Patents by Inventor Tomofusa Shiga

Tomofusa Shiga 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: 20230125063
    Abstract: A semiconductor device includes a semiconductor substrate and a metal film. The metal film is located on the semiconductor substrate. The metal film includes a portion to have a Schottky junction with the semiconductor substrate. The metal film is made of an aluminum alloy in which an element is added to aluminum. The metal film includes a lower metal layer and an upper metal layer. The lower metal layer is located on the semiconductor substrate. The upper metal layer stacks on the lower metal layer. The lower metal layer has a thickness of 2.6 micrometers or less in a stacking direction of the lower metal layer and the upper metal layer.
    Type: Application
    Filed: December 14, 2022
    Publication date: April 20, 2023
    Inventors: Seiji NOMA, Tomofusa SHIGA, Kouji SENDA, Tsuyoshi NISHIWAKI, Yuta FURUMURA, Akitaka SOENO
  • Patent number: 10748988
    Abstract: A semiconductor device has an element part and an outer peripheral part, and a deep layer is formed in the outer peripheral part more deeply than a base layer. When a position of the deep layer closest to the element part is defined as a boundary position, a distance between the boundary position and a position closest to the outer peripheral part in an emitter region is defined as a first distance, and a distance between the boundary position and a position of an end of a collector layer is defined as a second distance, the first distance and the second distance are adjusted such that a carrier density in the outer peripheral part is lowered based on breakdown voltage in the outer peripheral part lowered by the deep layer.
    Type: Grant
    Filed: July 8, 2019
    Date of Patent: August 18, 2020
    Assignee: DENSO CORPORATION
    Inventors: Masanori Miyata, Shigeki Takahashi, Masakiyo Sumitomo, Tomofusa Shiga
  • Publication number: 20190333987
    Abstract: A semiconductor device has an element part and an outer peripheral part, and a deep layer is formed in the outer peripheral part more deeply than a base layer. When a position of the deep layer closest to the element part is defined as a boundary position, a distance between the boundary position and a position closest to the outer peripheral part in an emitter region is defined as a first distance, and a distance between the boundary position and a position of an end of a collector layer is defined as a second distance, the first distance and the second distance are adjusted such that a carrier density in the outer peripheral part is lowered based on breakdown voltage in the outer peripheral part lowered by the deep layer.
    Type: Application
    Filed: July 8, 2019
    Publication date: October 31, 2019
    Inventors: Masanori MIYATA, Shigeki TAKAHASHI, Masakiyo SUMITOMO, Tomofusa SHIGA
  • Patent number: 9847409
    Abstract: A semiconductor device provides an element arrangement region on a semiconductor substrate including: a first semiconductor region on the semiconductor substrate; a second semiconductor region on the first semiconductor region; multiple trench gates penetrating the first semiconductor region and reaching the second semiconductor region; a third semiconductor region contacting the trench gate; a fourth semiconductor region on a rear surface; a first electrode connected to the first and second semiconductor regions; and a second electrode connected to the fourth semiconductor region. Each trench gate includes a main trench gate for generating a channel and a dummy trench gate for improving a withstand voltage of a component. The device further includes: a dummy gate wiring for applying a predetermined voltage to the dummy trench gate; and a dummy pad connected to the dummy gate wiring. The dummy pad and the first electrode are connected by a conductive member.
    Type: Grant
    Filed: July 14, 2015
    Date of Patent: December 19, 2017
    Assignee: DENSO CORPORATION
    Inventors: Tomofusa Shiga, Hiromitsu Tanabe
  • Publication number: 20160020310
    Abstract: A semiconductor device provides an element arrangement region on a semiconductor substrate including: a first semiconductor region on the semiconductor substrate; a second semiconductor region on the first semiconductor region; multiple trench gates penetrating the first semiconductor region and reaching the second semiconductor region; a third semiconductor region contacting the trench gate; a fourth semiconductor region on a rear surface; a first electrode connected to the first and second semiconductor regions; and a second electrode connected to the fourth semiconductor region. Each trench gate includes a main trench gate for generating a channel and a dummy trench gate for improving a withstand voltage of a component. The device further includes: a dummy gate wiring for applying a predetermined voltage to the dummy trench gate; and a dummy pad connected to the dummy gate wiring. The dummy pad and the first electrode are connected by a conductive member.
    Type: Application
    Filed: July 14, 2015
    Publication date: January 21, 2016
    Inventors: Tomofusa SHIGA, Hiromitsu TANABE
  • Patent number: 9136333
    Abstract: A semiconductor device includes: a semiconductor substrate; a vertical type trench gate MOS transistor; a Schottky barrier diode; multiple trenches having a stripe pattern to divide an inner region into first and second separation regions; and a poly silicon film in each trench. The first separation region includes a first conductive type region for providing a source and a second conductive type layer for providing a channel region. The first conductive type region is adjacent to a first trench. The poly silicon film in the first trench is coupled with a gate wiring. A second trench is not adjacent to the first conductive type region. The poly silicon film in the second trench is coupled with a source or gate wiring. The substrate in the second separation region is coupled with the source wiring for providing a Schottky barrier.
    Type: Grant
    Filed: January 18, 2012
    Date of Patent: September 15, 2015
    Assignee: DENSO CORPORATION
    Inventors: Takaaki Aoki, Tomofusa Shiga
  • Publication number: 20150008478
    Abstract: A manufacturing method of a semiconductor device includes applying at least one of a particle ray and a radial ray to a surface of a semiconductor substrate on which a transistor including a gate insulation film and a gate electrode has been formed adjacent to the surface, and annealing the semiconductor substrate for recovering a crystal defect contained in the gate insulation film and the gate electrode, after the applying. Further, the manufacturing method includes pre-annealing for reducing a content of a hydrogen molecule and a water molecule contained in the gate insulation film and the gate electrode to a predetermined concentration, before the applying. In the semiconductor device manufactured by this method, a concentration of thermally stable defect existing in the gate insulation film is reduced to a predetermined concentration.
    Type: Application
    Filed: January 22, 2013
    Publication date: January 8, 2015
    Inventors: Weitao Cheng, Shinji Amano, Yoshifumi Okabe, Tomofusa Shiga
  • Patent number: 8614483
    Abstract: An insulated gate semiconductor device includes a first conductivity-type semiconductor substrate, a second conductivity-type base layer on a first surface side of the substrate, a trench dividing the base layer into channel and floating layers, and a first conductivity-type emitter region that is formed in the channel layer and in contact with the trench. The semiconductor device includes a gate insulation layer in the trench, a gate electrode on the insulation layer, an emitter electrode electrically connected to the emitter region and the floating layer, a second conductivity-type collector layer in the substrate, and a collector electrode on the collector layer. The floating layer has a lower impurity concentration than the channel layer. The floating layer has a first conductivity-type hole stopper layer located at a predetermined depth from the first surface of the substrate and at least partially spaced from the insulation layer.
    Type: Grant
    Filed: December 7, 2011
    Date of Patent: December 24, 2013
    Assignee: DENSO CORPORATION
    Inventors: Hiromitsu Tanabe, Yukio Tsuzuki, Kenji Kouno, Tomofusa Shiga
  • Publication number: 20120146091
    Abstract: An insulated gate semiconductor device includes a first conductivity-type semiconductor substrate, a second conductivity-type base layer on a first surface side of the substrate, a trench dividing the base layer into channel and floating layers, and a first conductivity-type emitter region that is formed in the channel layer and in contact with the trench. The semiconductor device includes a gate insulation layer in the trench, a gate electrode on the insulation layer, an emitter electrode electrically connected to the emitter region and the floating layer, a second conductivity-type collector layer in the substrate, and a collector electrode on the collector layer. The floating layer has a lower impurity concentration than the channel layer. The floating layer has a first conductivity-type hole stopper layer located at a predetermined depth from the first surface of the substrate and at least partially spaced from the insulation layer.
    Type: Application
    Filed: December 7, 2011
    Publication date: June 14, 2012
    Applicant: DENSO CORPORATION
    Inventors: Hiromitsu Tanabe, Yukio Tsuzuki, Kenji Kouno, Tomofusa Shiga
  • Publication number: 20120112273
    Abstract: A semiconductor device includes: a semiconductor substrate; a vertical type trench gate MOS transistor; a Schottky barrier diode; multiple trenches having a stripe pattern to divide an inner region into first and second separation regions; and a poly silicon film in each trench. The first separation region includes a first conductive type region for providing a source and a second conductive type layer for providing a channel region. The first conductive type region is adjacent to a first trench. The poly silicon film in the first trench is coupled with a gate wiring. A second trench is not adjacent to the first conductive type region. The poly silicon film in the second trench is coupled with a source or gate wiring. The substrate in the second separation region is coupled with the source wiring for providing a Schottky barrier.
    Type: Application
    Filed: January 18, 2012
    Publication date: May 10, 2012
    Applicant: DENSO CORPORATION
    Inventors: Takaaki AOKI, Tomofusa Shiga
  • Patent number: 8154073
    Abstract: A semiconductor device includes: a semiconductor substrate; a vertical type trench gate MOS transistor; a Schottky barrier diode; multiple trenches having a stripe pattern to divide an inner region into first and second separation regions; and a poly silicon film in each trench. The first separation region includes a first conductive type region for providing a source and a second conductive type layer for providing a channel region. The first conductive type region is adjacent to a first trench. The poly silicon film in the first trench is coupled with a gate wiring. A second trench is not adjacent to the first conductive type region. The poly silicon film in the second trench is coupled with a source or gate wiring. The substrate in the second separation region is coupled with the source wiring for providing a Schottky barrier.
    Type: Grant
    Filed: July 12, 2007
    Date of Patent: April 10, 2012
    Assignee: DENSO CORPORATION
    Inventors: Takaaki Aoki, Tetsuo Fujii, Tomofusa Shiga
  • Patent number: 7800195
    Abstract: A semiconductor apparatus is provided. The semiconductor apparatus includes a semiconductor substrate and a temperature sensing diode that is disposed on a surface part of the semiconductor substrate. A relation between a forward current flowing through the temperature sensing diode and a corresponding voltage drop across the temperature sensing diode varies with temperature. The semiconductor apparatus further includes a capacitor that is coupled with the temperature sensing diode, configured to reduce noise to act on the temperature sensing diode, and disposed such that the capacitor and the temperature sensing diode have a layered structure in a thickness direction of the semiconductor substrate.
    Type: Grant
    Filed: February 26, 2008
    Date of Patent: September 21, 2010
    Assignee: DENSO CORPORATION
    Inventors: Shoji Ozoe, Shoji Mizuno, Takaaki Aoki, Tomofusa Shiga
  • Patent number: 7622768
    Abstract: On the surface of a silicon nitride film, there is formed a thermal oxide film, over which a CVD oxide film is then formed to provide a silicon oxide film of two-layered structure films. Moreover, the total thickness of the two-layered structure films is set to a value from 5 nm to 30 nm. Thus, the silicon oxide film is made into the two-layered structure films of the thermal oxide film and the CVD oxide film to thereby achieve the thickness of the silicon oxide film. As a result, it is possible to prevent a Vth from being lowered by a charge trap phenomenon and to prevent the Vth from fluctuating due to the enlargement of the bird's beak length by the silicon oxide film.
    Type: Grant
    Filed: April 21, 2005
    Date of Patent: November 24, 2009
    Assignee: DENSO CORPORATION
    Inventors: Takaaki Aoki, Mikimasa Suzuki, Yukio Tsuzuki, Tomofusa Shiga
  • Patent number: 7420246
    Abstract: A vertical type semiconductor device includes: a silicon substrate having a first surface and a second surface; a first electrode disposed on the first surface of the silicon substrate; and a second electrode disposed on the second surface of the silicon substrate. Current is capable of flowing between the first electrode and the second electrode in a vertical direction of the silicon substrate. The second surface of the silicon substrate includes a re-crystallized silicon layer. The second electrode includes an aluminum film so that the aluminum film contacts the re-crystallized silicon layer with ohmic contact.
    Type: Grant
    Filed: May 30, 2006
    Date of Patent: September 2, 2008
    Assignee: DENSO CORPORATION
    Inventors: Shoji Ozoe, Tomofusa Shiga, Yoshifumi Okabe, Takaaki Aoki, Takeshi Fukazawa, Kimiharu Kayukawa
  • Publication number: 20080203389
    Abstract: A semiconductor apparatus is provided. The semiconductor apparatus includes a semiconductor substrate and a temperature sensing diode that is disposed on a surface part of the semiconductor substrate. A relation between a forward current flowing through the temperature sensing diode and a corresponding voltage drop across the temperature sensing diode varies with temperature. The semiconductor apparatus further includes a capacitor that is coupled with the temperature sensing diode, configured to reduce noise to act on the temperature sensing diode, and disposed such that the capacitor and the temperature sensing diode have a layered structure in a thickness direction of the semiconductor substrate.
    Type: Application
    Filed: February 26, 2008
    Publication date: August 28, 2008
    Applicant: DENSO CORPRORATION
    Inventors: Shoji Ozoe, Shoji Mizuno, Takaaki Aoki, Tomofusa Shiga
  • Publication number: 20080012050
    Abstract: A semiconductor device includes: a semiconductor substrate; a vertical type trench gate MOS transistor; a Schottky barrier diode; multiple trenches having a stripe pattern to divide an inner region into first and second separation regions; and a poly silicon film in each trench. The first separation region includes a first conductive type region for providing a source and a second conductive type layer for providing a channel region. The first conductive type region is adjacent to a first trench. The poly silicon film in the first trench is coupled with a gate wiring. A second trench is not adjacent to the first conductive type region. The poly silicon film in the second trench is coupled with a source or gate wiring. The substrate in the second separation region is coupled with the source wiring for providing a Schottky barrier.
    Type: Application
    Filed: July 12, 2007
    Publication date: January 17, 2008
    Applicant: DENSO CORPORATION
    Inventors: Takaaki Aoki, Tetsuo Fujii, Tomofusa Shiga
  • Publication number: 20060273351
    Abstract: A vertical type semiconductor device includes: a silicon substrate having a first surface and a second surface; a first electrode disposed on the first surface of the silicon substrate; and a second electrode disposed on the second surface of the silicon substrate. Current is capable of flowing between the first electrode and the second electrode in a vertical direction of the silicon substrate. The second surface of the silicon substrate includes a re-crystallized silicon layer. The second electrode includes an aluminum film so that the aluminum film contacts the re-crystallized silicon layer with ohmic contact.
    Type: Application
    Filed: May 30, 2006
    Publication date: December 7, 2006
    Applicant: DENSO CORPORATION
    Inventors: Shoji Ozoe, Tomofusa Shiga, Yoshifumi Okabe, Takaaki Aoki, Takeshi Fukazawa, Kimiharu Kayukawa
  • Patent number: 6974996
    Abstract: In a semiconductor device having a trench-gate structure in which polysilicon doped with boron is embedded in a trench, insulating film formed on the inner wall of the trench comprises ONO film, and silicon nitride film constituting the ONO film is formed to such film thickness and film quality that boron can be suppressed from passing through the silicon nitride film. Silicon oxide film is formed so that a top oxide film is thin and a bottom oxide film is thick.
    Type: Grant
    Filed: December 4, 2003
    Date of Patent: December 13, 2005
    Assignee: Denso Corporation
    Inventors: Tomofusa Shiga, Takaaki Aoki, Yoshifumi Okabe
  • Publication number: 20050236664
    Abstract: On the surface of a silicon nitride film, there is formed a thermal oxide film, over which a CVD oxide film is then formed to provide a silicon oxide film of two-layered structure films. Moreover, the total thickness of the two-layered structure films is set to a value from 5 nm to 30 nm. Thus, the silicon oxide film is made into the two-layered structure films of the thermal oxide film and the CVD oxide film to thereby achieve the thickness of the silicon oxide film. As a result, it is possible to prevent a Vth from being lowered by a charge trap phenomenon and to prevent the Vth from fluctuating due to the enlargement of the bird's beak length by the silicon oxide film.
    Type: Application
    Filed: April 21, 2005
    Publication date: October 27, 2005
    Inventors: Takaaki Aoki, Mikimasa Suzuki, Yukio Tsuzuki, Tomofusa Shiga
  • Publication number: 20040145012
    Abstract: In a semiconductor device having a trench-gate structure in which polysilicon doped with boron is embedded in a trench, insulating film formed on the inner wall of the trench comprises ONO film, and silicon nitride film constituting the ONO film is formed to such film thickness and film quality that boron can be suppressed from passing through the silicon nitride film. Silicon oxide film is formed so that a top oxide film is thin and a bottom oxide film is thick.
    Type: Application
    Filed: December 4, 2003
    Publication date: July 29, 2004
    Applicant: DENSO CORPORATION
    Inventors: Tomofusa Shiga, Takaaki Aoki, Yoshifumi Okabe