Patents by Inventor Tatsuo Harada
Tatsuo Harada 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: 11824014Abstract: According to one aspect, a semiconductor device includes: a buffer layer disposed on a front surface of a second semiconductor layer, and having at least one opening in plan view; and an electrode disposed over the second semiconductor layer and the buffer layer, and being in contact with the second semiconductor layer through the at least one opening, wherein the buffer layer has a higher Vickers hardness than the electrode, and a width w of each of the at least one opening satisfies w<Wth, where s is a thickness of the buffer layer, t is a thickness of the electrode, and Wth=2×(s×t?s2)0.5 holds true.Type: GrantFiled: January 21, 2021Date of Patent: November 21, 2023Assignee: Mitsubishi Electric CorporationInventors: Akito Nishii, Tatsuo Harada, Katsumi Uryu, Noritsugu Nomura, Sho Tanaka
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Patent number: 11810970Abstract: A semiconductor device includes a substrate, a drift layer provided on an upper surface side of the substrate, a base layer provided on the upper surface side of the drift layer, an upper semiconductor layer provided on the upper surface side of the base layer, a first electrode provided on the upper surface of the substrate, a second electrode provided on a rear surface of the substrate, a trench extending to the drift layer from the upper surface of the substrate and a gate electrode provided inside the trench, wherein an inner side surface of the trench has a first surface and a second surface provided below the first surface, the second surface tilts inward of the trench with respect to the first surface, and an intersection point of the first surface and the second surface is provided below the base layer.Type: GrantFiled: August 10, 2021Date of Patent: November 7, 2023Assignee: Mitsubishi Electric CorporationInventor: Tatsuo Harada
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Publication number: 20230170404Abstract: Peak concentration of the carrier accumulation layer is equal to or higher than 1.0E16/cm3. A bottom part of the trench is positioned inside the n-type carrier accumulation layer. When a concentration ratio is a result of division of a concentration of the carrier accumulation layer by a concentration of the drift layer at a depth of the bottom part of the trench, the depth of the bottom part of the trench is a position at which the concentration ratio is larger than one and equal to or smaller than 10.Type: ApplicationFiled: July 6, 2022Publication date: June 1, 2023Applicant: Mitsubishi Electric CorporationInventor: Tatsuo HARADA
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Publication number: 20220254908Abstract: A semiconductor device includes a substrate, a drift layer provided on an upper surface side of the substrate, a base layer provided on the upper surface side of the drift layer, an upper semiconductor layer provided on the upper surface side of the base layer, a first electrode provided on the upper surface of the substrate, a second electrode provided on a rear surface of the substrate, a trench extending to the drift layer from the upper surface of the substrate and a gate electrode provided inside the trench, wherein an inner side surface of the trench has a first surface and a second surface provided below the first surface, the second surface tilts inward of the trench with respect to the first surface, and an intersection point of the first surface and the second surface is provided below the base layer.Type: ApplicationFiled: August 10, 2021Publication date: August 11, 2022Applicant: Mitsubishi Electric CorporationInventor: Tatsuo HARADA
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Publication number: 20220140748Abstract: An inverter device includes first and second input terminals, a series circuit having a plurality of switch elements coupled between the first and second input terminals. Each of the switch elements is coupled in parallel with a series circuit having a diode and an inductor.Type: ApplicationFiled: November 5, 2020Publication date: May 5, 2022Inventors: Tetsu TODA, Tatsuo HARADA, Daisuke IIJIMA, Syuuichi KIKUCHI, Kotaro KURODA
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Publication number: 20210305174Abstract: According to one aspect, a semiconductor device includes: a buffer layer disposed on a front surface of a second semiconductor layer, and having at least one opening in plan view; and an electrode disposed over the second semiconductor layer and the buffer layer, and being in contact with the second semiconductor layer through the at least one opening, wherein the buffer layer has a higher Vickers hardness than the electrode, and a width w of each of the at least one opening satisfies w<Wth, where s is a thickness of the buffer layer, t is a thickness of the electrode, and Wth=2×(s×t?s2)0.5 holds true.Type: ApplicationFiled: January 21, 2021Publication date: September 30, 2021Applicant: Mitsubishi Electric CorporationInventors: Akito NISHII, Tatsuo HARADA, Katsumi URYU, Noritsugu NOMURA, Sho TANAKA
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Patent number: 11004964Abstract: A semiconductor device includes: a second semiconductor layer in a surface layer of a first semiconductor layer; a third semiconductor layer in a surface layer of the second semiconductor layer; a first trench penetrating the second semiconductor layer and the third semiconductor layer to reach an inside of the first semiconductor layer; a second trench penetrating, from an upper surface of the first semiconductor layer, the third semiconductor layer to reach an inside of the second semiconductor layer; and a fourth semiconductor layer in contact with a bottom of the second trench.Type: GrantFiled: October 3, 2019Date of Patent: May 11, 2021Assignee: Mitsubishi Electric CorporationInventor: Tatsuo Harada
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Publication number: 20200194574Abstract: A semiconductor device includes: a second semiconductor layer in a surface layer of a first semiconductor layer; a third semiconductor layer in a surface layer of the second semiconductor layer; a first trench penetrating the second semiconductor layer and the third semiconductor layer to reach an inside of the first semiconductor layer; a second trench penetrating, from an upper surface of the first semiconductor layer, the third semiconductor layer to reach an inside of the second semiconductor layer, and a fourth semiconductor layer in contact with a bottom of the second trench.Type: ApplicationFiled: October 3, 2019Publication date: June 18, 2020Applicant: Mitsubishi Electric CorporationInventor: Tatsuo HARADA
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Patent number: 10411093Abstract: An active cell region, an edge termination region surrounding the active cell region and an intermediate region located at an intermediate position between these regions are provided, the active cell region has a trench gate type MOS structure on a top side, and a vertical structure on a bottom side includes a p-collector layer, an n-buffer layer on the p-collector layer, and an n-drift layer on the n-buffer layer, the n-buffer layer has a first buffer portion provided on the p-collector layer side, and a second buffer portion provided on the n-drift layer side, the peak impurity concentration of the first buffer portion is higher than the peak impurity concentration of the second buffer portion, and the impurity concentration gradient on the n-drift layer side of the second buffer portion is gentler than the impurity concentration gradient on the n-drift layer side of the first buffer portion.Type: GrantFiled: December 28, 2015Date of Patent: September 10, 2019Assignee: Mitsubishi Electric CorporationInventors: Katsumi Nakamura, Tatsuo Harada, Noritsugu Nomura
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Publication number: 20190109026Abstract: Provided is a technique for detaching a semiconductor chip from a mount tape without failures in the semiconductor chip, such as cracking and chipping. A semiconductor pick-up apparatus includes the following components: a pick-up stage above which a semiconductor chip is to be placed through a mount tape attached to the lower surface of the semiconductor chip; an expander holding and expanding the mount tape; a push-up needle projecting from the upper surface of the pick-up stage, and capable of pushing up the semiconductor chip through the mount tape; and a mechanism pushing up the push-up needle while operating the push-up needle so as to form a spiral shape.Type: ApplicationFiled: August 6, 2018Publication date: April 11, 2019Applicant: Mitsubishi Electric CorporationInventors: Kinya YAMASHITA, Masaki UENO, Tatsuo HARADA, Noritsugu NOMURA
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Publication number: 20180248003Abstract: An active cell region, an edge termination region surrounding the active cell region and an intermediate region located at an intermediate position between these regions are provided, the active cell region has a trench gate type MOS structure on a top side, and a vertical structure on a bottom side includes a p-collector layer, an n-buffer layer on the p-collector layer, and an n-drift layer on the n-buffer layer, the n-buffer layer has a first buffer portion provided on the p-collector layer side, and a second buffer portion provided on the n-drift layer side, the peak impurity concentration of the first buffer portion is higher than the peak impurity concentration of the second buffer portion, and the impurity concentration gradient on the n-drift layer side of the second buffer portion is gentler than the impurity concentration gradient on the n-drift layer side of the first buffer portion.Type: ApplicationFiled: December 28, 2015Publication date: August 30, 2018Applicant: Mitsubishi Electric CorporationInventors: Katsumi NAKAMURA, Tatsuo HARADA, Noritsugu NOMURA
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Publication number: 20170154955Abstract: A semiconductor device includes: a semiconductor substrate; a device region on the semiconductor substrate; a planar edge termination region on the semiconductor substrate to surround the device region; and a passivation film covering the edge termination region, wherein the passivation film includes a semi-insulating film directly contacting the semiconductor substrate.Type: ApplicationFiled: June 6, 2016Publication date: June 1, 2017Applicant: Mitsubishi Electric CorporationInventors: Tatsuo HARADA, Shigeto HONDA, Akito NISHII, Ze CHEN
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Publication number: 20140199823Abstract: An SOT substrate (6), in which a silicon layer (5) is provided on a silicon substrate (3) via a silicon oxide film (4), is formed. Next, a plurality of semiconductor elements (8) is formed on a surface of the silicon layer (5). Next, wiring (11) is formed on a surface of an insulating substrate (10). Next, the SOI substrate (6) and the insulating substrate (10) are pasted together so that the plurality of semiconductor elements (8) and the wiring (11) are electrically connected together. Next, at least one of hydrogen ions and rare gas ions are injected into the silicon substrate (3) to form a brittle layer (12). Next, part of the silicon substrate (3) is peeled away from the brittle layer (12) as a boundary.Type: ApplicationFiled: June 10, 2011Publication date: July 17, 2014Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Noritsugu Nomura, Akira Okada, Tatsuo Harada
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Patent number: 8112980Abstract: A finish for synthetic filament yarn which decreases broken filaments and ends down in friction false-twist texturing includes 40 to 98 wt % of a polyether compound, and essentially comprises components (A) and (B); wherein the component (A) is at least one member selected from the group consisting of (A1) a C1-C10 fatty acid, (A2) a C1-C10 hydroxyfatty acid, (A3) a sarcosine derivative, and salts thereof, and the amount of the component (A) in the finish ranges from 0.05 to 5 wt %; and wherein the component (B) is an alkylphosphate salt and the amount of the component (B) in the finish ranges from 0.01 to 3 wt %.Type: GrantFiled: September 2, 2008Date of Patent: February 14, 2012Assignee: Matsumoto Yushi-Seiyaku Co., Ltd.Inventors: Shinichi Tatemoto, Tatsuo Harada, Kaori Kimoto
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Publication number: 20100199624Abstract: The present invention aims to provide a finish for synthetic filament yarn processed in friction false-twist texturing, which decreases broken filaments and ends down in false-twist texturing with a synthetic filament yarn applied with the finish, finish-application emulsion of the finish, synthetic filament yarn applied with the emulsion, manufacturing process of the synthetic filament yarn, and resultant yarns. The finish for synthetic filament yarn processed in friction false-twist texturing of the present invention comprises 40 to 98 wt % of a polyether compound, and essentially comprises components (A) and (B); wherein the component (A) is at least one member selected from the group consisting of (A1) a C1-C10 fatty acid, (A2) a C1-C10 hydroxyfatty acid, (A3) a sarcosine derivative, and salts thereof, and the amount of the component (A) in the finish ranges from 0.05 to 5 wt %; and wherein the component (B) is an alkylphosphate salt and the amount of the component (B) in the finish ranges from 0.Type: ApplicationFiled: September 2, 2008Publication date: August 12, 2010Applicant: MATSUMOTO YUSHI-SEIYAKU CO., LTD.Inventors: Shinichi Tatemoto, Tatsuo Harada, Kaori Kimoto
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Patent number: 7750438Abstract: An n-type buffer region 6 is arranged between an n? drift region 1 and a p-type collector region 7, and has a higher impurity concentration than n? drift region 1 Assuming that ? represents the ratio (WTA/WTB) between WTA expressed as: WTA = 2 ? ? s ? ? 0 ? V qNd and the thickness WTB of the drift region held between the base region and the buffer region, the ratio (DC/DB) of the net dose DC of the collector region with respect to the net dose DB of the buffer region is at least ?. Thus, a semiconductor device capable of ensuring a proper margin of SCSOA resistance can be obtained.Type: GrantFiled: January 21, 2009Date of Patent: July 6, 2010Assignee: Mitsubishi Electric CorporationInventor: Tatsuo Harada
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Publication number: 20100052011Abstract: An n-type buffer region 6 is arranged between an n? drift region 1 and a p-type collector region 7, and has a higher impurity concentration than n? drift region 1 Assuming that ? represents the ratio (WTA/WTB) between WTA expressed as: WTA = 2 ? ? s ? ? 0 ? V qNd and the thickness WTB of the drift region held between the base region and the buffer region, the ratio (DC/DB) of the net dose DC of the collector region with respect to the net dose DB of the buffer region is at least ?. Thus, a semiconductor device capable of ensuring a proper margin of SCSOA resistance can be obtained.Type: ApplicationFiled: January 21, 2009Publication date: March 4, 2010Applicant: MITSUBISHI ELECTRIC CORPORATIONInventor: Tatsuo HARADA
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Patent number: 7615846Abstract: An emitter layer is provided in stripes in a direction orthogonal to an effective gate trench region connected to a gate electrode and a dummy trench region isolated from the gate electrode. A width of the emitter layer is determined to satisfy a predetermined relational expression so as not to cause latch-up in an underlying P base layer. In the predetermined relational expression, an upper limit value of the width W of the emitter layer is (3500/Rspb)·Wso·exp(decimation ratio), where Rspb is a sheet resistance of the P base layer immediately below the emitter layer, Wso is an interval between the trenches, and the decimation ratio is a ratio of the number of the effective gate trench region to the total number of the trench regions. Variations in saturation current in a trench IGBT can be suppressed, and a tolerance of an Reverse Bias Safe Operation Area can be improved.Type: GrantFiled: December 31, 2007Date of Patent: November 10, 2009Assignee: Mitsubishi Electric CorporationInventor: Tatsuo Harada
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Publication number: 20090020852Abstract: An emitter layer is provided in stripes in a direction orthogonal to an effective gate trench region connected to a gate electrode and a dummy trench region isolated from the gate electrode. A width of the emitter layer is determined to satisfy a predetermined relational expression so as not to cause latch-up in an underlying P base layer. In the predetermined relational expression, an upper limit value of the width W of the emitter layer is (3500/Rspb)·Wso·exp(decimation ratio), where Rspb is a sheet resistance of the P base layer immediately below the emitter layer, Wso is an interval between the trenches, and the decimation ratio is a ratio of the number of the effective gate trench region to the total number of the trench regions. Variations in saturation current in a trench IGBT can be suppressed, and a tolerance of an Reverse Bias Safe Operation Area can be improved.Type: ApplicationFiled: December 31, 2007Publication date: January 22, 2009Applicant: MITSUBISHI ELECTRIC CORPORATIONInventor: Tatsuo HARADA
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Patent number: 7358565Abstract: An n-type first base layer is formed on a semiconductor substrate 1 having a first major surface and a second major surface, and a p-type second base layer is formed thereon. Between the first base layer and the second base layer, a carrier stored layer is formed. The carrier stored layer has a high-concentration impurity layer and a low concentration impurity layer, and the high-concentration impurity layer has a thickness of 1.5 ?m or more and an impurity concentration therethrough is made to be 1.0×1016 cm?3 or more throughout the layer.Type: GrantFiled: September 5, 2006Date of Patent: April 15, 2008Assignee: Mitsubishi Electric CorporationInventor: Tatsuo Harada