Patents by Inventor Kentaro Chikamatsu
Kentaro Chikamatsu 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: 11908927Abstract: A nitride semiconductor device 1 includes a first nitride semiconductor layer 13 that constitutes an electron transit layer, a second nitride semiconductor layer 14 that is formed on the first nitride semiconductor layer and constitutes an electron supply layer, a nitride semiconductor gate layer 15 that is disposed on the second nitride semiconductor layer, has a ridge portion 15A at least at a portion thereof, and contains an acceptor type impurity, a gate electrode 4 that is disposed at least on the ridge portion of the nitride semiconductor gate layer, a source electrode 3 that is disposed on the second nitride semiconductor layer and has a source principal electrode portion 3A parallel to the ridge portion, and a drain electrode 5 that is disposed on the second nitride semiconductor layer and has a drain principal electrode portion 5A parallel to the ridge portion.Type: GrantFiled: January 23, 2020Date of Patent: February 20, 2024Assignee: ROHM CO., LTD.Inventors: Hirotaka Otake, Shinya Takado, Kentaro Chikamatsu
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Patent number: 11901316Abstract: A semiconductor device includes a lead frame, a transistor, and an encapsulation resin. The lead frame includes a drain frame, a source frame, and a gate frame. The drain frame includes drain frame fingers. The source frame includes source frame fingers. The drain frame fingers and the source frame fingers are alternately arranged in a first direction and include overlapping portions as viewed from a first direction. In a region where each drain frame finger overlaps the source frame fingers as viewed in the first direction, at least either one of the drain frame fingers and the source frame fingers are not exposed from the back surface of the encapsulation resin.Type: GrantFiled: April 20, 2022Date of Patent: February 13, 2024Assignee: ROHM CO., LTD.Inventors: Kentaro Chikamatsu, Koshun Saito, Kenichi Yoshimochi
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Publication number: 20230387285Abstract: A nitride semiconductor device includes an electron transit layer, an electron supply layer, a gate layer, a gate electrode, an insulation layer covering the electron supply layer, the gate layer, and the gate electrode and including a first opening and a second opening, a source electrode, and a drain electrode. The source electrode includes a source field plate covering the insulation layer and including an end located between the second opening and the gate layer in plan view. The insulation layer includes a first insulation layer part and a second insulation layer part. The first insulation layer part is disposed on the electron supply layer in contact with the drain electrode and has a first thickness. The second insulation layer part is disposed on the gate electrode in contact with the source field plate and has a second thickness. The second thickness is greater than the first thickness.Type: ApplicationFiled: August 3, 2023Publication date: November 30, 2023Applicant: ROHM CO., LTD.Inventor: Kentaro CHIKAMATSU
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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: 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: 20230043312Abstract: A method for manufacturing nitride semiconductor device includes a second step of forming, on a gate layer material film, a gate electrode film that is a material film of a gate electrode, a third step of selectively etching the gate electrode film to form the gate electrode 22 of a ridge shape, and a fourth step of selectively etching the gate layer material film to form a semiconductor gate layer 21 of a ridge shape with the gate electrode 22 disposed at a width intermediate portion of a front surface thereof. The third step includes a first etching step for forming a first portion 22A from an upper end to a thickness direction intermediate portion of the gate electrode 22 and a second etching step being a step differing in etching condition from the first etching step and being for forming a remaining second portion 22B of the gate electrode.Type: ApplicationFiled: January 15, 2021Publication date: February 9, 2023Applicant: ROHM CO., LTD.Inventors: Hirotaka OTAKE, Kentaro CHIKAMATSU
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Publication number: 20230005840Abstract: A semiconductor chip includes a front surface and a back surface, a source pad, a drain pad and a gate pad on the front surface; a die pad under the semiconductor chip and bonded to the semiconductor chip; a source lead, electrically connected to the die pad; a drain lead and a gate lead, disposed on a periphery of the die pad; and a sealing resin. A plurality of vias for external connection are formed to connect to the source pad. A first subset of the plurality of vias for external connection is disposed along a first side of the source pad, and a second subset of the plurality of vias for external connection is disposed along a second side of the source pad, wherein the first and second sides are arranged adjacent to each other to form a first edge of the source pad.Type: ApplicationFiled: September 9, 2022Publication date: January 5, 2023Inventors: Hirotaka OTAKE, Kentaro CHIKAMATSU
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Publication number: 20220416072Abstract: There is provided a nitride semiconductor device that includes a first nitride semiconductor layer configured as an electron transit layer, a second nitride semiconductor layer formed on the first nitride semiconductor layer and configured as an electron supply layer, a ridge-shaped nitride semiconductor gate layer disposed on the second nitride semiconductor layer and including an acceptor-type impurity, and a gate electrode formed on the nitride semiconductor gate layer. The gate electrode includes a first metal film that is formed on the nitride semiconductor gate layer and is mainly made of Ti, and a second metal film that is formed on the first metal film and is made of TiN.Type: ApplicationFiled: August 31, 2022Publication date: December 29, 2022Inventors: Hirotaka OTAKE, Shinya TAKADO, Kentaro CHIKAMATSU
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Patent number: 11476197Abstract: The present invention provides a semiconductor device for reducing parasitic inductance. The semiconductor device of the present invention includes: a semiconductor chip, including a front surface and a hack surface, and including a source pad, a drain pad and a gate pad on the front surface; a die pad, disposed under the semiconductor chip and bonded to the hack surface of the semiconductor chip; a source lead, electrically connected to the die pad; a drain lead and a gate lead, disposed on a periphery of the die pad; and a sealing resin, sealing the semiconductor chip, the die pad and each of the leads. At least one via for external connection is formed in the semiconductor chip to connect to the source pad, and the via for external connection is disposed on a circumferential portion of the semiconductor chip in perspective view.Type: GrantFiled: June 8, 2020Date of Patent: October 18, 2022Assignee: ROHM CO., LTD.Inventors: Hirotaka Otake, Kentaro Chikamatsu
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Patent number: 11462635Abstract: There is provided a nitride semiconductor device that includes a first nitride semiconductor layer configured as an electron transit layer, a second nitride semiconductor layer formed on the first nitride semiconductor layer and configured as an electron supply layer, a ridge-shaped nitride semiconductor gate layer disposed on the second nitride semiconductor layer and including an acceptor-type impurity, and a gate electrode formed on the nitride semiconductor gate layer. The gate electrode includes a first metal film that is formed on the nitride semiconductor gate layer and is mainly made of Ti, and a second metal film that is formed on the first metal film and is made of TiN.Type: GrantFiled: November 29, 2019Date of Patent: October 4, 2022Assignee: ROHM CO., LTD.Inventors: Hirotaka Otake, Shinya Takado, Kentaro Chikamatsu
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Publication number: 20220246551Abstract: A semiconductor device includes a lead frame, a transistor, and an encapsulation resin. The lead frame includes a drain frame, a source frame, and a gate frame. The drain frame includes drain frame fingers. The source frame includes source frame fingers. The drain frame fingers and the source frame fingers are alternately arranged in a first direction and include overlapping portions as viewed from a first direction. In a region where each drain frame finger overlaps the source frame fingers as viewed in the first direction, at least either one of the drain frame fingers and the source frame fingers are not exposed from the back surface of the encapsulation resin.Type: ApplicationFiled: April 20, 2022Publication date: August 4, 2022Inventors: Kentaro CHIKAMATSU, Koshun SAITO, Kenichi YOSHIMOCHI
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Publication number: 20220209001Abstract: A nitride semiconductor device 1 includes a first nitride semiconductor layer 4 that constitutes an electron transit layer, a second nitride semiconductor layer 5 that is formed on the first nitride semiconductor layer and constitutes an electron supply layer, and a gate portion 20 that is formed on the second nitride semiconductor layer. The gate portion 20 includes a semiconductor gate layer 21 of a ridge shape that is formed on the second nitride semiconductor layer and is constituted of a nitride semiconductor containing an acceptor type impurity and a gate electrode 22 that is formed on the semiconductor gate layer. The semiconductor gate layer is constituted of a gate layer main body portion 211 that is formed on the second nitride semiconductor layer and an upper protruding portion 212 that is formed on a width intermediate portion of an upper surface of the gate layer main body portion, and the gate electrode is formed on a top surface of the upper protruding portion.Type: ApplicationFiled: March 6, 2020Publication date: June 30, 2022Inventors: Hirotaka OTAKE, Kentaro CHIKAMATSU, Shinya TAKADO, Kazuya NAGASE
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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: 20220181477Abstract: A nitride semiconductor device 1 includes a first nitride semiconductor layer 13 that constitutes an electron transit layer, a second nitride semiconductor layer 14 that is formed on the first nitride semiconductor layer and constitutes an electron supply layer, a nitride semiconductor gate layer 15 that is disposed on the second nitride semiconductor layer, has a ridge portion 15A at least at a portion thereof, and contains an acceptor type impurity, a gate electrode 4 that is disposed at least on the ridge portion of the nitride semiconductor gate layer, a source electrode 3 that is disposed on the second nitride semiconductor layer and has a source principal electrode portion 3A parallel to the ridge portion, and a drain electrode 5 that is disposed on the second nitride semiconductor layer and has a drain principal electrode portion 5A parallel to the ridge portion.Type: ApplicationFiled: January 23, 2020Publication date: June 9, 2022Inventors: Hirotaka OTAKE, Shinya TAKADO, Kentaro CHIKAMATSU
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Patent number: 11342290Abstract: A semiconductor device includes a lead frame, a transistor, and an encapsulation resin. The lead frame includes a drain frame, a source frame, and a gate frame. The drain frame includes drain frame fingers. The source frame includes source frame fingers. The drain frame fingers and the source frame fingers are alternately arranged in a first direction and include overlapping portions as viewed from a first direction. In a region where each drain frame finger overlaps the source frame fingers as viewed in the first direction, at least either one of the drain frame fingers and the source frame fingers are not exposed from the back surface of the encapsulation resin.Type: GrantFiled: February 3, 2020Date of Patent: May 24, 2022Assignee: ROHM CO., LTD.Inventors: Kentaro Chikamatsu, Koshun Saito, Kenichi Yoshimochi
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Publication number: 20220140122Abstract: A semiconductor device is provided with, a group-III nitride semiconductor layered structure that includes a heterojunction, an insulating layer which has a gate opening that reaches the group-III nitride semiconductor layered structure and which is disposed on the group-III nitride semiconductor layered structure, a gate insulating film that covers the bottom and the side of the gate opening, a gate electrode defined on the gate insulating film inside the gate opening, a source electrode and a drain electrode which are disposed to be spaced apart from the gate electrode so as to sandwich the gate electrode, a first conductive layer embedded in the insulating layer between the gate electrode and the drain electrode, and a second conductive layer that is embedded in the insulating layer above the first conductive layer in a region closer to the drain electrode side than the first conductive layer.Type: ApplicationFiled: January 14, 2022Publication date: May 5, 2022Inventor: Kentaro CHIKAMATSU
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Patent number: 11257938Abstract: A semiconductor device is provided with, a group-III nitride semiconductor layered structure that includes a heterojunction, an insulating layer which has a gate opening that reaches the group-III nitride semiconductor layered structure and which is disposed on the group-III nitride semiconductor layered structure, a gate insulating film that covers the bottom and the side of the gate opening, a gate electrode defined on the gate insulating film inside the gate opening, a source electrode and a drain electrode which are disposed to be spaced apart from the gate electrode so as to sandwich the gate electrode, a first conductive layer embedded in the insulating layer between the gate electrode and the drain electrode, and a second conductive layer that is embedded in the insulating layer above the first conductive layer in a region closer to the drain electrode side than the first conductive layer.Type: GrantFiled: May 27, 2020Date of Patent: February 22, 2022Assignee: ROHM CO., LTD.Inventor: Kentaro Chikamatsu
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Publication number: 20200395303Abstract: The present invention provides a semiconductor device for reducing parasitic inductance. The semiconductor device of the present invention includes: a semiconductor chip, including a front surface and a hack surface, and including a source pad. a drain pad and a gate pad on the front surface; a die pad, disposed under the semiconductor chip and bonded to the hack surface of the semiconductor chip; a source lead, electrically connected to the die pad; a drain lead and a gate lead, disposed on a periphery of the die pad; and a sealing resin, sealing the semiconductor chip, the die pad and each of the leads. At least one via for external connection is formed in the semiconductor chip to connect to the source pad, and the via for external connection is disposed on a circumferential portion of the semiconductor chip in perspective view.Type: ApplicationFiled: June 8, 2020Publication date: December 17, 2020Inventors: Hirotaka OTAKE, Kentaro CHIKAMATSU
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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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Publication number: 20200287034Abstract: A semiconductor device is provided with, a group-III nitride semiconductor layered structure that includes a heterojunction, an insulating layer which has a gate opening that reaches the group-III nitride semiconductor layered structure and which is disposed on the group-III nitride semiconductor layered structure, a gate insulating film that covers the bottom and the side of the gate opening, a gate electrode defined on the gate insulating film inside the gate opening, a source electrode and a drain electrode which are disposed to be spaced apart from the gate electrode so as to sandwich the gate electrode, a first conductive layer embedded in the insulating layer between the gate electrode and the drain electrode, and a second conductive layer that is embedded in the insulating layer above the first conductive layer in a region closer to the drain electrode side than the first conductive layer.Type: ApplicationFiled: May 27, 2020Publication date: September 10, 2020Inventor: Kentaro CHIKAMATSU