Patents by Inventor Yuuichi Takeuchi

Yuuichi Takeuchi 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).

  • Patent number: 8604540
    Abstract: A wide band gap semiconductor device having a JFET, a MESFET, or a MOSFET mainly includes a semiconductor substrate, a first conductivity type semiconductor layer, and a first conductivity type channel layer. The semiconductor layer is formed on a main surface of the substrate. A recess is formed in the semiconductor layer in such a manner that the semiconductor layer is divided into a source region and a drain region. The recess has a bottom defined by the main surface of the substrate and a side wall defined by the semiconductor layer. The channel layer has an impurity concentration lower than an impurity concentration of the semiconductor layer. The channel layer is formed on the bottom and the side wall of the recess by epitaxial growth.
    Type: Grant
    Filed: November 30, 2010
    Date of Patent: December 10, 2013
    Assignee: DENSO CORPORATION
    Inventors: Rajesh Kumar Malhan, Naohiro Sugiyama, Yuuichi Takeuchi
  • Patent number: 8575648
    Abstract: A silicon carbide semiconductor device having a JFET or a MOSFET includes a semiconductor substrate and a trench. The semiconductor substrate has a silicon carbide substrate, a drift layer on the silicon carbide substrate, a first gate region on the drift layer, and a source region on the first gate region. The trench has a strip shape with a longitudinal direction and reaches the drift layer by penetrating the source region and the first gate region. The trench is filled with a channel layer and a second gate region on the channel layer. The source region is not located at an end portion of the trench in the longitudinal direction.
    Type: Grant
    Filed: December 22, 2010
    Date of Patent: November 5, 2013
    Assignee: DENSO CORPORATION
    Inventors: Yuuichi Takeuchi, Rajesh Kumar Malhan, Naohiro Sugiyama
  • Publication number: 20130105889
    Abstract: A method for manufacturing a switching device, which includes a trench type gate electrode and first to fourth semiconductor regions, is provided. The first semiconductor region is in contact with a gate insulating film and is of n-type. The second semiconductor region is in contact with the gate insulating film, and is of p-type. The third semiconductor region is in contact with the gate insulating film, and is of n-type. The fourth semiconductor region is a p-type semiconductor region which is positioned in a range deeper than the second semiconductor region and consecutive with the second semiconductor region, and which faces the gate insulating film via the third semiconductor region. The manufacturing method includes forming the second semiconductor region in which aluminum is doped, and implanting boron into a range in which the fourth semiconductor region is to be formed in the semiconductor substrate.
    Type: Application
    Filed: September 14, 2012
    Publication date: May 2, 2013
    Applicants: DENSO CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Hirokazu FUJIWARA, Hisashi ISHIMABUSHI, Yukihiko WATANABE, Narumasa SOEJIMA, Toshimasa YAMAMOTO, Yuuichi TAKEUCHI
  • Patent number: 8274086
    Abstract: A wide band gap semiconductor device has a transistor cell region, a diode forming region, an electric field relaxation region located between the transistor cell region and the diode forming region, and an outer peripheral region surrounding the transistor cell region and the diode forming region. In the transistor cell region, a junction field effect transistor is disposed. In the diode forming region, a diode is disposed. In the electric field relaxation region, an isolating part is provided. The isolating part includes a trench dividing the transistor cell region and the diode forming region, a first conductivity-type layer disposed on an inner wall of the trench, and a second conductivity-type layer disposed on a surface of the first conductivity-type layer so as to fill the trench. The first conductivity-type layer and the second conductivity-type layer provide a PN junction.
    Type: Grant
    Filed: July 28, 2009
    Date of Patent: September 25, 2012
    Assignees: DENSO CORPORATION, University of Cambridge
    Inventors: Rajesh Kumar Malhan, Yuuichi Takeuchi, Jeremy Rashid
  • Patent number: 7989231
    Abstract: In a method of manufacturing a silicon carbide semiconductor device, a trench and a thickness measurement section are formed in a surface of a semiconductor substrate made of silicon carbide. The thickness measurement section includes a plurality of grooves and a protruding portion provided between the grooves so as to have a predetermined width. When an epitaxial layer made of silicon carbide is grown, a thickness of the epitaxial layer formed on the surface of the semiconductor substrate is measured by calculating a difference in height between a surface of the epitaxial layer formed on a portion of the surface of the semiconductor substrate different from the thickness measurement section and a top surface of the protruding portion. The predetermined width is less than a surface migration amount of atoms during growth of the epitaxial layer.
    Type: Grant
    Filed: March 11, 2010
    Date of Patent: August 2, 2011
    Assignee: DENSO CORPORATION
    Inventors: Atsuya Akiba, Yuuichi Takeuchi
  • Publication number: 20110156054
    Abstract: A silicon carbide semiconductor device having a JFET or a MOSFET includes a semiconductor substrate and a trench. The semiconductor substrate has a silicon carbide substrate, a drift layer on the silicon carbide substrate, a first gate region on the drift layer, and a source region on the first gate region. The trench has a strip shape with a longitudinal direction and reaches the drift layer by penetrating the source region and the first gate region. The trench is filled with a channel layer and a second gate region on the channel layer. The source region is not located at an end portion of the trench in the longitudinal direction.
    Type: Application
    Filed: December 22, 2010
    Publication date: June 30, 2011
    Applicant: DENSO CORPORATION
    Inventors: Yuuichi TAKEUCHI, Rajesh Kumar Malhan, Naohiro Sugiyama
  • Publication number: 20110156052
    Abstract: A semiconductor device having a JFET includes: a substrate made of semi-insulating semiconductor material; a gate region in a surface portion of the substrate; a channel region disposed on and contacting the gate region; a source region and a drain region disposed on both sides of the gate region so as to sandwich the channel region, respectively; a source electrode electrically coupled with the source region; a drain electrode electrically coupled with the drain region; and a gate electrode electrically coupled with the gate region. An impurity concentration of each of the source region and the drain region is higher than an impurity concentration of the channel region.
    Type: Application
    Filed: December 16, 2010
    Publication date: June 30, 2011
    Applicant: DENSO CORPORATION
    Inventors: Rajesh Kumar Malhan, Yuuichi Takeuchi, Naohiro Sugiyama
  • Publication number: 20110133211
    Abstract: A wide band gap semiconductor device having a JFET, a MESFET, or a MOSFET mainly includes a semiconductor substrate, a first conductivity type semiconductor layer, and a first conductivity type channel layer. The semiconductor layer is formed on a main surface of the substrate. A recess is formed in the semiconductor layer in such a manner that the semiconductor layer is divided into a source region and a drain region. The recess has a bottom defined by the main surface of the substrate and a side wall defined by the semiconductor layer. The channel layer has an impurity concentration lower than an impurity concentration of the semiconductor layer. The channel layer is formed on the bottom and the side wall of the recess by epitaxial growth.
    Type: Application
    Filed: November 30, 2010
    Publication date: June 9, 2011
    Applicant: DENSO CORPORATION
    Inventors: Rajesh Kumar MALHAN, Naohiro Sugiyama, Yuuichi Takeuchi
  • Patent number: 7825449
    Abstract: An SiC semiconductor device and a related manufacturing method are disclosed having a structure provided with a p+-type deep layer formed in a depth equal to or greater than that of a trench to cause a depletion layer between at a PN junction between the p+-type deep layer and an n?-type drift layer to extend into the n?-type drift layer in a remarkable length, making it difficult for a high voltage, resulting from an adverse affect arising from a drain voltage, to enter a gate oxide film. This results in a capability of minimizing an electric field concentration in the gate oxide film, i.e., an electric field concentration occurring at the gate oxide film at a bottom wall of the trench.
    Type: Grant
    Filed: October 30, 2008
    Date of Patent: November 2, 2010
    Assignee: DENSO CORPORATION
    Inventors: Naohiro Suzuki, Yuuichi Takeuchi, Takeshi Endo, Eiichi Okuno, Toshimasa Yamamoto
  • Publication number: 20100233832
    Abstract: In a method of manufacturing a silicon carbide semiconductor device, a trench and a thickness measurement section are formed in a surface of a semiconductor substrate made of silicon carbide. The thickness measurement section includes a plurality of grooves and a protruding portion provided between the grooves so as to have a predetermined width. When an epitaxial layer made of silicon carbide is grown, a thickness of the epitaxial layer formed on the surface of the semiconductor substrate is measured by calculating a difference in height between a surface of the epitaxial layer formed on a portion of the surface of the semiconductor substrate different from the thickness measurement section and a top surface of the protruding portion. The predetermined width is less than a surface migration amount of atoms during growth of the epitaxial layer.
    Type: Application
    Filed: March 11, 2010
    Publication date: September 16, 2010
    Applicant: DENSO CORPORATION
    Inventors: Atsuya Akiba, Yuuichi Takeuchi
  • Patent number: 7763543
    Abstract: A method for manufacturing a silicon carbide semiconductor apparatus is disclosed. According to the method, an element structure is formed on a front surface side of a semiconductor substrate. A rear surface of the semiconductor substrate is grinded or polished in a direction parallel to a flat surface of a table. A front surface of the semiconductor substrate is grinded and polished in a direction parallel to the rear surface after the rear surface of the semiconductor substrate is grinded or polished.
    Type: Grant
    Filed: October 28, 2008
    Date of Patent: July 27, 2010
    Assignee: DENSO CORPORATION
    Inventors: Masatake Nagaya, Yuuichi Takeuchi, Katsuhiro Nagata
  • Publication number: 20100025693
    Abstract: A wide band gap semiconductor device has a transistor cell region, a diode forming region, an electric field relaxation region located between the transistor cell region and the diode forming region, and an outer peripheral region surrounding the transistor cell region and the diode forming region. In the transistor cell region, a junction field effect transistor is disposed. In the diode forming region, a diode is disposed. In the electric field relaxation region, an isolating part is provided. The isolating part includes a trench dividing the transistor cell region and the diode forming region, a first conductivity-type layer disposed on an inner wall of the trench, and a second conductivity-type layer disposed on a surface of the first conductivity-type layer so as to fill the trench. The first conductivity-type layer and the second conductivity-type layer provide a PN junction.
    Type: Application
    Filed: July 28, 2009
    Publication date: February 4, 2010
    Applicants: DENSO CORPORATION, University of Cambridge
    Inventors: Rajesh Kumar Malhan, Yuuichi Takeuchi, Jeremy Rashid
  • Publication number: 20090124060
    Abstract: A method for manufacturing a silicon carbide semiconductor apparatus is disclosed. According to the method, an element structure is formed on a front surface side of a semiconductor substrate. A rear surface of the semiconductor substrate is grinded or polished in a direction parallel to a flat surface of a table. A front surface of the semiconductor substrate is grinded and polished in a direction parallel to the rear surface after the rear surface of the semiconductor substrate is grinded or polished.
    Type: Application
    Filed: October 28, 2008
    Publication date: May 14, 2009
    Applicant: DENSO CORPORATION
    Inventors: Masatake Nagaya, Yuuichi Takeuchi, Katsuhiro Nagata
  • Publication number: 20090114969
    Abstract: An SiC semiconductor device and a related manufacturing method are disclosed having a structure provided with a p+-type deep layer formed in a depth equal to or greater than that of a trench to cause a depletion layer between at a PN junction between the p+-type deep layer and an n?-type drift layer to extend into the n?-type drift layer in a remarkable length, making it difficult for a high voltage, resulting from an adverse affect arising from a drain voltage, to enter a gate oxide film. This results in a capability of minimizing an electric field concentration in the gate oxide film, i.e., an electric field concentration occurring at the gate oxide film at a bottom wall of the trench.
    Type: Application
    Filed: October 30, 2008
    Publication date: May 7, 2009
    Applicant: DENSO CORPORATION
    Inventors: Naohiro Suzuki, Yuuichi Takeuchi, Takeshi Endo, Eiichi Okuno, Toshimasa Yamamoto
  • Patent number: 7241694
    Abstract: A method for manufacturing a silicon carbide semiconductor device includes the steps of: forming a trench mask on an upper surface of a semiconductor substrate; forming the trench such that the trench having an aspect ratio equal to or larger than 2 and having a trench slanting angle equal to or larger than 80 degrees is formed; and removing a damage portion in such a manner that the damage portion disposed on an inner surface of the trench formed in the semiconductor substrate in the step of forming the trench is etched and removed in hydrogen atmosphere under decompression pressure at a temperature equal to or higher than 1600° C.
    Type: Grant
    Filed: April 14, 2005
    Date of Patent: July 10, 2007
    Assignee: DENSO Corporation
    Inventors: Yuuichi Takeuchi, Rajesh Kumar Malhan, Hiroyuki Matsunami, Tsunenobu Kimoto
  • Publication number: 20060273323
    Abstract: A semiconductor device includes: a SiC substrate; a silicide layer disposed on the SiC substrate; and a carbide layer disposed on the silicide layer. The silicide layer includes a first metal, and the carbide layer includes a second metal. The first metal is Ni or Ni alloy, and the second metal is Ti, Ta or W. The device provides excellent ohmic contact and high quality surface metallization construction.
    Type: Application
    Filed: June 7, 2006
    Publication date: December 7, 2006
    Applicants: DENSO CORPORATION, The University of Newcastle upon Tyne
    Inventors: Takeo Yamamoto, Malhan Kumar, Yuuichi Takeuchi, Konstantin Vassilevski, Nicholas Wright
  • Patent number: 7078329
    Abstract: An insulating film (2) is formed on a semiconductor substrate (1) formed of silicon carbide. A contact hole (3) is formed in the insulating film (2) to expose a part of the upper surface of the semiconductor substrate (1). Then, nickel (Ni) (4?) is formed above the semiconductor substrate (1). Subsequently, the semiconductor substrate (1) is subjected to a heat treatment, whereby the contact portion of nickel (4?) chemically bonds with the semiconductor substrate (1) to become an alloy layer (4) of silicon carbide and nickel. Nickel (4?) on the insulating film (2) is selectively removed by etching liquid for dissolving the nickel.
    Type: Grant
    Filed: April 15, 2004
    Date of Patent: July 18, 2006
    Assignee: Denso Corporation
    Inventors: Takeshi Endou, Yuuichi Takeuchi
  • Publication number: 20050233539
    Abstract: A method for manufacturing a silicon carbide semiconductor device includes the steps of: forming a trench mask on an upper surface of a semiconductor substrate; forming the trench such that the trench having an aspect ratio equal to or larger than 2 and having a trench slanting angle equal to or larger than 80 degrees is formed; and removing a damage portion in such a manner that the damage portion disposed on an inner surface of the trench formed in the semiconductor substrate in the step of forming the trench is etched and removed in hydrogen atmosphere under decompression pressure at a temperature equal to or higher than 1600° C.
    Type: Application
    Filed: April 14, 2005
    Publication date: October 20, 2005
    Inventors: Yuuichi Takeuchi, Rajesh Malhan, Hiroyuki Matsunami, Tsunenobu Kimoto
  • Patent number: 6853006
    Abstract: A silicon carbide (SiC) substrate is provided with an off-oriented {0001} surface whose off-axis direction is <11-20>. A trench is formed on the SiC to have a stripe structure extending toward a <11-20> direction. An SiC epitaxial layer is formed on an inside surface of the trench.
    Type: Grant
    Filed: July 31, 2003
    Date of Patent: February 8, 2005
    Assignee: Denso Corporation
    Inventors: Mitsuhiro Kataoka, Yuuichi Takeuchi, Masami Naito, Rajesh Kumar, Hiroyuki Matsunami, Tsunenobu Kimoto
  • Patent number: RE43840
    Abstract: A silicon carbide (SiC) substrate is provided with an off-oriented {0001} surface whose off-axis direction is <11-20>. A trench is formed on the SiC to have a stripe structure extending toward a <11-20> direction. An SiC epitaxial layer is formed on an inside surface of the trench.
    Type: Grant
    Filed: October 21, 2010
    Date of Patent: December 4, 2012
    Assignee: DENSO CORPORATION
    Inventors: Mitsuhiro Kataoka, Yuuichi Takeuchi, Masami Naito, Rajesh Kumar, Hiroyuki Matsunami, Tsunenobu Kimoto