Patents by Inventor Shigeharu Yamagami

Shigeharu Yamagami 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: 8164116
    Abstract: A semiconductor device includes: a semiconductor base; a hetero semiconductor region which is in contact with the semiconductor base and which has a band gap different from that of the semiconductor base; a first electrode connected to the hetero semiconductor region; and a second electrode forming an ohmic contact to the semiconductor base. The hetero semiconductor region includes a laminated hetero semiconductor region formed by laminating a plurality of semiconductor layers in which crystal alignment is discontinuous at a boundary between at least two layers.
    Type: Grant
    Filed: August 22, 2006
    Date of Patent: April 24, 2012
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Tetsuya Hayashi, Yoshio Shimoida, Masakatsu Hoshi, Hideaki Tanaka, Shigeharu Yamagami
  • Patent number: 8067776
    Abstract: Methods of manufacturing a semiconductor device including a semiconductor substrate and a hetero semiconductor region including a semiconductor material having a band gap different from that of the semiconductor substrate and contacting a portion of a first surface of the semiconductor substrate are taught herein, as are the resulting devices. The method comprises depositing a first insulating film on exposed portions of the first surface of the semiconductor substrate and on exposed surfaces of the hetero semiconductor material and forming a second insulating film between the first insulating film and facing surfaces of the semiconductor substrate and the hetero semiconductor region by performing a thermal treatment in an oxidizing atmosphere.
    Type: Grant
    Filed: April 18, 2008
    Date of Patent: November 29, 2011
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Shigeharu Yamagami, Masakatsu Hoshi, Tetsuya Hayashi, Hideaki Tanaka
  • Patent number: 7989295
    Abstract: A semiconductor substrate made of a semiconductor material is prepared, and a hetero semiconductor region is formed on the semiconductor substrate to form a heterojunction in an interface between the hetero semiconductor region and the semiconductor substrate. The hetero semiconductor region is made of a semiconductor material having a bandgap different from that of the semiconductor material, and a part of the hetero semiconductor region includes a film thickness control portion whose film thickness is thinner than that of the other part thereof. By oxidizing the hetero semiconductor region with a thickness equal to the film thickness of the film thickness control portion, a gate insulating film adjacent to the heterojunction is formed. A gate electrode is formed on the gate insulating film. This makes it possible to manufacture a semiconductor device including the gate insulating film with a lower ON resistance, and with a higher insulating characteristic and reliability.
    Type: Grant
    Filed: January 26, 2011
    Date of Patent: August 2, 2011
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Tetsuya Hayashi, Masakatsu Hoshi, Yoshio Shimoida, Hideaki Tanaka, Shigeharu Yamagami
  • Publication number: 20110117699
    Abstract: A semiconductor substrate made of a semiconductor material is prepared, and a hetero semiconductor region is formed on the semiconductor substrate to form a heterojunction in an interface between the hetero semiconductor region and the semiconductor substrate. The hetero semiconductor region is made of a semiconductor material having a bandgap different from that of the semiconductor material, and a part of the hetero semiconductor region includes a film thickness control portion whose film thickness is thinner than that of the other part thereof. By oxidizing the hetero semiconductor region with a thickness equal to the film thickness of the film thickness control portion, a gate insulating film adjacent to the heterojunction is formed. A gate electrode is formed on the gate insulating film. This makes it possible to manufacture a semiconductor device including the gate insulating film with a lower ON resistance, and with a higher insulating characteristic and reliability.
    Type: Application
    Filed: January 26, 2011
    Publication date: May 19, 2011
    Inventors: Tetsuya HAYASHI, Masakatsu Hoshi, Yoshio Shimoida, Hideaki Tanaka, Shigeharu Yamagami
  • Patent number: 7910923
    Abstract: A semiconductor device with superior long-term reliability is disclosed that alleviates current concentration into a switch structure arranged at an outermost portion. The semiconductor device comprises hetero semiconductor regions formed of polycrystalline silicon having a band gap width different from that of a drift region and hetero-adjoined with the drift region, a gate insulation film, a gate electrode adjoined to the gate insulation film, a source electrode connected to a source contact portion of the hetero semiconductor regions and an outermost switch structure and a repeating portion switch structure with a drain electrode connected to a substrate region. In a conduction state, the outermost switch structure comprises a mechanism in which the current flowing at the outermost switch structure becomes smaller than the current flowing at the repeating portion switch structure.
    Type: Grant
    Filed: December 20, 2007
    Date of Patent: March 22, 2011
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Tetsuya Hayashi, Masakatsu Hoshi, Hideaki Tanaka, Shigeharu Yamagami
  • Patent number: 7902025
    Abstract: A semiconductor substrate made of a semiconductor material is prepared, and a hetero semiconductor region is formed on the semiconductor substrate to form a heterojunction in an interface between the hetero semiconductor region and the semiconductor substrate. The hetero semiconductor region is made of a semiconductor material having a bandgap different from that of the semiconductor material, and a part of the hetero semiconductor region includes a film thickness control portion whose film thickness is thinner than that of the other part thereof. By oxidizing the hetero semiconductor region with a thickness equal to the film thickness of the film thickness control portion, a gate insulating film adjacent to the heterojunction is formed. A gate electrode is formed on the gate insulating film. This makes it possible to manufacture a semiconductor device including the gate insulating film with a lower ON resistance, and with a higher insulating characteristic and reliability.
    Type: Grant
    Filed: July 5, 2007
    Date of Patent: March 8, 2011
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Tetsuya Hayashi, Masakatsu Hoshi, Yoshio Shimoida, Hideaki Tanaka, Shigeharu Yamagami
  • Patent number: 7902555
    Abstract: A hetero semiconductor corner region, which is a current-concentration relief region that keeps a reverse bias current from concentrating on the convex corner, is arranged in a hetero semiconductor region. Thereby, a current concentration on the convex corner can be prevented. As a result, an interrupting performance can be improved at the time of interruption, and at the same time, the generation of the hot spot where in a specific portion is prevented at the time of conduction to suppress deterioration in a specific portion, thereby ensuring a long-term reliability.
    Type: Grant
    Filed: December 1, 2008
    Date of Patent: March 8, 2011
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Tetsuya Hayashi, Masakatsu Hoshi, Hideaki Tanaka, Shigeharu Yamagami
  • Patent number: 7880199
    Abstract: A semiconductor device is provided with: a semiconductor substrate of a predetermined electroconduction type; a hetero semiconductor region contacted with a first main surface of the semiconductor substrate and comprising a semiconductor material having a bandgap different from that of the semiconductor substrate; a gate electrode formed through a gate insulator layer at a position adjacent to a junction region between the hetero semiconductor region and the semiconductor substrate; a source electrode connected to the hetero semiconductor region; and a drain electrode connected to the semiconductor substrate; wherein the hetero semiconductor region includes a contact portion contacted with the source electrode, at least a partial region of the contact portion is of the same electroconduction type as the electroconduction type of the semiconductor substrate, and the partial region has an impurity concentration higher than an impurity concentration of at least that partial region of a gate-electrode facing port
    Type: Grant
    Filed: April 27, 2007
    Date of Patent: February 1, 2011
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Tetsuya Hayashi, Masakatsu Hoshi, Yoshio Shimoida, Hideaki Tanaka, Shigeharu Yamagami
  • Patent number: 7859015
    Abstract: A semiconductor device is provided with a semiconductor region, a gate electrode, a source electrode and a drain electrode. The semiconductor region is formed on a semiconductor substrate surface and includes a first semiconductor portion of a first conducting type, a second semiconductor portion of a second conducting type, a band gap distinct from the substrate's band gap, more than two accumulated semiconductor layers, and junctions between the layers. The semiconductor layers each contain an impurity of the first conducting type. The gate electrode adjoins a heterojunction between the second semiconductor portion and the semiconductor substrate through a gate insulation film. The source electrode is coupled to the semiconductor region. The drain electrode is coupled to the semiconductor substrate.
    Type: Grant
    Filed: April 14, 2009
    Date of Patent: December 28, 2010
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Yoshio Shimoida, Masakatsu Hoshi, Tetsuya Hayashi, Hideaki Tanaka, Shigeharu Yamagami
  • Patent number: 7830703
    Abstract: A semiconductor device having SRAM cell units each comprising a pair of a first driving transistor and a second driving transistor, a pair of a first load transistor and a second load transistor, and a pair of a first access transistor and a second access transistor, wherein each of the transistors comprises a semiconductor layer projecting upward from a substrate plane, a gate electrode extending on opposite sides of the semiconductor layer so as to stride over a top of the semiconductor layer, a gate insulating film interposed between the gate electrode and the semiconductor layer, and a pair of source/drain areas formed in the semiconductor layer; and the first and second driving transistors each have a channel width larger than that of at least either each of the load transistors or each of the access transistors.
    Type: Grant
    Filed: May 25, 2005
    Date of Patent: November 9, 2010
    Assignee: NEC Corporation
    Inventors: Koichi Takeda, Masahiro Nomura, Kiyoshi Takeuchi, Hitoshi Wakabayashi, Shigeharu Yamagami, Risho Koh, Koichi Terashima, Katsuhiko Tanaka, Masayasu Tanaka
  • Patent number: 7807534
    Abstract: A method for producing a semiconductor device includes forming a first hetero-semiconductor layer as a hetero-junction to a surface of a silicon carbide epitaxial layer. This layer is composed of polycrystalline silicon having a band gap different from that of the silicon carbide epitaxial layer. An etching stopper layer composed of a material having a different etching rate from that of the polycrystalline silicon is formed on the surface of the first hetero-semiconductor layer. A second hetero-semiconductor layer composed of polycrystalline silicon is formed so that the second hetero-semiconductor layer contacts the surface of the first hetero-semiconductor layer and the etching stopper layer. The etching stopper layer is removed, the first hetero-semiconductor layer is thermally oxidized, and the thermally oxidized portion is then removed.
    Type: Grant
    Filed: February 19, 2008
    Date of Patent: October 5, 2010
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Hideaki Tanaka, Masakatsu Hoshi, Tetsuya Hayashi, Shigeharu Yamagami
  • Patent number: 7781786
    Abstract: Impurity concentration of a second semiconductor region is set such that when a predetermined reverse bias is applied to a heterojunction diode configured by a first semiconductor region and the second semiconductor region, a breakdown voltage at least in a heterojunction region other than outer peripheral ends of the heterojunction diode is a breakdown voltage of a semiconductor device.
    Type: Grant
    Filed: April 10, 2007
    Date of Patent: August 24, 2010
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Tetsuya Hayashi, Masakatsu Hoshi, Yoshio Shimoida, Hideaki Tanaka, Shigeharu Yamagami
  • Patent number: 7781802
    Abstract: As semiconductor regions in contact with a first main surface of a semiconductor base composed by forming an N? silicon carbide epitaxial layer on an N+ silicon carbide substrate connected to a cathode electrode, there are provided both of an N+ polycrystalline silicon layer of a same conduction type as a conduction type of the semiconductor base and a P+ polycrystalline silicon layer of a conduction type different from the conduction type of the semiconductor base. Both of the N+ polycrystalline silicon layer and the P+ polycrystalline silicon layer are hetero-joined to the semiconductor base, and are ohmically connected to the anode electrode.
    Type: Grant
    Filed: April 26, 2007
    Date of Patent: August 24, 2010
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Shigeharu Yamagami, Masakatsu Hoshi, Yoshio Shimoida, Tetsuya Hayashi, Hideaki Tanaka
  • Patent number: 7768035
    Abstract: A semiconductor device has a semiconductor base of a first conductivity type; a hetero semiconductor region in contact with the semiconductor base; a gate electrode adjacent to a portion of a junction between the hetero semiconductor region and the semiconductor base across a gate insulating film; a source electrode connected to the hetero semiconductor region; and a drain electrode connected to the semiconductor base. The hetero semiconductor region has a band gap different from that of the semiconductor base. The hetero semiconductor region includes a first hetero semiconductor region and a second hetero semiconductor region. The first hetero semiconductor region is formed before the gate insulating film is formed. The second hetero semiconductor region is formed after the gate insulating film is formed.
    Type: Grant
    Filed: August 2, 2006
    Date of Patent: August 3, 2010
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Yoshio Shimoida, Tetsuya Hayashi, Masakatsu Hoshi, Hideaki Tanaka, Shigeharu Yamagami
  • Patent number: 7749845
    Abstract: A method of manufacturing a semiconductor device having a polycrystalline silicon layer (5) includes; a step of forming a mask layer (7) on the polycrystalline silicon layer (5); a step of forming a side wall (8) that is provided on a side face of the mask layer (7) and covers part of the polycrystalline silicon layer (6); a step of doping an impurity (52) into the polycrystalline silicon layer (5) by using at least one of the mask layer (7) and the side wall (8) as a mask; and a step of etching the polycrystalline silicon layer (5, 6) by using at least one of the mask layer (7) and the side wall (8) as a mask.
    Type: Grant
    Filed: June 26, 2006
    Date of Patent: July 6, 2010
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Shigeharu Yamagami, Masakatsu Hoshi, Tetsuya Hayashi, Hideaki Tanaka, Yoshio Shimoida
  • Patent number: 7719043
    Abstract: The present invention relates to a semiconductor device including a Fin type field effect transistor (FET) having a protrusive semiconductor layer protruding from a substrate plane, a gate electrode formed so as to straddle the protrusive semiconductor layer, a gate insulating film between the gate electrode and the protrusive semiconductor layer, and source and drain regions provided in the protrusive semiconductor layer, wherein the semiconductor device has on a semiconductor substrate an element forming region having a Fin type FET, a trench provided on the semiconductor substrate for separating the element forming region from another element forming region, and an element isolation insulating film in the trench; the element forming region has a shallow substrate flat surface formed by digging to a depth shallower than the bottom surface of the trench and deeper than the upper surface of the semiconductor substrate, a semiconductor raised portion protruding from the substrate flat surface and formed of a p
    Type: Grant
    Filed: July 4, 2005
    Date of Patent: May 18, 2010
    Assignee: NEC Corporation
    Inventors: Shigeharu Yamagami, Hitoshi Wakabayashi, Risho Koh, Kiyoshi Takeuchi, Masahiro Nomura, Koichi Takeda, Koichi Terashima, Masayasu Tanaka, Katsuhiko Tanaka
  • Patent number: 7714352
    Abstract: A semiconductor device, includes: a first conductivity-semiconductor substrate; a hetero semiconductor region for forming a hetero junction with the first conductivity-semiconductor substrate; a gate electrode adjacent to a part of the hetero junction by way of a gate insulating film; a drain electrode connecting to the first conductivity-semiconductor substrate; a source electrode connecting to the hetero semiconductor region; and a second conductivity-semiconductor region formed on a part of a first face of the first conductivity-semiconductor substrate in such a configuration as to oppose the gate electrode via the gate insulating film, the gate insulating film, the hetero semiconductor region and the first conductivity-semiconductor substrate contacting each other to thereby form a triple contact point.
    Type: Grant
    Filed: February 2, 2007
    Date of Patent: May 11, 2010
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Yoshio Shimoida, Masakatsu Hoshi, Tetsuya Hayashi, Hideaki Tanaka, Shigeharu Yamagami
  • Patent number: 7701018
    Abstract: A semiconductor device comprising a first semiconductor region and a second semiconductor region, (a) wherein a field effect transistor is comprised of the first semiconductor region comprising at least one semiconductor layer(s) protruding upward from a substrate, a gate electrode(s) formed via an insulating film such that the gate electrode(s) strides over the semiconductor layer(s) and source/drain regions provided in the semiconductor layer(s) on both sides of the gate electrode(s), whereby a channel region is formed in at least both sides of the semiconductor layer(s), (b) wherein the second semiconductor region comprises semiconductor layers protruding upward from the substrate and placed, at least opposing the first semiconductor region at both ends in the direction perpendicular to a channel current direction and the side surface of the semiconductor layers facing the first semiconductor region is parallel to the channel current direction.
    Type: Grant
    Filed: March 22, 2005
    Date of Patent: April 20, 2010
    Assignee: NEC Corporation
    Inventors: Shigeharu Yamagami, Hitoshi Wakabayashi, Kiyoshi Takeuchi, Atsushi Ogura, Masayasu Tanaka, Masahiro Nomura, Koichi Takeda, Toru Tatsumi, Koji Watanabe, Koichi Terashima
  • Patent number: 7695997
    Abstract: An electrostatic discharge protection element and a protection resistor, which are formed on an N? drain region with a field oxide film interposed therebetween for the purpose of preventing electrical breakdown of a field effect transistor, are composed as a stacked bidirectional Zener diode of one or a plurality of N+ polycrystalline silicon regions of a first layer and a P+ polycrystalline silicon region of a second layer, and a stacked resistor of one or a plurality of N+ resistor layers of the first layer and an N+ resistor layer of the second layer, respectively. One end of the plurality of N+ polycrystalline silicon regions of the first layer is connected to an external gate electrode terminal, and the other end is connected to a source electrode. One end of the plurality of N+ resistor layers of the first layer is connected to a gate electrode, and the other end is connected to the external gate electrode terminal.
    Type: Grant
    Filed: April 27, 2007
    Date of Patent: April 13, 2010
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Yoshio Shimoida, Masakatsu Hoshi, Tetsuya Hayashi, Hideaki Tanaka, Shigeharu Yamagami
  • Patent number: 7671383
    Abstract: A semiconductor device, includes: a first conductivity type semiconductor base having a main face; a hetero semiconductor region contacting the main face of the semiconductor base and forming a hetero junction in combination with the semiconductor base, the semiconductor base and the hetero semiconductor region in combination defining a junction end part; a gate insulating film defining a junction face in contact with the semiconductor base and having a thickness; and a gate electrode disposed adjacent to the junction end part via the gate insulating film and defining a shortest point in a position away from the junction end part by a shortest interval, a line extending from the shortest point to a contact point vertically relative to the junction face, forming such a distance between the contact point and the junction end part as to be smaller than the thickness of the gate insulating film contacting the semiconductor base.
    Type: Grant
    Filed: March 6, 2007
    Date of Patent: March 2, 2010
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Tetsuya Hayashi, Masakatsu Hoshi, Yoshio Shimoida, Hideaki Tanaka, Shigeharu Yamagami