Patents by Inventor Mizue Kitada
Mizue Kitada 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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Method of manufacturing MOSFET having a semiconductor base substrate with a super junction structure
Patent number: 11843048Abstract: A MOSFET includes: a semiconductor base substrate having an n-type column region and a p-type column region, the n-type column region and the p-type column region forming a super junction structure; and a gate electrode formed by way of a gate insulation film. Assuming a region of the semiconductor base substrate which provides a main operation of the MOSFET as an active region, a region of the semiconductor base substrate maintaining a withstand voltage of the MOSFET as an outer peripheral region, and a region of the semiconductor base substrate disposed between the active region and the outer peripheral region as an active connecting region, out of the active region, the active connecting region, and the outer peripheral region of the semiconductor base substrate, the crystal defects are formed only in the active region and the active connecting region.Type: GrantFiled: April 22, 2022Date of Patent: December 12, 2023Assignee: SHINDENGEN ELECTRIC MANUFACTURING CO., LTD.Inventors: Daisuke Arai, Mizue Kitada, Takeshi Asada, Noriaki Suzuki, Koichi Murakami -
Patent number: 11626479Abstract: A semiconductor device includes: a semiconductor base substrate including a semiconductor layer; a first main electrode; a second main electrode; a plurality of peripheral trenches formed on a surface of the semiconductor layer and having bottom portions covered by the semiconductor layer in a peripheral region; and a plurality of in-trench electrodes each embedded in each of the plurality of peripheral trenches byway of an insulation layer formed on an inner surface of the each peripheral trench, wherein the semiconductor base substrate further includes, in the peripheral region, a plurality of second conductive type floating regions disposed in the semiconductor layer at a depth position deeper than the bottom portions of the peripheral trenches in a spaced apart manner from the peripheral trenches and having a potential in a floating state.Type: GrantFiled: June 4, 2020Date of Patent: April 11, 2023Assignee: SHINDENGEN ELECTRIC MANUFACTURING CO., LTD.Inventors: Gotaro Takemoto, Toshihiro Okuda, Mizue Kitada
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Publication number: 20220246755Abstract: A MOSFET includes: a semiconductor base substrate having an n-type column region and a p-type column region, the n-type column region and the p-type column region forming a super junction structure; and a gate electrode formed by way of a gate insulation film. Assuming a region of the semiconductor base substrate which provides a main operation of the MOSFET as an active region, a region of the semiconductor base substrate maintaining a withstand voltage of the MOSFET as an outer peripheral region, and a region of the semiconductor base substrate disposed between the active region and the outer peripheral region as an active connecting region, out of the active region, the active connecting region, and the outer peripheral region of the semiconductor base substrate, the crystal defects are formed only in the active region and the active connecting region.Type: ApplicationFiled: April 22, 2022Publication date: August 4, 2022Inventors: Daisuke ARAI, Mizue KITADA, Takeshi ASADA, Noriaki SUZUKI, Koichi MURAKAMI
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Patent number: 11342452Abstract: A MOSFET includes: a semiconductor base substrate having an n-type column region and a p-type column region, the n-type column region and the p-type column region forming a super junction structure; and a gate electrode formed by way of a gate insulation film. Assuming a region of the semiconductor base substrate which provides a main operation of the MOSFET as an active region, a region of the semiconductor base substrate maintaining a withstand voltage of the MOSFET as an outer peripheral region, and a region of the semiconductor base substrate disposed between the active region and the outer peripheral region as an active connecting region, out of the active region, the active connecting region, and the outer peripheral region of the semiconductor base substrate, the crystal defects are formed only in the active region and the active connecting region.Type: GrantFiled: December 27, 2017Date of Patent: May 24, 2022Assignee: SHINDENGEN ELECTRIC MANUFACTURING CO., LTD.Inventors: Daisuke Arai, Mizue Kitada, Takeshi Asada, Noriaki Suzuki, Koichi Murakami
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Patent number: 11005354Abstract: A power conversion circuit includes: a MOSFET having a super junction structure; an inductive load; and a freewheel diode. A switching frequency of the MOSFET is 10 kHz or more. When the MOSFET is turned off, a first period during which a drain current decreases, a second period during which the drain current increases, and a third period during which the drain current decreases again appear in this order. The freewheel diode is an Si-FRD or an SiC-SBD, and current density obtained by dividing a current value of the forward current by an area of an active region of the freewheel diode falls within a range of 200 A/cm2 to 400 A/cm2 when the freewheel diode is the Si-FRD, and the current density falls within a range of 400 A/cm2 to 1500 A/cm2 when the freewheel diode is the SiC-SBD.Type: GrantFiled: November 17, 2017Date of Patent: May 11, 2021Assignee: SHINDENGEN ELECTRIC MANUFACTURING CO., LTD.Inventors: Daisuke Arai, Shigeru Hisada, Mizue Kitada
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Patent number: 10872952Abstract: A MOSFET according to the present invention includes a semiconductor base substrate having a super junction structure. A gate electrode is on a first main surface side of the semiconductor base substrate by way of a gate insulation film, wherein in a state where a total amount of dopant in an n-type column region differs from a total amount of dopant in a p-type column region, assuming a depth position where an average positive charge density ?(x) becomes 0 as Xm?, assuming a deepest depth position of the surface of the depletion layer on the first main surface side as X0?, assuming a depth position where the reference average positive charge density ?0(x) becomes 0 as Xm, and assuming a deepest depth position of the depletion layer on the first main surface side as X0, a relationship of |X0?X0?|<|Xm?Xm?| is satisfied.Type: GrantFiled: May 26, 2017Date of Patent: December 22, 2020Assignee: SHINDENGEN ELECTRIC MANUFACTURING CO., LTD.Inventors: Daisuke Arai, Mizue Kitada
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Publication number: 20200388671Abstract: A semiconductor device includes: a semiconductor base substrate including a semiconductor layer; a first main electrode; a second main electrode; a plurality of peripheral trenches formed on a surface of the semiconductor layer and having bottom portions covered by the semiconductor layer in a peripheral region; and a plurality of in-trench electrodes each embedded in each of the plurality of peripheral trenches byway of an insulation layer formed on an inner surface of the each peripheral trench, wherein the semiconductor base substrate further includes, in the peripheral region, a plurality of second conductive type floating regions disposed in the semiconductor layer at a depth position deeper than the bottom portions of the peripheral trenches in a spaced apart manner from the peripheral trenches and having a potential in a floating state.Type: ApplicationFiled: June 4, 2020Publication date: December 10, 2020Inventors: Gotaro TAKEMOTO, Toshihiro OKUDA, Mizue KITADA
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Publication number: 20200381510Abstract: A MOSFET according to the present invention includes a semiconductor base substrate having a super junction structure. A gate electrode is on a first main surface side of the semiconductor base substrate byway of a gate insulation film, wherein in a state where a total amount of dopant in an n-type column region differs from a total amount of dopant in a p-type column region, assuming a depth position where an average positive charge density ?(x) becomes 0 as Xm?, assuming a deepest depth position of the surface of the depletion layer on the first main surface side as X0?, assuming a depth position where the reference average positive charge density ?0(x) becomes 0 as Xm, and assuming a deepest depth position of the depletion layer on the first main surface side as X0, a relationship of |X0?X0?|<|Xm?Xm?| is satisfied.Type: ApplicationFiled: May 26, 2017Publication date: December 3, 2020Inventors: Daisuke ARAI, Mizue KITADA
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Patent number: 10818496Abstract: A MOSFET includes: a semiconductor base substrate having n-type column regions and p-type column regions, the n-type column regions and the p-type column regions forming a super junction structure; and a gate electrode which is formed on a first main surface side of the semiconductor base substrate by way of a gate insulation film, wherein crystal defects whose density is increased locally as viewed along a depth direction are formed in the n-type column regions and the p-type column regions, using the first main surface as a reference and assuming a depth to a deepest portion of the super junction structure as Dp, a depth at which density of the crystal defects exhibits a maximum value as Dd, and a half value width of density distribution of the crystal defects as W, a relationship of 0.25Dp?Dd<0.95Dp and a relationship of 0.05Dp<W<0.5Dp are satisfied.Type: GrantFiled: July 26, 2019Date of Patent: October 27, 2020Assignee: SHINDENGEN ELECTRIC MANUFACTURING CO., LTD.Inventors: Daisuke Arai, Mizue Kitada, Takeshi Asada, Noriaki Suzuki, Koichi Murakami
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Patent number: 10700191Abstract: A MOSFET used in a power conversion circuit including a reactor, a power source, the MOSFET, and a rectifier element, includes a semiconductor base substrate having an n-type column region and a p-type column region, the n-type column region and the p-type column region forming a super junction structure, the n-type column region and the p-type column region are formed such that a total amount of a dopant in the p-type column region is set higher than a total amount of a dopant in the n-type column region, and the MOSFET is configured to be operated in response to turning on of the MOSFET such that at a center of the n-type column region as viewed in a plan view, a low electric field region having lower field intensity than areas of the n-type column region other than the center of the n-type column region appears.Type: GrantFiled: September 16, 2016Date of Patent: June 30, 2020Assignee: SHINDENGEN ELECTRIC MANUFACTURING CO., LTD.Inventors: Daisuke Arai, Shigeru Hisada, Mizue Kitada, Takeshi Asada
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Publication number: 20200119187Abstract: A MOSFET includes: a semiconductor base substrate having an n-type column region and a p-type column region, the n-type column region and the p-type column region forming a super junction structure; and a gate electrode formed by way of a gate insulation film. Assuming a region of the semiconductor base substrate which provides a main operation of the MOSFET as an active region, a region of the semiconductor base substrate maintaining a withstand voltage of the MOSFET as an outer peripheral region, and a region of the semiconductor base substrate disposed between the active region and the outer peripheral region as an active connecting region, out of the active region, the active connecting region, and the outer peripheral region of the semiconductor base substrate, the crystal defects are formed only in the active region and the active connecting region.Type: ApplicationFiled: December 27, 2017Publication date: April 16, 2020Inventors: Daisuke ARAI, Mizue KITADA, Takeshi ASADA, Noriaki SUZUKI, Koichi MURAKAMI
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Publication number: 20200076290Abstract: A power conversion circuit includes: a MOSFET having a super junction structure; an inductive load; and a freewheel diode. A switching frequency of the MOSFET is 10 kHz or more. When the MOSFET is turned off, a first period during which a drain current decreases, a second period during which the drain current increases, and a third period during which the drain current decreases again appear in this order. The freewheel diode is an Si-FRD or an SiC-SBD, and current density obtained by dividing a current value of the forward current by an area of an active region of the freewheel diode falls within a range of 200 A/cm2 to 400 A/cm2 when the freewheel diode is the Si-FRD, and the current density falls within a range of 400 A/cm2 to 1500 A/cm2 when the freewheel diode is the SiC-SBD.Type: ApplicationFiled: November 17, 2017Publication date: March 5, 2020Inventors: Daisuke ARAI, Shigeru HISADA, Mizue KITADA
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Publication number: 20200020536Abstract: A MOSFET includes: a semiconductor base substrate having n-type column regions and p-type column regions, the n-type column regions and the p-type column regions forming a super junction structure; and a gate electrode which is formed on a first main surface side of the semiconductor base substrate by way of a gate insulation film, wherein crystal defects whose density is increased locally as viewed along a depth direction are formed in the n-type column regions and the p-type column regions, using the first main surface as a reference and assuming a depth to a deepest portion of the super junction structure as Dp, a depth at which density of the crystal defects exhibits a maximum value as Dd, and a half value width of density distribution of the crystal defects as W, a relationship of 0.25Dp?Dd<0.95Dp and a relationship of 0.05Dp<W<0.5Dp are satisfied.Type: ApplicationFiled: July 26, 2019Publication date: January 16, 2020Inventors: Daisuke ARAI, Mizue KITADA, Takeshi ASADA, Noriaki SUZUKI, Koichi Murakami
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Patent number: 10475917Abstract: A MOSFET includes a semiconductor base substrate where a super junction structure is formed of an n-type column region and a p-type column region. A total amount of a dopant in the n-type column region is set to a value greater than a total amount of a dopant in the p-type column region. The MOSFET is configured to be operated during a period from a point of time when a drain current starts to decrease to a point of time when the drain current becomes 0 for the first time in response to turning off of the MOSFET such that a first period during which the drain current is decreased, a second period during which the drain current is increased or the drain current becomes constant, and a third period during which the drain current is decreased again occur in this order.Type: GrantFiled: May 21, 2018Date of Patent: November 12, 2019Assignee: SHINDENGEN ELECTRIC MANUFACTURING CO., LTD.Inventors: Daisuke Arai, Shigeru Hisada, Mizue Kitada, Takeshi Asada
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Patent number: 10468480Abstract: Provided is a MOSFET which includes: a semiconductor base substrate having an n-type column region and a p-type column region, a base region and a source region, wherein a super junction structure is formed of the n-type column region and the p-type column region; a trench having side walls and a bottom; a gate electrode formed in the trench by way of a gate insulation film; a carrier compensation electrode positioned between the gate electrode and the bottom of the trench; an insulation region separating the carrier compensation electrode from the side walls and the bottom; and a source electrode electrically connected to the source region and also electrically connected to the carrier compensation electrode. According to the MOSFET of the present invention, even when an irregularity in a charge balance occurs around the gate, an irregularity in switching characteristics when the MOSFET is turned off can be decreased.Type: GrantFiled: November 11, 2016Date of Patent: November 5, 2019Assignee: SHINDENGEN ELECTRIC MANUFACTURING CO., LTD.Inventors: Daisuke Arai, Mizue Kitada
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Patent number: 10468518Abstract: A power semiconductor device of the present invention includes: a semiconductor base body which has a super junction structure formed of a plurality of first conductive-type columnar regions and a plurality of second conductive-type columnar regions; a plurality of trenches; gate insulation films; gate electrodes; an interlayer insulation film; contact holes formed such that two or more contact holes are formed between two trenches disposed adjacently to each other; metal plugs formed by filling the inside of the contact holes with metal; and an electrode, wherein a first conductive-type high concentration diffusion region is formed only between the trench and the metal plug disposed closest to the trench between each two trenches disposed adjacently to each other. According to the power semiconductor device of the present invention, it is possible to provide a power semiconductor device which satisfies a demand for reduction in cost and downsizing of electronic equipment, and has a large breakdown strength.Type: GrantFiled: January 16, 2017Date of Patent: November 5, 2019Assignee: SHINDENGEN ELECTRIC MANUFACTURING CO., LTD.Inventors: Mizue Kitada, Takeshi Asada, Takeshi Yamaguchi, Noriaki Suzuki, Daisuke Arai
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Publication number: 20190326388Abstract: Provided is a MOSFET which includes: a semiconductor base substrate having an n-type column region and a p-type column region, a base region and a source region, wherein a super junction structure is formed of the n-type column region and the p-type column region; a trench having side walls and a bottom; a gate electrode formed in the trench by way of a gate insulation film; a carrier compensation electrode positioned between the gate electrode and the bottom of the trench; an insulation region separating the carrier compensation electrode from the side walls and the bottom; and a source electrode electrically connected to the source region and also electrically connected to the carrier compensation electrode. According to the MOSFET of the present invention, even when an irregularity in a charge balance occurs around the gate, an irregularity in switching characteristics when the MOSFET is turned off can be decreased.Type: ApplicationFiled: November 11, 2016Publication date: October 24, 2019Inventors: Daisuke ARAI, Mizue KITADA
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Patent number: 10439056Abstract: A power semiconductor device according to the present invention has a super junction structure, and includes a low-resistance semiconductor layer, an n?-type column region, p?-type column regions, a base region, trenches, gate insulation films, gate electrodes, source regions, interlayer insulation films, contact holes, metal plugs, p+-type diffusion regions, a source electrode and a gate pad electrode. An active element part includes an n?-type column region between a predetermined p?-type column region disposed closest to a gate pad part and a predetermined n?-type column region disposed closest to the gate pad part among the n?-type column regions which are in contact with the trenches. The present invention provides a power semiconductor device which can satisfy a demand for reduction in cost and downsizing of electronic equipment, can lower ON resistance while maintaining a high withstand voltage, and can possess a large breakdown resistance.Type: GrantFiled: March 31, 2016Date of Patent: October 8, 2019Assignee: SHINDENGEN ELECTRIC MANUFACTURING CO., LTD.Inventors: Daisuke Arai, Mizue Kitada, Takeshi Asada, Takeshi Yamaguchi, Noriaki Suzuki
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Patent number: 10411141Abstract: A semiconductor device includes: a semiconductor base body where a second semiconductor layer is stacked on a first semiconductor layer, a trench is formed on a surface of the second semiconductor layer, and a third semiconductor layer which is formed of an epitaxial layer is formed in the inside of the trench; a first electrode; an interlayer insulation film which has a predetermined opening; and a second electrode, wherein metal is filled in the opening, the opening is disposed at a position avoiding a center portion of the third semiconductor layer, the second electrode is connected to the third semiconductor layer through the metal, and a surface of the center portion of the third semiconductor layer is covered by the interlayer insulation film.Type: GrantFiled: February 27, 2017Date of Patent: September 10, 2019Assignee: SHINDENGEN ELECTRIC MANUFACTURING CO., LTD.Inventors: Mizue Kitada, Takeshi Asada, Takeshi Yamaguchi, Noriaki Suzuki, Daisuke Arai
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Publication number: 20190221664Abstract: A MOSFET used in a power conversion circuit having a reactor, a power source, the MOSFET, and a rectifier element, includes a semiconductor base substrate with a super junction structure formed of an n-type column region and a p-type column region. A total amount of a dopant in the n-type column region is higher than a total amount of a dopant in the p-type column region. The MOSFET is configured to be operated during a period from a point of time when a drain current starts to decrease to a point of time when the drain current becomes 0 for the first time in response to turning off of the MOSFET such that a first period during which the drain current decreases, a second period during which the drain current increases, and a third period during which the drain current decreases again appear in this order.Type: ApplicationFiled: September 2, 2016Publication date: July 18, 2019Inventors: Daisuke ARAI, Shigeru HISADA, Mizue KITADA, Takeshi ASADA