Patents by Inventor Yasuhiko OONISHI

Yasuhiko OONISHI 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: 20170025524
    Abstract: A semiconductor device includes an N-type silicon carbide layer, a P-type region, an N-type source region, a P-type contact region, a gate insulating film, a gate electrode, and a source electrode on the front surface side of an N-type silicon carbide substrate. A drain electrode is located on the back surface of the N-type silicon carbide substrate. A life time killer introduction region is located along an entire interface of the N-type silicon carbide layer and the bottom face of the P-type region. The life time killer is introduced by implanting helium or protons from the back surface side of the N-type silicon carbide substrate after forming a surface structure of an element on the front surface side of the N-type silicon carbide substrate and before forming the drain electrode.
    Type: Application
    Filed: October 3, 2016
    Publication date: January 26, 2017
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Akimasa KINOSHITA, Yasuyuki HOSHI, Yuichi HARADA, Yasuhiko OONISHI
  • Publication number: 20170025502
    Abstract: A semiconductor device having a silicon carbide (SiC) substrate, a SiC layer formed on a front surface of the SiC substrate, a first region selectively formed in the SiC layer at a surface thereof, a source region and a contact region formed in the first region, a gate insulating film disposed on the SiC layer and on a portion of the first region between the SiC layer and the source region, a gate electrode disposed on the gate insulating film above the portion of the first region, an interlayer insulating film covering the gate electrode, a source electrode electrically connected to the source region and the contact region, a drain electrode formed on a back surface of the SiC substrate, a first barrier film formed on, and covering, the interlayer insulating film, and a metal electrode formed on the source electrode and the first barrier film.
    Type: Application
    Filed: October 3, 2016
    Publication date: January 26, 2017
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Yuichi HARADA, Yasuyuki HOSHI, Akimasa KINOSHITA, Yasuhiko OONISHI
  • Publication number: 20170025503
    Abstract: A semiconductor device includes an n+-type source region having an impurity concentration higher than that of an n-type source region, formed in a surface layer of a p-type SiC layer and a p-type base region, farther on an outer side than the n-type source region, and contacting the n-type source region; an n-type region and an n+-type region having an impurity concentration higher than that of the n?-type SiC layer, formed in a portion of the n?-type SiC layer between p-type base regions and p-type SiC layers; and a second n-type region under the p-type base region and of a size smaller than that of the p-type base region, whereby low on-resistance and precision of the threshold voltage Vth are enhanced, increasing quality and enabling improved resistance to dielectric breakdown of the gate insulating film and resistance to breakdown.
    Type: Application
    Filed: October 3, 2016
    Publication date: January 26, 2017
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Yuichi HARADA, Yasuyuki HOSHI, Akimasa KINOSHITA, Yasuhiko OONISHI
  • Publication number: 20170025528
    Abstract: A semiconductor device, including a semiconductor substrate, a semiconductor layer disposed on a surface of the semiconductor substrate, a first semiconductor region disposed in the semiconductor layer at a surface thereof, a source region and a second semiconductor region disposed in the first semiconductor region at a surface thereof, a source electrode contacting the source region and the second semiconductor region, a gate insulating film disposed on the surface of the semiconductor layer and covering a portion of the first semiconductor region between the source region and the semiconductor layer, a gate electrode disposed on a surface of the gate insulating film, a drain electrode disposed on another surface of the semiconductor substrate, and a third semiconductor region, which has an impurity concentration higher than that of the first semiconductor region, formed in the semiconductor layer at the surface thereof and being electrically connected to the source electrode.
    Type: Application
    Filed: October 3, 2016
    Publication date: January 26, 2017
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Yasuyuki HOSHI, Yuichi HARADA, Akimasa KINOSHITA, Yasuhiko OONISHI
  • Publication number: 20170018615
    Abstract: A semiconductor device includes an N-type silicon carbide substrate, an N-type silicon carbide layer formed on the N-type silicon carbide substrate, a P-type region selectively formed in a surface layer of the N-type silicon carbide layer, an N-type source region formed in the P-type region, a P contact region formed in the P-type region, a gate insulating film formed on a portion of a region from the N-type source region, through the P-type region, to the N-type silicon carbide layer, a gate electrode formed on the gate insulating film, an interlayer insulating film covering the gate electrode, and a first source electrode electrically connected to a surface of the P contact region and the N-type source region. An end of the interlayer insulating film covering the gate electrode has a slope of a predetermined angle.
    Type: Application
    Filed: September 29, 2016
    Publication date: January 19, 2017
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Yuichi HARADA, Yasuyuki HOSHI, Akimasa KINOSHITA, Yasuhiko OONISHI
  • Publication number: 20170018609
    Abstract: A semiconductor device including a semiconductor substrate of a first conductivity type, a plurality of base regions of a second conductivity type formed on a first principal surface of the semiconductor substrate via a semiconductor layer of the first conductivity type, and a plurality of source regions of the first conductivity type formed in the base regions. Each base region, in a top-down view from an angle perpendicular to the first principle surface, is of a polygonal shape. Each adjacent two of the base regions in the top-down view have two sides, one from each of the two base regions, that face each other across a portion of the semiconductor layer, the source region being formed at only one of the two sides.
    Type: Application
    Filed: September 29, 2016
    Publication date: January 19, 2017
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Yasuyuki HOSHI, Yuichi HARADA, Akimasa KINOSHITA, Yasuhiko OONISHI
  • Publication number: 20160315187
    Abstract: A semiconductor device of an embodiment includes a p+-type region selectively disposed in a surface of an n-type silicon carbide epitaxial layer disposed on an n+-type silicon carbide substrate, an element structure that includes a source electrode and a p+-type region that form a metal-semiconductor junction on the n-type silicon carbide epitaxial layer, a p?-type region and another p?-type region that surround the periphery of the element structure, and an n+-type channel stopper region that surrounds the periphery of the p?-type regions so that the n-type silicon carbide epitaxial layer is therebetween. The n+-type channel stopper region has a second n+-type channel stopper region whose impurity concentration is high, and a first n+-type channel stopper region that encompasses the second n+-type channel stopper region and whose impurity concentration is lower than that of the second n+-type channel stopper region.
    Type: Application
    Filed: July 1, 2016
    Publication date: October 27, 2016
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Akimasa KINOSHITA, Yasuyuki HOSHI, Yuichi HARADA, Yasuhiko OONISHI