyoshi ISHIKAWA
  • Publication number: 20120297343
    Abstract: An electronic apparatus includes a display unit, a sensor, and a controller. The display unit includes a screen. The sensor is configured to detect a user operation with respect to the screen and output a signal corresponding to the user operation. The controller is configured to cause a data icon and an access authority editing icon for editing an access authority of data related to the data icon to be displayed on the screen, judge a user operation with respect to the access authority editing icon based on the signal from the sensor, and change a state of the access authority of the data related to the data icon according to the user operation.
    Type: Application
    Filed: May 8, 2012
    Publication date: November 22, 2012
    Inventors: Tsuyoshi ISHIKAWA, Tomohisa TANAKA, Qihong WANG, Akihiro KOMORI
  • Publication number: 20120297329
    Abstract: An electronic apparatus includes a display unit, a sensor, and a controller. The display unit includes a screen. The sensor is configured to detect a user operation with respect to the screen and output a signal corresponding to the user operation. The controller is configured to cause a data icon to be displayed on the screen, judge a drag operation with respect to the data icon based on the signal from the sensor, judge, based on the signal from the sensor, a user operation different from the drag operation for one of copying and moving data related to the data icon based on the drag operation, and execute processing for one of copying and moving the data according to the user operation.
    Type: Application
    Filed: May 11, 2012
    Publication date: November 22, 2012
    Inventors: Tomohisa Tanaka, Tsuyoshi Ishikawa, Qihong Wang, Akihiro Komori