Patents by Inventor Takahide Joichi
Takahide Joichi 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: 9362449Abstract: Disclosed herein are a high efficiency light emitting diode and a method of fabricating the same. The light emitting diode includes a semiconductor stacked structure disposed on the support substrate and including a gallium nitride-based p-type semiconductor layer, a gallium nitride-based active layer, and a gallium nitride-based n-type semiconductor layer; and a reflecting layer disposed between the support substrate and the semiconductor stacked structure, wherein the semiconductor stacked structure includes a plurality of protrusions having a truncated cone shape and fine cones formed on top surfaces of the protrusions. By this configuration, light extraction efficiency of the semiconductor stacked structure having low dislocation density can be improved.Type: GrantFiled: August 20, 2014Date of Patent: June 7, 2016Assignee: SEOUL VIOSYS CO., LTD.Inventors: Chang Yeon Kim, Dae Sung Cho, Ki Bum Nam, Young Wug Kim, Jong Kyun You, Kenji Shimoyama, Takahide Joichi, Kaori Kurihara
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Publication number: 20140353582Abstract: Disclosed herein are a high efficiency light emitting diode and a method of fabricating the same. The light emitting diode includes a semiconductor stacked structure disposed on the support substrate and including a gallium nitride-based p-type semiconductor layer, a gallium nitride-based active layer, and a gallium nitride-based n-type semiconductor layer; and a reflecting layer disposed between the support substrate and the semiconductor stacked structure, wherein the semiconductor stacked structure includes a plurality of protrusions having a truncated cone shape and fine cones formed on top surfaces of the protrusions. By this configuration, light extraction efficiency of the semiconductor stacked structure having low dislocation density can be improved.Type: ApplicationFiled: August 20, 2014Publication date: December 4, 2014Applicants: SEOUL VIOSYS CO., LTD., MITSUBISHI CHEMICAL CORPORATIONInventors: Chang Yeon KIM, Dae Sung CHO, Ki Bum NAM, Young Wug KIM, Jong Kyun YOU, Kenji SHIMOYAMA, Takahide JOICHI, Kaori KURIHARA
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Patent number: 8716728Abstract: A nitride semiconductor light-emitting diode element 1 includes a nitride semiconductor layer 12 having a bottom surface and an upper surface and containing a light emitting layer 12b inside, and a supporting substrate 11 made from a metal is bonded to the bottom surface of the nitride semiconductor layer 12. A light reflecting depression A1 to reflect light generated in the light emitting layer 12b is formed in the bottom surface of the nitride semiconductor layer 12. According to the nitride semiconductor light-emitting diode element 1, since the light generated from the light emitting layer 12b and propagated in the nitride semiconductor layer 12 in a layer direction is reflected by the light reflecting depression A1 and its travel direction is changed, the ratio of the light incident upon the upper surface of the nitride semiconductor layer 12 within a critical angle is increased.Type: GrantFiled: October 19, 2007Date of Patent: May 6, 2014Assignee: Mitsubishi Chemical CorporationInventors: Hiromitsu Kudo, Hirokazu Taniguchi, Hiroaki Okagawa, Shin Hiraoka, Takahide Joichi, Toshihiko Shima
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Patent number: 8455886Abstract: A light emitting device is constituted by flip-chip mounting a GaN-based LED chip. The GaN-based LED chip includes a light-transmissive substrate and a GaN-based semiconductor layer formed on the light-transmissive substrate, wherein the GaN-based semiconductor layer has a laminate structure containing an n-type layer, a light emitting layer and a p-type layer in this order from the light-transmissive substrate side, wherein a positive electrode is formed on the p-type layer, the electrode containing a light-transmissive electrode of an oxide semiconductor and a positive contact electrode electrically connected to the light-transmissive electrode, and the area of the positive contact electrode is half or less of the area of the upper surface of the p-type layer.Type: GrantFiled: March 13, 2012Date of Patent: June 4, 2013Assignee: Mitsubishi Chemical CorporationInventors: Takahide Joichi, Hiroaki Okagawa, Shin Hiraoka, Toshihiko Shima, Hirokazu Taniguchi
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Publication number: 20120175669Abstract: A light emitting device is constituted by flip-chip mounting a GaN-based LED chip. The GaN-based LED chip includes a light-transmissive substrate and a GaN-based semiconductor layer formed on the light-transmissive substrate, wherein the GaN-based semiconductor layer has a laminate structure containing an n-type layer, a light emitting layer and a p-type layer in this order from the light-transmissive substrate side, wherein a positive electrode is formed on the p-type layer, the electrode containing a light-transmissive electrode of an oxide semiconductor and a positive contact electrode electrically connected to the light-transmissive electrode, and the area of the positive contact electrode is half or less of the area of the upper surface of the p-type layer.Type: ApplicationFiled: March 13, 2012Publication date: July 12, 2012Inventors: Takahide Joichi, Hiroaki Okagawa, Shin Hiraoka, Toshihiko Shima, Hirokazu Taniguchi
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Publication number: 20120171796Abstract: A first conductive film 104-1 of a light-transmissive conductive oxide film 104 and a positive pad electrode 105 are electrically connected through a second conductive film 104-2 of the light-transmissive conductive oxide film 104 in a GaN-based LED element 100. A contact resistance of the light-transmissive conductive oxide film 104 with a p-type layer 102-3 in a first contact portion 104A is lower than in a second contact portion 104B, so that a current supplied from the positive pad electrode 105 to the p-type layer 102-3 through the conductive oxide film 104 flows to the p-type layer 102-3 mainly through the first contact portion 104A.Type: ApplicationFiled: March 13, 2012Publication date: July 5, 2012Inventors: Shin Hiraoka, Hiroaki Okagawa, Takahide Joichi
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Patent number: 8158990Abstract: A light emitting device is constituted by flip-chip mounting a GaN-based LED chip. The GaN-based LED chip includes a light-transmissive substrate and a GaN-based semiconductor layer formed on the light-transmissive substrate, wherein the GaN-based semiconductor layer has a laminate structure containing an n-type layer, a light emitting layer and a p-type layer in this order from the light-transmissive substrate side, wherein a positive electrode is formed on the p-type layer, the electrode containing a light-transmissive electrode of an oxide semiconductor and a positive contact electrode electrically connected to the light-transmissive electrode, and the area of the positive contact electrode is half or less of the area of the upper surface of the p-type layer.Type: GrantFiled: October 5, 2007Date of Patent: April 17, 2012Assignee: Mitsubishi Chemical CorporationInventors: Takahide Joichi, Hiroaki Okagawa, Shin Hiraoka, Toshihiko Shima, Hirokazu Taniguchi
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Patent number: 8158994Abstract: A first conductive film 104-1 of a light-transmissive conductive oxide film 104 and a positive pad electrode 105 are electrically connected through a second conductive film 104-2 of the light-transmissive conductive oxide film 104 in a GaN-based LED element 100. A contact resistance of the light-transmissive conductive oxide film 104 with a p-type layer 102-3 in a first contact portion 104A is lower than in a second contact portion 104B, so that a current supplied from the positive pad electrode 105 to the p-type layer 102-3 through the conductive oxide film 104 flows to the p-type layer 102-3 mainly through the first contact portion 104A.Type: GrantFiled: February 20, 2008Date of Patent: April 17, 2012Assignee: Mitsubishi Chemical CorporationInventors: Shin Hiraoka, Hiroaki Okagawa, Takahide Joichi
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Patent number: 8012783Abstract: The object of the present invention is to provide a semiconductor element containing an n-type gallium nitride based compound semiconductor and a novel electrode that makes an ohmic contact with the semiconductor. The semiconductor element of the present invention has an n-type Gallium nitride based compound semiconductor and an electrode that forms an ohmic contact with the semiconductor, wherein the electrode has a TiW alloy layer to be in contact with the semiconductor. According to a preferable embodiment, the above-mentioned electrode can also serve as a contact electrode. According to a preferable embodiment, the above-mentioned electrode is superior in the heat resistance. Moreover, a production method of the semiconductor element is also provided.Type: GrantFiled: April 4, 2006Date of Patent: September 6, 2011Assignee: Mitsubishi Chemical CorporationInventors: Tsuyoshi Takano, Takahide Joichi, Hiroaki Okagawa
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Publication number: 20100314642Abstract: A nitride semiconductor light-emitting diode element 1 includes a nitride semiconductor layer 12 having a bottom surface and an upper surface and containing a light emitting layer 12b inside, and a supporting substrate 11 made from a metal is bonded to the bottom surface of the nitride semiconductor layer 12. A light reflecting depression A1 to reflect light generated in the light emitting layer 12b is formed in the bottom surface of the nitride semiconductor layer 12. According to the nitride semiconductor light-emitting diode element 1, since the light generated from the light emitting layer 12b and propagated in the nitride semiconductor layer 12 in a layer direction is reflected by the light reflecting depression A1 and its travel direction is changed, the ratio of the light incident upon the upper surface of the nitride semiconductor layer 12 within a critical angle is increased.Type: ApplicationFiled: October 19, 2007Publication date: December 16, 2010Applicant: MITSUBISHI CHEMICAL CORPORATIONInventors: Hiromitsu Kudo, Hirokazu Taniguchi, Hiroaki Okagawa, Shin Hiraoka, Takahide Joichi, Toshihiko Shima
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Publication number: 20100019247Abstract: A light emitting device is constituted by flip-chip mounting a GaN-based LED chip 100 of the following (a): (a) the a GaN-based LED chip 100 comprising a light-transmissive substrate 101 and GaN-based semiconductor layer L formed on the light-transmissive substrate 101, wherein the GaN-based semiconductor layer L has a laminate structure containing n-type layer 102, light emitting layer 103 and p-type layer 104 in this order from the light-transmissive substrate 101 side, wherein a positive electrode E101 is formed on the p-type layer 104, said electrode E101 containing a light-transmissive electrode E101a of an oxide semiconductor and a positive contact electrode E101b electrically connected to the light-transmissive electrode, and the area of the positive contact electrode E101b is less than ½ of the area of the upper surface of the p-type layer 104.Type: ApplicationFiled: October 5, 2007Publication date: January 28, 2010Inventors: Takahide Joichi, Hiroaki Okagawa, Shin Hiraoka, Toshihiko Shima, Hirokazu Taniguchi
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Publication number: 20100012971Abstract: A first conductive film 104-1 and a positive pad electrode 105 are electrically connected through a second conductive film 104-2 in a GaN-based LED element 100. The contact resistance of a conductive oxide film 104 with a p-type layer 102-3 in a first contact portion 104A is made lower than in a second contact portion 104B, so that a current supplied from the positive pad electrode 105 to the p-type layer 102-3 through the conductive oxide film 104 flows to the p-type layer 102-3 mainly through the first contact portion 104A.Type: ApplicationFiled: February 20, 2008Publication date: January 21, 2010Inventors: Shin Hiraoka, Hiroaki Okagawa, Takahide Joichi
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Publication number: 20090065938Abstract: The object of the present invention is to provide a semiconductor element containing an n-type gallium nitride based compound semiconductor and a novel electrode that makes an ohmic contact with the semiconductor. The semiconductor element of the present invention has an n-type Gallium nitride based compound semiconductor and an electrode that forms an ohmic contact with the semiconductor, wherein the electrode has a TiW alloy layer to be in contact with the semiconductor. According to a preferable embodiment, the above-mentioned electrode can also serve as a contact electrode. According to a preferable embodiment, the above-mentioned electrode is superior in the heat resistance. Moreover, a production method of the semiconductor element is also provided.Type: ApplicationFiled: April 4, 2006Publication date: March 12, 2009Inventors: Tsuyoshi Takano, Takahide Joichi, Hiroaki Okagawa