Patents by Inventor Shigeo Tooi
Shigeo Tooi 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).
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Patent number: 8129818Abstract: The present invention is a power device includes, a first conductive type semiconductor substrate, a second conductive type base region formed on a surface of the semiconductor substrate, a second conductive type collector region formed on a rear surface of the semiconductor substrate, a first conductive type emitter region formed on a surface of the base region, a trench gate formed via a gate insulating film in a first trench groove formed in the base region so as to penetrate the emitter region, a dent formed in the base region in proximity to the emitter region, a second conductive type contact layer formed on an inner wall of the dent, having a higher dopant density than that of the base region, a dummy trench formed via a dummy trench insulating film in a second trench groove formed at a bottom of the dent, and an emitter electrode electrically connected to the emitter region, the contact layer and the dummy trench, wherein the trench gate and the dummy trench reach the semiconductor substrate.Type: GrantFiled: October 14, 2008Date of Patent: March 6, 2012Assignee: Mitsubishi Electric CorporationInventors: Shigeo Tooi, Tetsujiro Tsunoda
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Publication number: 20110133312Abstract: The present invention is a power device includes, a first conductive type semiconductor substrate, a second conductive type base region formed on a surface of the semiconductor substrate, a second conductive type collector region formed on a rear surface of the semiconductor substrate, a first conductive type emitter region formed on a surface of the base region, a trench gate formed via a gate insulating film in a first trench groove formed in the base region so as to penetrate the emitter region, a dent formed in the base region in proximity to the emitter region, a second conductive type contact layer formed on an inner wall of the dent, having a higher dopant density than that of the base region, a dummy trench formed via a dummy trench insulating film in a second trench groove formed at a bottom of the dent, and an emitter electrode electrically connected to the emitter region, the contact layer and the dummy trench, wherein the trench gate and the dummy trench reach the semiconductor substrate.Type: ApplicationFiled: October 14, 2008Publication date: June 9, 2011Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Shigeo Tooi, Tetsujiro Tsunoda
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Patent number: 7772669Abstract: Second diffusion layers to be guard rings of a second conductivity type are formed on the major surface of a semiconductor substrate of a first conductivity type in a guard ring region. An insulating film is formed on these second diffusion layers. The semiconductor device has a structure wherein a conductive film is formed on the insulating film between adjacent electrodes among a first surface electrode, second surface electrodes, and a third surface electrode.Type: GrantFiled: October 2, 2006Date of Patent: August 10, 2010Assignee: Mitsubishi Electric CorporationInventors: Shigeo Tooi, Tetsujiro Tsunoda
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Publication number: 20070278672Abstract: Second diffusion layers to be guard rings of a second conductivity type are formed on the major surface of a semiconductor substrate of a first conductivity type in a guard ring region. An insulating film is formed on these second diffusion layers. The semiconductor device has a structure wherein a conductive film is formed on the insulating film between adjacent electrodes among a first surface electrode, second surface electrodes, and a third surface electrode.Type: ApplicationFiled: October 2, 2006Publication date: December 6, 2007Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Shigeo Tooi, Tetsujiro Tsunoda
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Semiconductor device with semiconductor chip formed by using wide gap semiconductor as base material
Patent number: 7057298Abstract: A switching chip using silicon as the base material is located on the upper surface of a cooling mechanism formed of a heat sink, an insulating substrate and a conductive plate, with a first conductive layer sandwiched in between. Further, a diode chip having a smaller area than a cathode electrode and using a wide gap semiconductor as the base material is located on the cathode electrode which has a smaller area than an anode electrode, with a second conductive layer sandwiched in between. A closed container encloses every structural component except an exposed portion of a bottom surface in the interior space.Type: GrantFiled: December 9, 2004Date of Patent: June 6, 2006Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Masayoshi Hirao, Katsumi Satou, Shigeo Tooi, Kazushige Matsuo -
Semiconductor device with semiconductor chip formed by using wide gap semiconductor as base material
Publication number: 20050098876Abstract: A switching chip using silicon as the base material is located on the upper surface of a cooling mechanism formed of a heat sink, an insulating substrate and a conductive plate, with a first conductive layer sandwiched in between. Further, a diode chip having a smaller area than a cathode electrode and using a wide gap semiconductor as the base material is located on the cathode electrode which has a smaller area than an anode electrode, with a second conductive layer sandwiched in between. A closed container encloses every structural component except an exposed portion of a bottom surface in the interior space.Type: ApplicationFiled: December 9, 2004Publication date: May 12, 2005Inventors: Masayoshi Hirao, Katsumi Satou, Shigeo Tooi, Kazushige Matsuo -
Semiconductor device with semiconductor chip formed by using wide gap semiconductor as base material
Patent number: 6861730Abstract: A switching chip (101) using silicon as the base material is located on the upper surface of a cooling mechanism formed of a heat sink (115), an insulating substrate (114) and a conductive plate (108), with a first conductive layer (109A) sandwiched in between. Further, a diode chip (102) having a smaller area than a cathode electrode (103) and using a wide gap semiconductor as the base material is located on the cathode electrode (103) which has a smaller area than an anode electrode (105), with a second conductive layer (109B) sandwiched in between. A closed container (117) encloses every structural component except an exposed portion of a bottom surface (115BS) in the interior space.Type: GrantFiled: February 26, 2004Date of Patent: March 1, 2005Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Masayoshi Hirao, Katsumi Satou, Shigeo Tooi, Kazushige Matsuo -
Semiconductor device with semiconductor chip formed by using wide gap semiconductor as base material
Patent number: 6831351Abstract: A switching chip (101) using silicon as the base material is located on the upper surface of a cooling mechanism formed of a heat sink (115), an insulating substrate (114) and a conductive plate (108), with a first conductive layer (109A) sandwiched in between. Further, a diode chip (102) having a smaller area than a cathode electrode (103) and using a wide gap semiconductor as the base material is located on the cathode electrode (103) which has a smaller area than an anode electrode (105), with a second conductive layer (109B) sandwiched in between. A closed container (117) encloses every structural component except an exposed portion of a bottom surface (115BS) in the interior space.Type: GrantFiled: August 1, 2002Date of Patent: December 14, 2004Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Masayoshi Hirao, Katsumi Satou, Shigeo Tooi, Kazushige Matsuo -
Semiconductor device with semiconductor chip formed by using wide gap semiconductor as base material
Publication number: 20040164403Abstract: A switching chip (101) using silicon as the base material is located on the upper surface of a cooling mechanism formed of a heat sink (115), an insulating substrate (114) and a conductive plate (108), with a first conductive layer (109A) sandwiched in between. Further, a diode chip (102) having a smaller area than a cathode electrode (103) and using a wide gap semiconductor as the base material is located on the cathode electrode (103) which has a smaller area than an anode electrode (105), with a second conductive layer (109B) sandwiched in between. A closed container (117) encloses every structural component except an exposed portion of a bottom surface (115BS) in the interior space.Type: ApplicationFiled: February 26, 2004Publication date: August 26, 2004Applicant: MITSUBISHI DENKI KABUSHIKI KAISHAInventors: Masayoshi Hirao, Katsumi Satou, Shigeo Tooi, Kazushige Matsuo -
Patent number: 6649995Abstract: A Schottky diode that achieves a predetermined reverse-direction breakdown voltage even if a state of a surface in a vicinity of a Schottky junction interface changes due to a welding of a bonding wire. The semiconductor device having the Schottky junction includes a semiconductor substrate of a first conductivity type. A well region of a second conductivity type is formed in a top surface of the semiconductor substrate. A Schottky electrode is formed on the top surface of the semiconductor substrate. A connecting conductive member is electrically connected to the Schottky electrode. The connecting conductive member is selectively connected to the Schottky electrode above the well region such that a connection surface between the connecting conductive member and the Schottky electrode is not extended above a Schottky junction between the Schottky electrode and the semiconductor substrate of the first conductivity type.Type: GrantFiled: April 22, 2002Date of Patent: November 18, 2003Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Shigeo Tooi, Katsumi Satoh
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Semiconductor device with semiconductor chip formed by using wide gap semiconductor as base material
Publication number: 20030155644Abstract: A switching chip (101) using silicon as the base material is located on the upper surface of a cooling mechanism formed of a heat sink (115), an insulating substrate (114) and a conductive plate (108), with a first conductive layer (109A) sandwiched in between. Further, a diode chip (102) having a smaller area than a cathode electrode (103) and using a wide gap semiconductor as the base material is located on the cathode electrode (103) which has a smaller area than an anode electrode (105), with a second conductive layer (109B) sandwiched in between. A closed container (117) encloses every structural component except an exposed portion of a bottom surface (115BS) in the interior space.Type: ApplicationFiled: August 1, 2002Publication date: August 21, 2003Applicant: MITSUBISHI DENKI KABUSHIKIInventors: Masayoshi Hirao, Katsumi Satou, Shigeo Tooi -
Publication number: 20030075728Abstract: The present invention has a purpose to provide a Schottky diode allowing obtaining a predetermined reverse-direction breakdown voltage even if a surface state in the vicinity of a Schottky junction interface changes due to the welding of the bonding wire. The semiconductor device having a Schottky junction includes a semiconductor substrate of the first conductivity type. A well region of the second conductivity type is formed in the top surface of the semiconductor substrate. A Schottky electrode is formed on the top surface of the semiconductor substrate and has a Schottky junction with the semiconductor substrate. A connecting conductive member is electrically connected on the Schottky electrode. And, the connecting conductive member is selectively connected with the Schottky electrode above the well region.Type: ApplicationFiled: April 22, 2002Publication date: April 24, 2003Applicant: MITSUBISHI DENKI KABUSHIKI KAISHAInventors: Shigeo Tooi, Katsumi Satoh