Patents by Inventor Minoru Akutsu
Minoru Akutsu 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: 20230411508Abstract: A nitride semiconductor device includes an electron transit layer that is formed of a nitride semiconductor, an electron supply layer that is formed on the electron transit layer, and formed of a nitride semiconductor and that has a recess which reaches the electron transit layer from a surface, a thermal oxide film that is formed on the surface of the electron transit layer exposed within the recess, a gate insulating film that is embedded within the recess so as to be in contact with the thermal oxide film, a gate electrode that is formed on the gate insulating film and that is opposite to the electron transit layer across the thermal oxide film and the gate insulating film, and a source electrode and a drain electrode that are provided on the electron supply layer at an interval such that the gate electrode intervenes therebetween.Type: ApplicationFiled: August 18, 2023Publication date: December 21, 2023Applicant: ROHM CO., LTD.Inventors: Kenji YAMAMOTO, Tetsuya FUJIWARA, Minoru AKUTSU, Ken NAKAHARA, Norikazu ITO
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Publication number: 20230326846Abstract: A semiconductor device 1 has an electrode structure that includes source electrodes 3, a gate electrode 4, and drain electrodes 5 disposed on a semiconductor laminated structure 2 and extending in parallel to each other and in a predetermined first direction and a wiring structure that includes source wirings 9, drain wirings 10, and gate wirings 11 disposed on the electrode structure and extending in parallel to each other and in a second direction orthogonal to the first direction. The source wirings 9, the drain wirings 10, and the gate wirings 11 are electrically connected to the source electrodes 3, the drain electrodes 5, and the gate electrode 4, respectively. The semiconductor device 1 includes a conductive film 8 disposed between the gate electrode 4 and the drain wirings 10 and being electrically connected to the source electrodes 3.Type: ApplicationFiled: May 16, 2023Publication date: October 12, 2023Inventors: Minoru AKUTSU, Kentaro CHIKAMATSU
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Patent number: 11777024Abstract: A nitride semiconductor device includes an electron transit layer (103) that is formed of a nitride semiconductor, an electron supply layer (104) that is formed on the electron transit layer (103), that is formed of a nitride semiconductor whose composition is different from the electron transit layer (103) and that has a recess (109) which reaches the electron transit layer (103) from a surface, a thermal oxide film (111) that is formed on the surface of the electron transit layer (103) exposed within the recess (109), a gate insulating film (110) that is embedded within the recess (109) so as to be in contact with the thermal oxide film (111), a gate electrode (108) that is formed on the gate insulating film (110) and that is opposite to the electron transit layer (103) across the thermal oxide film (111) and the gate insulating film (110), and a source electrode (106) and a drain electrode (107) that are provided on the electron supply layer (104) at an interval such that the gate electrode (108) interveneType: GrantFiled: March 25, 2021Date of Patent: October 3, 2023Assignee: ROHM CO., LTD.Inventors: Kenji Yamamoto, Tetsuya Fujiwara, Minoru Akutsu, Ken Nakahara, Norikazu Ito
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Patent number: 11694954Abstract: A semiconductor device 1 has an electrode structure that includes source electrodes 3, a gate electrode 4, and drain electrodes 5 disposed on a semiconductor laminated structure 2 and extending in parallel to each other and in a predetermined first direction and a wiring structure that includes source wirings 9, drain wirings 10, and gate wirings 11 disposed on the electrode structure and extending in parallel to each other and in a second direction orthogonal to the first direction. The source wirings 9, the drain wirings 10, and the gate wirings 11 are electrically connected to the source electrodes 3, the drain electrodes 5, and the gate electrode 4, respectively. The semiconductor device 1 includes a conductive film 8 disposed between the gate electrode 4 and the drain wirings 10 and being electrically connected to the source electrodes 3.Type: GrantFiled: December 5, 2018Date of Patent: July 4, 2023Assignee: ROHM CO., LTD.Inventors: Minoru Akutsu, Kentaro Chikamatsu
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Publication number: 20220319964Abstract: A semiconductor device includes a semiconductor element, a first lead, a second lead and a connection lead. The semiconductor element includes an electron transit layer formed of a nitride semiconductor, an element obverse face and an element reverse face that are arranged to face opposite to each other in a thickness direction, and a gate electrode, a source electrode and a drain electrode that are disposed on the element obverse face. The drain electrode is bonded to the first lead. The source electrode is bonded to the second lead. The connection lead is connected to the second lead and disposed on the element reverse face so as to overlap with the semiconductor element as viewed in the thickness direction. The connection lead provides a conduction path for a principal current subjected to switching.Type: ApplicationFiled: June 19, 2020Publication date: October 6, 2022Inventor: Minoru AKUTSU
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Publication number: 20220199820Abstract: A nitride semiconductor device 1 includes a first nitride semiconductor layer that constitutes an electron transit layer, a second nitride semiconductor layer that is formed on the first nitride semiconductor layer, is larger in bandgap than the first nitride semiconductor layer, and constitutes an electron supply layer, a gate portion that is formed on the second nitride semiconductor layer, and a source electrode and a drain electrode that, on the second nitride semiconductor layer, are opposingly disposed across the gate portion. The gate portion includes a third nitride semiconductor layer of a ridge shape that is formed on the second nitride semiconductor layer and contains an acceptor type impurity and a gate electrode that is formed on the third nitride semiconductor layer. A film thickness of the third nitride semiconductor layer is greater than 100 nm.Type: ApplicationFiled: March 6, 2020Publication date: June 23, 2022Inventors: Hirotaka OTAKE, Kentaro CHIKAMATSU, Minoru AKUTSU, Shinya TAKADO
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Publication number: 20210376136Abstract: The present disclosure provides a nitride semiconductor device capable of reducing the ohmic contact resistance of a source electrode and a drain electrode with respect to a two-dimensional electron gas. The nitride semiconductor device includes: a first nitride semiconductor layer configured as an electron transportation layer, a second nitride semiconductor layer formed on the first nitride semiconductor layer and configured as an electron supply layer, an etch stop layer formed on the second nitride semiconductor layer and formed by a nitride semiconductor material having a bandgap greater than that of the second nitride semiconductor layer, a gate formed on the etch stop layer; and a source electrode and a drain electrode, disposed above the etch stop layer on opposite sides, wherein the gate is between the source electrode and the drain electrode.Type: ApplicationFiled: May 24, 2021Publication date: December 2, 2021Inventor: MINORU AKUTSU
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Publication number: 20210217886Abstract: A nitride semiconductor device includes an electron transit layer (103) that is formed of a nitride semiconductor, an electron supply layer (104) that is formed on the electron transit layer (103), that is formed of a nitride semiconductor whose composition is different from the electron transit layer (103) and that has a recess (109) which reaches the electron transit layer (103) from a surface, a thermal oxide film (111) that is formed on the surface of the electron transit layer (103) exposed within the recess (109), a gate insulating film (110) that is embedded within the recess (109) so as to be in contact with the thermal oxide film (111), a gate electrode (108) that is formed on the gate insulating film (110) and that is opposite to the electron transit layer (103) across the thermal oxide film (111) and the gate insulating film (110), and a source electrode (106) and a drain electrode (107) that are provided on the electron supply layer (104) at an interval such that the gate electrode (108) interveneType: ApplicationFiled: March 25, 2021Publication date: July 15, 2021Inventors: Kenji YAMAMOTO, Tetsuya FUJIWARA, Minoru AKUTSU, Ken NAKAHARA, Norikazu ITO
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Patent number: 10991818Abstract: A nitride semiconductor device includes an electron transit layer (103) that is formed of a nitride semiconductor, an electron supply layer (104) that is formed on the electron transit layer (103), that is formed of a nitride semiconductor whose composition is different from the electron transit layer (103) and that has a recess (109) which reaches the electron transit layer (103) from a surface, a thermal oxide film (111) that is formed on the surface of the electron transit layer (103) exposed within the recess (109), a gate insulating film (110) that is embedded within the recess (109) so as to be in contact with the thermal oxide film (111), a gate electrode (108) that is formed on the gate insulating film (110) and that is opposite to the electron transit layer (103) across the thermal oxide film (111) and the gate insulating film (110), and a source electrode (106) and a drain electrode (107) that are provided on the electron supply layer (104) at an interval such that the gate electrode (108) interveneType: GrantFiled: May 12, 2020Date of Patent: April 27, 2021Assignee: ROHM CO., LTD.Inventors: Kenji Yamamoto, Tetsuya Fujiwara, Minoru Akutsu, Ken Nakahara, Norikazu Ito
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Publication number: 20200357736Abstract: A semiconductor device 1 has an electrode structure that includes source electrodes 3, a gate electrode 4, and drain electrodes 5 disposed on a semiconductor laminated structure 2 and extending in parallel to each other and in a predetermined first direction and a wiring structure that includes source wirings 9, drain wirings 10, and gate wirings 11 disposed on the electrode structure and extending in parallel to each other and in a second direction orthogonal to the first direction. The source wirings 9, the drain wirings 10, and the gate wirings 11 are electrically connected to the source electrodes 3, the drain electrodes 5, and the gate electrode 4, respectively. The semiconductor device 1 includes a conductive film 8 disposed between the gate electrode 4 and the drain wirings 10 and being electrically connected to the source electrodes 3.Type: ApplicationFiled: December 5, 2018Publication date: November 12, 2020Inventors: Minoru AKUTSU, Kentaro CHIKAMATSU
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Patent number: 10804384Abstract: A semiconductor device includes: a back barrier layer containing AlXGa(1-X)N (0<X?1); an electron transit layer containing AlaInbGa(1-a-b)N (0?a+b?1) and formed on the back barrier layer; a top barrier layer containing AlYGa(1-Y)N (0<Y?1) and formed on the electron transit layer; an electron supply layer containing AlZGa(1-Z)N (0<Z?1) and formed on the top barrier layer, the electron supply layer having an opening to expose the top barrier layer; a two-dimensional electron gas region formed in an area of a surface layer portion of the electron transit layer, the area opposing the electron supply layer with the top barrier layer interposed between the electron supply layer and the area; a gate insulating layer formed in the opening of the electron supply layer; and a gate electrode layer formed on the gate insulating layer and opposing the electron transit layer with the gate insulating layer interposed therebetween.Type: GrantFiled: December 26, 2018Date of Patent: October 13, 2020Assignee: ROHM CO., LTD.Inventors: Kazuya Nagase, Shinya Takado, Minoru Akutsu
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Publication number: 20200273975Abstract: A nitride semiconductor device includes an electron transit layer (103) that is formed of a nitride semiconductor, an electron supply layer (104) that is formed on the electron transit layer (103), that is formed of a nitride semiconductor whose composition is different from the electron transit layer (103) and that has a recess (109) which reaches the electron transit layer (103) from a surface, a thermal oxide film (111) that is formed on the surface of the electron transit layer (103) exposed within the recess (109), a gate insulating film (110) that is embedded within the recess (109) so as to be in contact with the thermal oxide film (111), a gate electrode (108) that is formed on the gate insulating film (110) and that is opposite to the electron transit layer (103) across the thermal oxide film (111) and the gate insulating film (110), and a source electrode (106) and a drain electrode (107) that are provided on the electron supply layer (104) at an interval such that the gate electrode (108) interveneType: ApplicationFiled: May 12, 2020Publication date: August 27, 2020Inventors: Kenji YAMAMOTO, Tetsuya FUJIWARA, Minoru AKUTSU, Ken NAKAHARA, Norikazu ITO
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Patent number: 10727312Abstract: A nitride semiconductor device includes: an electron transit layer including GaxIn1-xN (0<x?1); an electron supply layer formed on the electron transit layer and including AlyIn1-yN (0<y?1); a gate insulating film formed to pass through the electron supply layer to contact the electron transit layer; and a gate electrode facing the electron transit layer with the gate insulating film interposed therebetween, wherein, in the electron transit layer, a portion contacting the gate insulating film and a portion contacting the electron transit layer are flush with each other.Type: GrantFiled: May 23, 2019Date of Patent: July 28, 2020Assignee: ROHM CO., LTD.Inventors: Shinya Takado, Minoru Akutsu, Taketoshi Tanaka, Norikazu Ito
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Patent number: 10686064Abstract: A nitride semiconductor device includes an electron transit layer (103) that is formed of a nitride semiconductor, an electron supply layer (104) that is formed on the electron transit layer (103), that is formed of a nitride semiconductor whose composition is different from the electron transit layer (103) and that has a recess (109) which reaches the electron transit layer (103) from a surface, a thermal oxide film (111) that is formed on the surface of the electron transit layer (103) exposed within the recess (109), a gate insulating film (110) that is embedded within the recess (109) so as to be in contact with the thermal oxide film (111), a gate electrode (108) that is formed on the gate insulating film (110) and that is opposite to the electron transit layer (103) across the thermal oxide film (111) and the gate insulating film (110), and a source electrode (106) and a drain electrode (107) that are provided on the electron supply layer (104) at an interval such that the gate electrode (108) interveneType: GrantFiled: March 7, 2019Date of Patent: June 16, 2020Assignee: ROHM CO., LTD.Inventors: Kenji Yamamoto, Tetsuya Fujiwara, Minoru Akutsu, Ken Nakahara, Norikazu Ito
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Publication number: 20190280101Abstract: A nitride semiconductor device includes: an electron transit layer including GaxIn1-xN (0<x?1); an electron supply layer formed on the electron transit layer and including AlyIn1-yN (0<y?1); a gate insulating film formed to pass through the electron supply layer to contact the electron transit layer; and a gate electrode facing the electron transit layer with the gate insulating film interposed therebetween, wherein, in the electron transit layer, a portion contacting the gate insulating film and a portion contacting the electron transit layer are flush with each other.Type: ApplicationFiled: May 23, 2019Publication date: September 12, 2019Applicant: ROHM CO., LTD.Inventors: Shinya TAKADO, Minoru AKUTSU, Taketoshi TANAKA, Norikazu ITO
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Publication number: 20190207023Abstract: A nitride semiconductor device includes an electron transit layer (103) that is formed of a nitride semiconductor, an electron supply layer (104) that is formed on the electron transit layer (103), that is formed of a nitride semiconductor whose composition is different from the electron transit layer (103) and that has a recess (109) which reaches the electron transit layer (103) from a surface, a thermal oxide film (111) that is formed on the surface of the electron transit layer (103) exposed within the recess (109), a gate insulating film (110) that is embedded within the recess (109) so as to be in contact with the thermal oxide film (111), a gate electrode (108) that is formed on the gate insulating film (110) and that is opposite to the electron transit layer (103) across the thermal oxide film (111) and the gate insulating film (110), and a source electrode (106) and a drain electrode (107) that are provided on the electron supply layer (104) at an interval such that the gate electrode (108) interveneType: ApplicationFiled: March 7, 2019Publication date: July 4, 2019Inventors: Kenji YAMAMOTO, Tetsuya FUJIWARA, Minoru AKUTSU, Ken NAKAHARA, Norikazu ITO
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Publication number: 20190207022Abstract: A semiconductor device includes: a back barrier layer containing AlXGa(1-X)N (0<X?1); an electron transit layer containing AlaInbGa(1-a-b)N (0?a+b?1) and formed on the back barrier layer; a top barrier layer containing AlYGa(1-Y)N (0<Y?1) and formed on the electron transit layer; an electron supply layer containing AlZGa(1-Z)N (0<Z?1) and formed on the top barrier layer, the electron supply layer having an opening to expose the top barrier layer; a two-dimensional electron gas region formed in an area of a surface layer portion of the electron transit layer, the area opposing the electron supply layer with the top barrier layer interposed between the electron supply layer and the area; a gate insulating layer formed in the opening of the electron supply layer; and a gate electrode layer formed on the gate insulating layer and opposing the electron transit layer with the gate insulating layer interposed therebetween.Type: ApplicationFiled: December 26, 2018Publication date: July 4, 2019Inventors: Kazuya NAGASE, Shinya TAKADO, Minoru AKUTSU
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Patent number: 10340360Abstract: A nitride semiconductor device includes: an electron transit layer including GaxIn1-xN (0<x?1); an electron supply layer formed on the electron transit layer and including AlyIn1-yN (0<y?1); a gate insulating film formed to pass through the electron supply layer to contact the electron transit layer; and a gate electrode facing the electron transit layer with the gate insulating film interposed therebetween, wherein, in the electron transit layer, a portion contacting the gate insulating film and a portion contacting the electron transit layer are flush with each other.Type: GrantFiled: February 26, 2018Date of Patent: July 2, 2019Assignee: ROHM CO., LTD.Inventors: Shinya Takado, Minoru Akutsu, Taketoshi Tanaka, Norikazu Ito
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Patent number: 10256335Abstract: A nitride semiconductor device includes an electron transit layer (103) that is formed of a nitride semiconductor, an electron supply layer (104) that is formed on the electron transit layer (103), that is formed of a nitride semiconductor whose composition is different from the electron transit layer (103) and that has a recess (109) which reaches the electron transit layer (103) from a surface, a thermal oxide film (111) that is formed on the surface of the electron transit layer (103) exposed within the recess (109), a gate insulating film (110) that is embedded within the recess (109) so as to be in contact with the thermal oxide film (111), a gate electrode (108) that is formed on the gate insulating film (110) and that is opposite to the electron transit layer (103) across the thermal oxide film (111) and the gate insulating film (110), and a source electrode (106) and a drain electrode (107) that are provided on the electron supply layer (104) at an interval such that the gate electrode (108) interveneType: GrantFiled: August 8, 2017Date of Patent: April 9, 2019Assignee: ROHM CO., LTD.Inventors: Kenji Yamamoto, Tetsuya Fujiwara, Minoru Akutsu, Ken Nakahara, Norikazu Ito
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Patent number: 10038070Abstract: A nitride semiconductor device according to the present invention includes a nitride semiconductor layer including an electron transit layer and an electron supply layer which is in contact with the electron transit layer and which has a composition different from that of the electron transit layer, a gate electrode on the nitride semiconductor layer and a gate insulating film between the gate electrode and the nitride semiconductor layer. A region whose depth is 250 nm from an interface between the gate insulating film and the gate electrode includes a region which has a deep acceptor concentration equal to or more than 1.0×1016 cm?3.Type: GrantFiled: August 9, 2016Date of Patent: July 31, 2018Assignee: ROHM CO., LTD.Inventors: Taketoshi Tanaka, Minoru Akutsu, Norikazu Ito