Patents by Inventor Yoichiro Tarui
Yoichiro Tarui 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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Publication number: 20230147932Abstract: The present disclosure relates a semiconductor device using a super junction structure, and includes: a semiconductor base body of a first conductivity type; a pillar part including a plurality of first pillars of a first conductivity type and a plurality of second pillars of a second conductivity type provided on the semiconductor base body to protrude in a thickness direction of the semiconductor base body; a pillar surrounding part of a first conductivity type or a second conductivity type provided around the pillar part; and a semiconductor element in which the pillar part is provided as an active region, wherein the plurality of first and second pillars have a striped shape in a plan view, and are alternately arranged in parallel to each other in a pillar width direction perpendicular to a longitudinal direction of each of the pillars.Type: ApplicationFiled: June 24, 2020Publication date: May 11, 2023Applicant: Mitsubishi Electric CorporationInventors: Yoichiro TARUI, Nobuo FUJIWARA, Takanori TANAKA
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Publication number: 20220199811Abstract: Provided is a technology that suppresses the removal of collector layers in the planarization process while suppressing the snapback phenomenon. A semiconductor device related to a technology disclosed in the present specification includes a drain layer of first conductivity type in a part of a lower surface a drift layer, a plurality of collector layers of second conductivity type in parts of the lower surface of the drift layer, and a dummy layer of the first conductivity type interposed between the plurality of collector layers in parts of the lower surface of the drift layer, in which a width of the dummy layer 3 in a first direction, which is the direction in which the dummy layer is interposed between the plurality of collector layers, is narrower than a width of the drain layer in the first direction.Type: ApplicationFiled: May 29, 2019Publication date: June 23, 2022Applicant: Mitsubishi Electric CorporationInventors: Kazuya KONISHI, Yoichiro TARUI, Hiroki NIWA, Hiroaki OKABE, Hiroshi WATANABE
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Patent number: 11125803Abstract: The present application relates to a technique of reducing the occurrence of a spot breakdown near a probe needle with the intention of preventing damage on the probe needle during a test implemented by applying a high voltage to a semiconductor device. In a method of measuring a semiconductor device, the semiconductor device includes: a semiconductor substrate (1), an epitaxial layer (2), at least one second conductivity type region (3) of a second conductivity type formed in a part of the surface layer of the epitaxial layer to have a contour, a Schottky electrode (11), an anode electrode (12), and a cathode electrode (13). A voltage is applied while the probe needle (21) is brought into contact with the upper surface of the anode electrode in a range in which the contour of the at least one second conductivity type region is formed in a plan view.Type: GrantFiled: September 1, 2016Date of Patent: September 21, 2021Assignee: Mitsubishi Electric CorporationInventors: Koji Okuno, Shozo Shikama, Yoichiro Tarui
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Patent number: 11094790Abstract: A present invention includes the following: a third impurity region having a second conductivity type and disposed in an outer peripheral region that is the outer periphery of a cell arrangement region in which a unit cell is disposed; a field insulating film disposed in the outer peripheral region; an interlayer insulating film; a first main electrode disposed on the interlayer insulating film. The third impurity region includes a fourth impurity region having the second conductivity type, having a higher impurity concentration than the third impurity region. A gate wire and a gate pad are disposed in the outer peripheral region. The fourth impurity region is adjacent to the cell arrangement region, surrounds at least a region below the gate pad, and is electrically connected to the first main electrode.Type: GrantFiled: September 23, 2016Date of Patent: August 17, 2021Assignee: Mitsubishi Electric CorporationInventors: Yasunori Oritsuki, Yoichiro Tarui
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Patent number: 11056562Abstract: A present invention includes the following: a third impurity region having a second conductivity type and disposed in an outer peripheral region that is the outer periphery of a cell arrangement region in which a unit cell is disposed; a field insulating film disposed in the outer peripheral region; an interlayer insulating film; a first main electrode disposed on the interlayer insulating film. The third impurity region includes a fourth impurity region having the second conductivity type, having a higher impurity concentration than the third impurity region. A gate wire and a gate pad are disposed in the outer peripheral region. The fourth impurity region is adjacent to the cell arrangement region, surrounds at least a region below the gate pad, and is electrically connected to the first main electrode.Type: GrantFiled: September 23, 2016Date of Patent: July 6, 2021Assignee: Mitsubishi Electric CorporationInventors: Yasunori Oritsuki, Yoichiro Tarui
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Patent number: 10665713Abstract: A silicon carbide semiconductor device includes a silicon carbide semiconductor substrate having an n-type drift layer, and a p-type well region formed in a surface portion of a part of the drift layer, an insulating film provided on the well region, a gate built-in resistor formed of polysilicon in contact with a surface of the insulating film, an interlayer insulating film formed on the gate built-in resistor, a gate contact wire that is connected to a gate pad and formed on the interlayer insulating film, a gate wire provided on the interlayer insulating layer so as to be apart from the gate contact wire, a first gate contact for electrically connecting the gate contact wire and the gate built-in resistor, and a second gate contact for electrically connecting the gate wire and the gate built-in resistor.Type: GrantFiled: July 23, 2018Date of Patent: May 26, 2020Assignee: Mitsubishi Electric CorporationInventors: Takaaki Tominaga, Yasushi Takaki, Yoichiro Tarui, Shiro Hino
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Publication number: 20190310306Abstract: The present application relates to a technique of reducing the occurrence of a spot breakdown near a probe needle with the intention of preventing damage on the probe needle during a test implemented by applying a high voltage to a semiconductor device. In a method of measuring a semiconductor device, the semiconductor device includes: a semiconductor substrate (1), an epitaxial layer (2), at least one second conductivity type region (3) of a second conductivity type formed in a part of the surface layer of the epitaxial layer to have a contour, a Schottky electrode (11), an anode electrode (12), and a cathode electrode (13). A voltage is applied while the probe needle (21) is brought into contact with the upper surface of the anode electrode in a range in which the contour of the at least one second conductivity type region is formed in a plan view.Type: ApplicationFiled: September 1, 2016Publication date: October 10, 2019Applicant: Mitsubishi Electric CorporationInventors: Koji OKUNO, Shozo SHIKAMA, Yoichiro TARUI
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Publication number: 20190259845Abstract: A present invention includes the following: a third impurity region having a second conductivity type and disposed in an outer peripheral region that is the outer periphery of a cell arrangement region in which a unit cell is disposed; a field insulating film disposed in the outer peripheral region; an interlayer insulating film; a first main electrode disposed on the interlayer insulating film. The third impurity region includes a fourth impurity region having the second conductivity type, having a higher impurity concentration than the third impurity region. A gate wire and a gate pad are disposed in the outer peripheral region. The fourth impurity region is adjacent to the cell arrangement region, surrounds at least a region below the gate pad, and is electrically connected to the first main electrode.Type: ApplicationFiled: September 23, 2016Publication date: August 22, 2019Applicant: Mitsubishi Electric CorporationInventors: Yasunori ORITSUKI, Yoichiro TARUI
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Publication number: 20190097043Abstract: A silicon carbide semiconductor device includes a silicon carbide semiconductor substrate having an n-type drift layer, and a p-type well region formed in a surface portion of a part of the drift layer, an insulating film provided on the well region, a gate built-in resistor formed of polysilicon in contact with a surface of the insulating film, an interlayer insulating film formed on the gate built-in resistor, a gate contact wire that is connected to a gate pad and formed on the interlayer insulating film, a gate wire provided on the interlayer insulating layer so as to be apart from the gate contact wire, a first gate contact for electrically connecting the gate contact wire and the gate built-in resistor, and a second gate contact for electrically connecting the gate wire and the gate built-in resistor.Type: ApplicationFiled: July 23, 2018Publication date: March 28, 2019Applicant: Mitsubishi Electric CorporationInventors: Takaaki TOMINAGA, Yasushi TAKAKI, Yoichiro TARUI, Shiro HINO
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Patent number: 10128340Abstract: The present invention relates to a power semiconductor device which includes: a first conductivity-type silicon carbide semiconductor layer; a switching device which is formed on the silicon carbide semiconductor layer; a second conductivity-type electric field relaxation impurity region which is formed in a terminal portion of a formation region of the switching device and which relaxes an electric field of the terminal portion; and a first conductivity-type added region which is provided between second conductivity-type well regions of a plurality of unit cells that constitutes the switching device, and at least on an outer side of the electric field relaxation impurity region, and which has an impurity concentration higher than that in the silicon carbide semiconductor layer.Type: GrantFiled: March 18, 2015Date of Patent: November 13, 2018Assignee: Mitsubishi Electric CorporationInventors: Yoichiro Tarui, Toshikazu Tanioka, Yasunori Oritsuki
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Patent number: 9985124Abstract: The present invention can reduce an on-resistance while suppressing reduction in a short circuit capacity. The present invention includes a SiC epitaxial layer, a well region, a source region, a channel resistance adjusting region, a gate electrode, an interlayer insulating film, a source electrode, and a drain electrode. The channel resistance adjusting region is sandwiched between the source region and the SiC epitaxial layer in a surface layer of the well region. The channel resistance adjusting region is a region in which a first impurity region is intermittently formed in a direction intersecting a direction in which the source region and the SiC epitaxial layer sandwich the channel resistance adjusting region.Type: GrantFiled: June 27, 2014Date of Patent: May 29, 2018Assignee: Mitsubishi Electric CorporationInventors: Yasushi Takaki, Yoichiro Tarui
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Patent number: 9935170Abstract: A silicon carbide semiconductor device can switch between an on-state and an off-state by controlling a channel region with an application of a gate voltage. The silicon carbide semiconductor device includes a silicon carbide layer, a gate insulating film, and a gate electrode. The silicon carbide layer includes a channel region. The gate insulating film covers the channel region. The gate electrode faces the channel region with the gate insulating film therebetween. The resistance of the channel region in the on-state takes a minimum value at a temperature of not less than 100° C. and not more than 150° C.Type: GrantFiled: November 6, 2014Date of Patent: April 3, 2018Assignee: Mitsubishi Electric CorporationInventors: Toshikazu Tanioka, Yoichiro Tarui, Masayuki Furuhashi
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Publication number: 20180019308Abstract: The present invention relates to a power semiconductor device which includes: a first conductivity-type silicon carbide semiconductor layer; a switching device which is formed on the silicon carbide semiconductor layer; a second conductivity-type electric field relaxation impurity region which is formed in a terminal portion of a formation region of the switching device and which relaxes an electric field of the terminal portion; and a first conductivity-type added region which is provided between second conductivity-type well regions of a plurality of unit cells that constitutes the switching device, and at least on an outer side of the electric field relaxation impurity region, and which has an impurity concentration higher than that in the silicon carbide semiconductor layer.Type: ApplicationFiled: March 18, 2015Publication date: January 18, 2018Applicant: Mitsubishi Electric CorporationInventors: Yoichiro TARUI, Toshikazu TANIOKA, Yasunori ORITSUKI
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Patent number: 9842906Abstract: A MOSFET cell of a semiconductor device includes a polysilicon gate electrode and an n+-source region formed in an upper portion of an n?-drift layer. An interlayer insulating film covers the gate electrode. An Al source electrode extends on the interlayer insulating film. An Al gate pad is connected to the gate electrode. A barrier metal layer that prevents diffusion of aluminum is interposed between the source electrode and the interlayer insulating film, and between the gate pad and the gate electrode.Type: GrantFiled: May 1, 2015Date of Patent: December 12, 2017Assignee: MITSUBISHI ELECTRIC CORPORATIONInventors: Eisuke Suekawa, Yasunori Oritsuki, Yoichiro Tarui
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Publication number: 20170250254Abstract: A silicon carbide semiconductor device can switch between an on-state and an off-state by controlling a channel region with an application of a gate voltage. The silicon carbide semiconductor device includes a silicon carbide layer, a gate insulating film, and a gate electrode. The silicon carbide layer includes a channel region. The gate insulating film covers the channel region. The gate electrode faces the channel region with the gate insulating film therebetween. The resistance of the channel region in the on-state takes a minimum value at a temperature of not less than 100° C. and not more than 150° C.Type: ApplicationFiled: November 6, 2014Publication date: August 31, 2017Applicant: Mitsubishi Electric CorporationInventors: Toshikazu TANIOKA, Yoichiro TARUI, Masayuki FURUHASHI
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Patent number: 9748393Abstract: It is an object of the present invention to provide a silicon carbide semiconductor device that reduces a channel resistance and increases reliability of a gate insulating film. The present invention includes a trench partially formed in a surface layer of an epitaxial layer, a well layer formed along side surfaces and a bottom surface of the trench, a source region formed in a surface layer of the well layer on the bottom surface of the trench, a gate insulating film, and a gate electrode. The gate insulating film is formed along the side surfaces of the trench and has one end formed so as to reach the source region. The gate electrode is formed along the side surfaces of the trench and formed on the gate insulating film.Type: GrantFiled: October 17, 2013Date of Patent: August 29, 2017Assignee: Mitsubishi Electric CorporationInventor: Yoichiro Tarui
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Patent number: 9627571Abstract: An optical fiber is provided between a photodiode and a semiconductor active portion of a wide gap semiconductor element forming portion such that emitted light at the time of light emission of the semiconductor active portion of the wide gap semiconductor element forming portion is incident from an incident surface of the optical fiber, and is received from an emitting surface to the photodiode through the optical fiber. Specifically, the incident surface of the optical fiber is arranged so as to be opposed to a side surface portion of the wide gap semiconductor element forming portion, so that the emitted light at the time of light emission of the wide gap semiconductor element is incident on the incident surface.Type: GrantFiled: March 24, 2014Date of Patent: April 18, 2017Assignee: Mitsubishi Electric CorporationInventors: Naoto Kaguchi, Yoichiro Tarui
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Publication number: 20170054017Abstract: The present invention can reduce an on-resistance while suppressing reduction in a short circuit capacity. The present invention includes a SiC epitaxial layer, a well region, a source region, a channel resistance adjusting region, a gate electrode, an interlayer insulating film, a source electrode, and a drain electrode. The channel resistance adjusting region is sandwiched between the source region and the SiC epitaxial layer in a surface layer of the well region. The channel resistance adjusting region is a region in which a first impurity region is intermittently formed in a direction intersecting a direction in which the source region and the SiC epitaxial layer sandwich the channel resistance adjusting region.Type: ApplicationFiled: June 27, 2014Publication date: February 23, 2017Applicant: Mitsubishi Electric CorporationInventors: Yasushi TAKAKI, Yoichiro TARUI
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Patent number: 9455197Abstract: When a gate insulating film is formed on a silicon carbide substrate, the silicon carbide substrate is first oxidized with an oxidation reactant gas to form the gate insulating film on the surface of the silicon carbide substrate. The silicon carbide substrate on which the gate insulating film has been formed is nitrided with a nitriding reactant gas. The oxidation and the nitriding are performed continuously in the same diffusion furnace while a temperature of 1200° C. to 1300° C. inclusive is maintained.Type: GrantFiled: September 14, 2015Date of Patent: September 27, 2016Assignee: Mitsubishi Electric CorporationInventors: Hideaki Yuki, Kazuo Kobayashi, Yoichiro Tarui
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Publication number: 20160225905Abstract: It is an object of the present invention to provide a silicon carbide semiconductor device that reduces a channel resistance and increases reliability of a gate insulating film. The present invention includes a trench partially formed in a surface layer of an epitaxial layer, a well layer formed along side surfaces and a bottom surface of the trench, a source region formed in a surface layer of the well layer on the bottom surface of the trench, a gate insulating film, and a gate electrode. The gate insulating film is formed along the side surfaces of the trench and has one end formed so as to reach the source region. The gate electrode is formed along the side surfaces of the trench and formed on the gate insulating film.Type: ApplicationFiled: October 17, 2013Publication date: August 4, 2016Applicant: Mitsubishi Electric CorporationInventor: Yoichiro TARUI