Patents by Inventor Masakatsu Hoshi

Masakatsu Hoshi 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: 20080108211
    Abstract: A method for producing a semiconductor device which includes: a semiconductor base, a hetero semiconductor region made of a semiconductor material different in band gap from a semiconductor material for the semiconductor base, and so configured as to form a hetero junction in combination with the semiconductor base, a gate insulating film so configured as to contact with the hetero junction between the semiconductor base and the hetero semiconductor region, a gate electrode so configured as to contact with the gate insulating film, a source electrode connected to the hetero semiconductor region, and a drain electrode connected to the semiconductor base. The method includes: forming the following in a self-aligning manner, by using a certain mask material: a source contact hole for the source electrode, and the gate electrode.
    Type: Application
    Filed: October 11, 2007
    Publication date: May 8, 2008
    Inventors: Tetsuya Hayashi, Masakatsu Hoshi, Hideaki Tanaka, Shigeharu Yamagami
  • Publication number: 20080026533
    Abstract: An aspect of the present invention provides a semiconductor device that includes a first conductivity type semiconductor body, a source region in contact with the semiconductor body, whose bandgap is different from that of the semiconductor body, and which formed heterojunction with the semiconductor body, a gate insulating film in contact with a portion of junction between the source region and the semiconductor body, a gate electrode in contact with the gate insulating film, a source electrode, a low resistance region in contact with the source electrode and the source region, and connected ohmically with the source electrode, and a drain electrode connected ohmically with the semiconductor body.
    Type: Application
    Filed: January 18, 2007
    Publication date: January 31, 2008
    Applicant: NISSAN MOTOR CO., LTD.
    Inventors: Tetsuya Hayashi, Hideaki Tanaka, Masakatsu Hoshi, Saichirou Kaneko
  • Publication number: 20080023707
    Abstract: A semiconductor device, includes: 1) an electric field relaxing area, including: i) a hetero junction formed by the followings: a) a first semiconductor material, and b) a second semiconductor material different from the first semiconductor material in band gap, and ii) an impurity introducing area so formed on the first semiconductor material as to contact the hetero junction.
    Type: Application
    Filed: July 27, 2006
    Publication date: January 31, 2008
    Inventors: Hideaki Tanaka, Masakatsu Hoshi, Yoshio Shimoida, Tetsuya Hayashi, Shigeharu Yamagami
  • Publication number: 20080009089
    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: July 5, 2007
    Publication date: January 10, 2008
    Inventors: Tetsuya HAYASHI, Masakatsu HOSHI, Yoshio SHIMOIDA, Hideaki TANAKA, Shigeharu YAMAGAMI
  • Publication number: 20070298586
    Abstract: The present invention provides a method of manufacturing a semiconductor device. The semiconductor device comprises a semiconductor base made of a first semiconductor material; and a hetero-semiconductor region made of a second semiconductor material having a different band gap from the first semiconductor material and forming a heterojunction with the semiconductor base. The formation of the heterojunction is accomplished by bonding together the semiconductor base and a substrate made of the second semiconductor material.
    Type: Application
    Filed: June 21, 2006
    Publication date: December 27, 2007
    Inventors: Hideaki Tanaka, Masakatsu Hoshi, Yoshio Shimoida, Tetsuya Hayashi
  • Publication number: 20070252168
    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: Application
    Filed: April 27, 2007
    Publication date: November 1, 2007
    Inventors: Yoshio Shimoida, Masakatsu Hoshi, Tetsuya Hayashi, Hideaki Tanaka, Shigeharu Yamagami
  • Publication number: 20070252172
    Abstract: A semiconductor device, includes: 1) a semiconductor base having a first face; 2) a hetero semiconductor region configured to contact the first face of the semiconductor base and different from the semiconductor base in band gap, the semiconductor base and the hetero semiconductor region defining therebetween a junction part in the hetero semiconductor region, a concentration of an impurity introduced in at least a first certain region including the junction part being less than or equal to a solid solution limit to a semiconductor material included in the hetero semiconductor region; 3) a gate electrode formed, via a gate insulation film, in a certain position adjacent to the junction part; 4) a source electrode configured to be connected to the hetero semiconductor region; and 5) a drain electrode configured to be connected to the semiconductor base.
    Type: Application
    Filed: April 27, 2007
    Publication date: November 1, 2007
    Inventors: Tetsuya Hayashi, Masakatsu Hoshi, Yoshio Shimoida, Hideaki Tanaka, Shigeharu Yamagami
  • Publication number: 20070252173
    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: Application
    Filed: April 27, 2007
    Publication date: November 1, 2007
    Inventors: Tetsuya Hayashi, Masakatsu Hoshi, Yoshio Shimoida, Hideaki Tanaka, Shigeharu Yamagami
  • Publication number: 20070252171
    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: Application
    Filed: April 26, 2007
    Publication date: November 1, 2007
    Inventors: Shigeharu Yamagami, Masakatsu Hoshi, Yoshio Shimoida, Tetsuya Hayashi, Hideaki Tanaka
  • Publication number: 20070252174
    Abstract: After a polycrystalline silicon as a hetero-semiconductor region forming a heterojunction with a semiconductor base is formed on an epitaxial layer configuring the semiconductor base, the unevenness on the surface of the polycrystalline silicon is planarized before a gate insulating film is formed. Alternatively, as the hetero-semiconductor region, amorphous or microcrystal hetero-semiconductor of which crystal grain diameter is small is used. When an amorphous or microcrystal hetero-semiconductor is deposited as the hetero-semiconductor region, a recrystallization annealing process of transforming into the polycrystalline silicon can be applied after the deposition. As a material of the semiconductor base, silicon carbide, gallium nitride or diamond can be used. As a material of the hetero-semiconductor region, silicon, silicon germanium, germanium, or gallium arsenide can be used.
    Type: Application
    Filed: April 25, 2007
    Publication date: November 1, 2007
    Inventors: Shigeharu Yamagami, Masakatsu Hoshi, Yoshio Shimoida, Tetsuya Hayashi, Hideaki Tanaka
  • Publication number: 20070235745
    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: Application
    Filed: April 10, 2007
    Publication date: October 11, 2007
    Inventors: Tetsuya Hayashi, Masakatsu Hoshi, Yoshio Shimoida, Hideaki Tanaka, Shigeharu Yamagami
  • Publication number: 20070221955
    Abstract: A trench is formed extending from a surface of a hetero semiconductor region of a polycrystal silicon to the drain region. Further, a driving point of the field effect transistor, where a gate insulating film, the hetero semiconductor region and the drain region are adjoined, is formed at a position spaced apart from a side wall of the trench.
    Type: Application
    Filed: March 15, 2007
    Publication date: September 27, 2007
    Applicant: Nissan Motor Co., Ltd.
    Inventors: Yoshio Shimoida, Tetsuya Hayashi, Hideaki Tanaka, Shigeharu Yamagami, Masakatsu Hoshi
  • Publication number: 20070218596
    Abstract: A method of manufacturing a semiconductor device is disclosed. The semiconductor device includes a semiconductor body of a first conductivity type, a hetero semiconductor region adjacent to one main surface of the semiconductor body and having a band gap different from that of the semiconductor body, and a gate electrode formed in a junction portion between the hetero semiconductor region and the semiconductor body through a gate insulating film. The method includes a first process of forming a predetermined trench by using a mask layer having a predetermined opening on one main surface side of the semiconductor body, a second process of forming a buried region adjacent to at least a side wall of the trench and so as to extend from the trench, a third process of forming a hetero semiconductor layer so as to adjoin the semiconductor body and the buried region, and a fourth process of forming the hetero semiconductor region by patterning the hetero semiconductor layer.
    Type: Application
    Filed: March 14, 2006
    Publication date: September 20, 2007
    Inventors: Tetsuya Hayashi, Masakatsu Hoshi, Yoshio Shimoida, Hideaki Tanaka
  • Publication number: 20070210330
    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: Application
    Filed: March 6, 2007
    Publication date: September 13, 2007
    Inventors: Tetsuya Hayashi, Masakatsu Hoshi, Yoshio Shimoida, Hideaki Tanaka, Shigeharu Yamagami
  • Publication number: 20070181886
    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: Application
    Filed: February 2, 2007
    Publication date: August 9, 2007
    Inventors: Yoshio Shimoida, Masakatsu Hoshi, Tetsuya Hayashi, Hideaki Tanaka, Shigeharu Yamagami
  • Patent number: 7217950
    Abstract: The present invention-provides a tunnel-injection device which encompasses, a reception layer made of a first semiconductor, a barrier-forming layer made of a second semiconductor having a bandgap-narrower than the first semiconductor, being in metallurgical contact with the reception layer, a gate insulating film disposed on the barrier-forming layer. The gate electrode controls the width of the barrier generated at the heterojunction interface between the reception layer and the barrier-forming layer so as to change the tunneling probability of carriers through the barrier. The device further encompasses a carrier receiving region being contact with the reception layer and a carrier-supplying region being contact with the barrier-forming layer.
    Type: Grant
    Filed: October 10, 2003
    Date of Patent: May 15, 2007
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Saichirou Kaneko, Masakatsu Hoshi, Kraisorn Throngnumchai, Tetsuya Hayashi, Hideaki Tanaka, Teruyoshi Mihara
  • Patent number: 7183575
    Abstract: A high reverse voltage diode includes a hetero junction made up from a silicon carbide base layer, which constitutes a first semiconductor base layer, and a polycrystalline silicon layer, which constitutes a second semiconductor layer, and whose band gap is different from that of the silicon carbide base layer. A low concentration N type polycrystalline silicon layer is deposited on a first main surface side of the silicon carbide base layer, and a metal electrode is formed on a second main surface side of the silicon carbide base layer which is opposite to the first main surface side thereof.
    Type: Grant
    Filed: February 19, 2003
    Date of Patent: February 27, 2007
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Yoshio Shimoida, Saichirou Kaneko, Hideaki Tanaka, Masakatsu Hoshi, Kraisom Throngnumchai, Teruyoshi Mihara, Tetsuya Hayashi
  • Patent number: 7173307
    Abstract: An aspect of the present invention provides a semiconductor device that includes a first conductivity type semiconductor body, a source region in contact with the semiconductor body, whose bandgap is different from that of the semiconductor body, and which formed heterojunction with the semiconductor body, a gate insulating film in contact with a portion of junction between the source region and the semiconductor body, a gate electrode in contact with the gate insulating film, a source electrode, a low resistance region in contact with the source electrode and the source region, and connected ohmically with the source electrode, and a drain electrode connected ohmically with the semiconductor body.
    Type: Grant
    Filed: September 23, 2004
    Date of Patent: February 6, 2007
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Tetsuya Hayashi, Hideaki Tanaka, Masakatsu Hoshi, Saichirou Kaneko
  • Patent number: 7151280
    Abstract: A semiconductor device includes a heterojunction semiconductor region 9, which forms a heterojunction with a drain region 2. The heterojunction semiconductor region 9 is connected to a source electrode 7, and has a band gap different from a band gap of a semiconductor substrate constituting the drain region 2. It is possible to set the size of an energy barrier against conduction electrons, which is formed between the drain region 2 and the heterojunction semiconductor region 9, into a desired size by changing the conductivity type or the impurity density of the heterojunction semiconductor region 9. This is a characteristic not found in a Schottky junction, in which the size of the energy barrier is inherently determined by a work function of a metal material. It is easy to achieve optimal design of a passive element in response to a withstand voltage system of a MOSFET as a switching element.
    Type: Grant
    Filed: December 16, 2004
    Date of Patent: December 19, 2006
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Tetsuya Hayashi, Masakatsu Hoshi, Saichirou Kaneko, Hideaki Tanaka
  • Patent number: 7138668
    Abstract: An aspect of the present invention provides a semiconductor device that includes a first semiconductor region of a first conductivity type and a second semiconductor region of a second conductivity type, having a different band gap from the first semiconductor region and forming a heterojunction with the first semiconductor region.
    Type: Grant
    Filed: July 26, 2004
    Date of Patent: November 21, 2006
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Tetsuya Hayashi, Hideaki Tanaka, Masakatsu Hoshi, Saichirou Kaneko