Patents by Inventor Nobuo Machida
Nobuo Machida 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: 11646382Abstract: A junction barrier Schottky diode device and a method for fabricating the same is disclosed. In the junction barrier Schottky device includes an N-type semiconductor layer, a plurality of first P-type doped areas, a plurality of second P-type doped areas, and a conductive metal layer. The first P-type doped areas and the second P-type doped are formed in the N-type semiconductor layer. The second P-type doped areas are self-alignedly formed above the first P-type doped areas. The spacing between every neighboring two of the second P-type doped areas is larger than the spacing between every neighboring two of the first P-type doped areas. The conductive metal layer, formed on the N-type semiconductor layer, covers the first P-type doped areas and the second P-type doped areas.Type: GrantFiled: May 11, 2021Date of Patent: May 9, 2023Assignee: TAIPEI ANJET CORPORATIONInventors: Nobuo Machida, Wen-Tsung Chang, Wen-Chin Wu
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Publication number: 20230077367Abstract: A drift layer is formed over a semiconductor substrate which is an SiC substrate. The drift layer includes first to third n-type semiconductor layers and a p-type impurity region. Herein, an impurity concentration of the second n-type semiconductor layer is higher than an impurity concentration of the first n-type semiconductor layer and an impurity concentration of the third n-type semiconductor layer. Also, in plan view, the second semiconductor layer located between the p-type impurity regions adjacent to each other overlaps with at least a part of a gate electrode formed in a trench.Type: ApplicationFiled: November 21, 2022Publication date: March 16, 2023Inventors: Yasuhiro OKAMOTO, Nobuo MACHIDA, Koichi ARAI, Kenichi HISADA, Yasunori YAMASHITA, Satoshi EGUCHI, Hironobu MIYAMOTO, Atsushi SAKAI, Katsumi EIKYU
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Publication number: 20230030874Abstract: A method for manufacturing a semiconductor element includes preparing a semiconductor wafer that includes a substrate including a Ga2O3-based semiconductor and an epitaxial layer including a Ga2O3-based semiconductor and located on the substrate, fixing the epitaxial layer side of the semiconductor wafer to a support substrate, thinning the substrate of the semiconductor wafer fixed to the support substrate, after the thinning of the substrate, forming an electrode on a lower surface of the substrate, bonding or forming a support metal layer on a lower surface of the electrode of the semiconductor wafer, and dicing the semiconductor wafer into individual pieces, thereby obtaining plural semiconductor elements each including the support metal layer. Thermal conductivity of the support metal layer is higher than thermal conductivity of the substrate.Type: ApplicationFiled: December 21, 2020Publication date: February 2, 2023Applicants: TAMURA CORPORATION, Novel Crystal Technology, Inc.Inventor: Nobuo MACHIDA
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Publication number: 20230034806Abstract: A semiconductor device includes a lead frame including a raised portion on a surface, and a semiconductor element that is face-down mounted on the lead frame and includes a substrate including a Ga2O3-based semiconductor, an epitaxial layer including a Ga2O3-based semiconductor and stacked on the substrate, a first electrode connected to a surface of the substrate on an opposite side to the epitaxial layer, and a second electrode connected to a surface of the epitaxial layer on an opposite side to the substrate and including a field plate portion at an outer peripheral portion. The semiconductor element is fixed onto the raised portion. An outer peripheral portion of the epitaxial layer, which is located on the outer side of the field plate portion, is located directly above a flat portion of the lead frame that is a portion at which the raised portion is not provided.Type: ApplicationFiled: December 21, 2020Publication date: February 2, 2023Applicants: TAMURA CORPORATION, Novel Crystal Technology, Inc.Inventors: Nobuo MACHIDA, Kohei SASAKI
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Publication number: 20230021015Abstract: A method for fabricating a junction barrier Schottky diode device is disclosed. The junction barrier Schottky device includes an N-type semiconductor layer, a plurality of first P-type doped areas, a plurality of second P-type doped areas, and a conductive metal layer. The first P-type doped areas and the second P-type doped are formed in the N-type semiconductor layer. The second P-type doped areas are self-alignedly formed above the first P-type doped areas. The spacing between every neighboring two of the second P-type doped areas is larger than the spacing between every neighboring two of the first P-type doped areas. The conductive metal layer, formed on the N-type semiconductor layer, covers the first P-type doped areas and the second P-type doped areas.Type: ApplicationFiled: September 19, 2022Publication date: January 19, 2023Inventors: Nobuo MACHIDA, Wen-Tsung CHANG, Wen-Chin Wu
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Publication number: 20220367731Abstract: A junction barrier Schottky diode device and a method for fabricating the same is disclosed. In the junction barrier Schottky device includes an N-type semiconductor layer, a plurality of first P-type doped areas, a plurality of second P-type doped areas, and a conductive metal layer. The first P-type doped areas and the second P-type doped are formed in the N-type semiconductor layer. The second P-type doped areas are self-alignedly formed above the first P-type doped areas. The spacing between every neighboring two of the second P-type doped areas is larger than the spacing between every neighboring two of the first P-type doped areas. The conductive metal layer, formed on the N-type semiconductor layer, covers the first P-type doped areas and the second P-type doped areas.Type: ApplicationFiled: May 11, 2021Publication date: November 17, 2022Inventors: Nobuo Machida, Wen-Tsung Chang, Wen-Chin Wu
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Patent number: 11489047Abstract: To improve an on-resistance of a semiconductor device. A plurality of collector regions are formed at a predetermined interval on a bottom surface of a drift layer made of SiC. Next, on the bottom surface of the drift layer, both of the drift layer and a collector region via a silicide layer are connected to a collector electrode.Type: GrantFiled: October 12, 2020Date of Patent: November 1, 2022Assignee: RENESAS ELECTRONICS CORPORATIONInventors: Yasuhiro Okamoto, Nobuo Machida
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Patent number: 11276784Abstract: In a Schottky barrier diode region, a Schottky barrier diode is formed between an n-type drift layer and a metal layer, and in a body diode region, a p-type semiconductor region, a p-type semiconductor region, and a p-type semiconductor region are formed in order from a main surface side in the drift layer, and a body diode is formed between the p-type semiconductor region and the drift layer. An impurity concentration of the p-type semiconductor region is decreased lower than the impurity concentration of the p-type semiconductor regions, thereby increasing the reflux current flowing through the Schottky barrier diode and preventing the reflux current from flowing through the body diode.Type: GrantFiled: December 14, 2020Date of Patent: March 15, 2022Assignee: RENESAS ELECTRONICS CORPORATIONInventors: Yasuhiro Okamoto, Nobuo Machida, Kenichi Hisada
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Publication number: 20210217888Abstract: To improve characteristics of a semiconductor device. A first p-type semiconductor region having an impurity of a conductivity type opposite from that of a drift layer is arranged in the drift layer below a trench, and a second p-type semiconductor region is further arranged that is spaced at a distance from a region where the trench is formed as seen from above and that has the impurity of the conductivity type opposite from that of the drift layer. The second p-type semiconductor region is configured by a plurality of regions arranged at a space in a Y direction (depth direction in the drawings). Thus, it is possible to reduce the specific on-resistance while maintaining the breakdown voltage of the gate insulating film by providing the first and second p-type semiconductor regions and further by arranging the second p-type semiconductor region spaced by the space.Type: ApplicationFiled: March 29, 2021Publication date: July 15, 2021Inventors: Atsushi SAKAI, Katsumi EIKYU, Satoshi EGUCHI, Nobuo MACHIDA, Koichi ARAI, Yasuhiro OKAMOTO, Kenichi HISADA, Yasunori YAMASHITA
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Publication number: 20210159315Abstract: To improve an on-resistance of a semiconductor device. A plurality of collector regions are formed at a predetermined interval on a bottom surface of a drift layer made of SiC. Next, on the bottom surface of the drift layer, both of the drift layer and a collector region via a silicide layer are connected to a collector electrode.Type: ApplicationFiled: October 12, 2020Publication date: May 27, 2021Inventors: Yasuhiro OKAMOTO, Nobuo MACHIDA
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Publication number: 20210135018Abstract: In a Schottky barrier diode region, a Schottky barrier diode is formed between an n-type drift layer and a metal layer, and in a body diode region, a p-type semiconductor region, a p-type semiconductor region, and a p-type semiconductor region are formed in order from a main surface side in the drift layer, and a body diode is formed between the p-type semiconductor region and the drift layer. An impurity concentration of the p-type semiconductor region is decreased lower than the impurity concentration of the p-type semiconductor regions, thereby increasing the reflux current flowing through the Schottky barrier diode and preventing the reflux current from flowing through the body diode.Type: ApplicationFiled: December 14, 2020Publication date: May 6, 2021Inventors: Yasuhiro OKAMOTO, Nobuo MACHIDA, Kenichi HISADA
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Publication number: 20210074816Abstract: Semiconductor device has a cell region and a peripheral region, and has a drift layer, a trench, an gate dielectric film on an inner wall of the trench, a gate electrode, and a p-type first semiconductor region below the trench in the cell region on a semiconductor substrate. Further, in the peripheral region on the semiconductor substrate, p-type second semiconductor region is formed in the same layer as the p-type first semiconductor region. a width of the p-type first semiconductor region and a width of the p-type second semiconductor region are different.Type: ApplicationFiled: August 18, 2020Publication date: March 11, 2021Inventors: Atsushi SAKAI, Katsumi EIKYU, Yasuhiro OKAMOTO, Kenichi HISADA, Nobuo MACHIDA
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Patent number: 10896980Abstract: In a Schottky barrier diode region, a Schottky barrier diode is formed between an n-type drift layer and a metal layer, and in a body diode region, a p-type semiconductor region, a p-type semiconductor region, and a p-type semiconductor region are formed in order from a main surface side in the drift layer, and a body diode is formed between the p-type semiconductor region and the drift layer. An impurity concentration of the p-type semiconductor region is decreased lower than the impurity concentration of the p-type semiconductor regions, thereby increasing the reflux current flowing through the Schottky barrier diode and preventing the reflux current from flowing through the body diode.Type: GrantFiled: October 10, 2019Date of Patent: January 19, 2021Assignee: RENESAS ELECTRONICS CORPORATIONInventors: Yasuhiro Okamoto, Nobuo Machida, Kenichi Hisada
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Publication number: 20200161445Abstract: An n-type epitaxial layer is formed on an n-type semiconductor substrate made of silicon carbide. p-type body regions are formed in the epitaxial layer, and n-type source region is formed in the body region. On the body region between the source region and the epitaxial layer, a gate electrode is formed via a gate dielectric film, and an interlayer insulating film having an opening is formed so as to cover the gate electrode. A source electrode electrically connected to the source region and the body regions is formed in the opening. A recombination layer is formed between the body region and a basal plane dislocation is a layer having point defect density higher than that of the epitaxial layer located directly under the recombination layer or having a metal added to the epitaxial layer.Type: ApplicationFiled: October 9, 2019Publication date: May 21, 2020Inventors: Hironobu MIYAMOTO, Yasuhiro OKAMOTO, Kenichi HISADA, Koichi ARAI, Nobuo MACHIDA
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Publication number: 20200161480Abstract: In a Schottky barrier diode region, a Schottky barrier diode is formed between an n-type drift layer and a metal layer, and in a body diode region, a p-type semiconductor region, a p-type semiconductor region, and a p-type semiconductor region are formed in order from a main surface side in the drift layer, and a body diode is formed between the p-type semiconductor region and the drift layer. An impurity concentration of the p-type semiconductor region is decreased lower than the impurity concentration of the p-type semiconductor regions, thereby increasing the reflux current flowing through the Schottky barrier diode and preventing the reflux current from flowing through the body diode.Type: ApplicationFiled: October 10, 2019Publication date: May 21, 2020Inventors: Yasuhiro OKAMOTO, Nobuo MACHIDA, Kenichi HISADA
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Publication number: 20190237577Abstract: A drift layer is formed over a semiconductor substrate which is an SiC substrate. The drift layer includes first to third n-type semiconductor layers and a p-type impurity region. Herein, an impurity concentration of the second n-type semiconductor layer is higher than an impurity concentration of the first n-type semiconductor layer and an impurity concentration of the third n-type semiconductor layer. Also, in plan view, the second semiconductor layer located between the p-type impurity regions adjacent to each other overlaps with at least a part of a gate electrode formed in a trench.Type: ApplicationFiled: December 18, 2018Publication date: August 1, 2019Inventors: Yasuhiro OKAMOTO, Nobuo MACHIDA, Koichi ARAI, Kenichi HISADA, Yasunori YAMASHITA, Satoshi EGUCHI, Hironobu MIYAMOTO, Atsushi SAKAI, Katsumi EIKYU
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Publication number: 20190198663Abstract: To improve characteristics of a semiconductor device. A first p-type semiconductor region having an impurity of a conductivity type opposite from that of a drift layer is arranged in the drift layer below a trench, and a second p-type semiconductor region is further arranged that is spaced at a distance from a region where the trench is formed as seen from above and that has the impurity of the conductivity type opposite from that of the drift layer. The second p-type semiconductor region is configured by a plurality of regions arranged at a space in a Y direction (depth direction in the drawings). Thus, it is possible to reduce the specific on-resistance while maintaining the breakdown voltage of the gate insulating film by providing the first and second p-type semiconductor regions and further by arranging the second p-type semiconductor region spaced by the space.Type: ApplicationFiled: November 15, 2018Publication date: June 27, 2019Inventors: Atsushi SAKAI, Katsumi EIKYU, Satoshi EGUCHI, Nobuo MACHIDA, Koichi ARAI, Yasuhiro OKAMOTO, Kenichi HISADA, Yasunori YAMASHITA
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Patent number: 9793342Abstract: In an insulated-gate type semiconductor device in which a gate-purpose conductive layer is embedded into a trench which is formed in a semiconductor substrate, and a source-purpose conductive layer is provided on a major surface of the semiconductor substrate, a portion of a gate pillar which is constituted by both the gate-purpose conductive layer and a cap insulating film for capping an upper surface of the gate-purpose conductive layer is projected from the major surface of the semiconductor substrate; a side wall spacer is provided on a side wall of the projected portion of the gate pillar; and the source-purpose conductive layer is connected to a contact region of the major surface of the semiconductor substrate, which is defined by the side wall spacer.Type: GrantFiled: December 21, 2015Date of Patent: October 17, 2017Assignees: Renesas Electronics Corporation, Renesas Semiconductor Package & Test Solutions Co., LtdInventors: Hiroshi Inagawa, Nobuo Machida, Kentaro Oishi
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Patent number: 9614055Abstract: A semiconductor device has an FET of a trench-gate structure obtained by disposing a conductive layer, which will be a gate, in a trench extended in the main surface of a semiconductor substrate, wherein the upper surface of the trench-gate conductive layer is formed equal to or higher than the main surface of the semiconductor substrate. The conductive layer of the trench gate is formed to have a substantially flat or concave upper surface and the upper surface is formed equal to or higher than the main surface of the semiconductor substrate. After etching of the semiconductor substrate to form the upper surface of the conductive layer of the trench gate, a channel region and a source region are formed by ion implantation so that the semiconductor device is free from occurrence of a source offset.Type: GrantFiled: February 18, 2015Date of Patent: April 4, 2017Assignee: RENESAS ELECTRONICS CORPORATIONInventors: Hiroshi Inagawa, Nobuo Machida, Kentaro Ooishi
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Patent number: 9543395Abstract: In general, in a semiconductor active element such as a normally-off JFET based on SiC in which an impurity diffusion speed is significantly lower than in silicon, gate regions are formed through ion implantation into the side walls of trenches formed in source regions. However, to ensure the performance of the JFET, it is necessary to control the area between the gate regions thereof with high precision. Besides, there is such a problem that, since a heavily doped PN junction is formed by forming the gate regions in the source regions, an increase in junction current cannot be avoided. The present invention provides a normally-off power JFET and a manufacturing method thereof and forms the gate regions according to a multi-epitaxial method which repeats a process including epitaxial growth, ion implantation, and activation annealing a plurality of times.Type: GrantFiled: November 9, 2014Date of Patent: January 10, 2017Assignee: Renesas Electronics CorporationInventors: Koichi Arai, Yasuaki Kagotoshi, Nobuo Machida, Natsuki Yokoyama, Haruka Shimizu