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).

  • Patent number: 9362449
    Abstract: 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: Grant
    Filed: August 20, 2014
    Date of Patent: June 7, 2016
    Assignee: 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
  • Publication number: 20140353582
    Abstract: 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: Application
    Filed: August 20, 2014
    Publication date: December 4, 2014
    Applicants: SEOUL VIOSYS CO., LTD., MITSUBISHI CHEMICAL CORPORATION
    Inventors: Chang Yeon KIM, Dae Sung CHO, Ki Bum NAM, Young Wug KIM, Jong Kyun YOU, Kenji SHIMOYAMA, Takahide JOICHI, Kaori KURIHARA
  • Patent number: 8716728
    Abstract: 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: Grant
    Filed: October 19, 2007
    Date of Patent: May 6, 2014
    Assignee: Mitsubishi Chemical Corporation
    Inventors: Hiromitsu Kudo, Hirokazu Taniguchi, Hiroaki Okagawa, Shin Hiraoka, Takahide Joichi, Toshihiko Shima
  • Patent number: 8455886
    Abstract: 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: Grant
    Filed: March 13, 2012
    Date of Patent: June 4, 2013
    Assignee: Mitsubishi Chemical Corporation
    Inventors: Takahide Joichi, Hiroaki Okagawa, Shin Hiraoka, Toshihiko Shima, Hirokazu Taniguchi
  • Publication number: 20120175669
    Abstract: 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: Application
    Filed: March 13, 2012
    Publication date: July 12, 2012
    Inventors: Takahide Joichi, Hiroaki Okagawa, Shin Hiraoka, Toshihiko Shima, Hirokazu Taniguchi
  • Publication number: 20120171796
    Abstract: 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: Application
    Filed: March 13, 2012
    Publication date: July 5, 2012
    Inventors: Shin Hiraoka, Hiroaki Okagawa, Takahide Joichi
  • Patent number: 8158994
    Abstract: 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: Grant
    Filed: February 20, 2008
    Date of Patent: April 17, 2012
    Assignee: Mitsubishi Chemical Corporation
    Inventors: Shin Hiraoka, Hiroaki Okagawa, Takahide Joichi
  • Patent number: 8158990
    Abstract: 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: Grant
    Filed: October 5, 2007
    Date of Patent: April 17, 2012
    Assignee: Mitsubishi Chemical Corporation
    Inventors: Takahide Joichi, Hiroaki Okagawa, Shin Hiraoka, Toshihiko Shima, Hirokazu Taniguchi
  • Patent number: 8012783
    Abstract: 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: Grant
    Filed: April 4, 2006
    Date of Patent: September 6, 2011
    Assignee: Mitsubishi Chemical Corporation
    Inventors: Tsuyoshi Takano, Takahide Joichi, Hiroaki Okagawa
  • Publication number: 20100314642
    Abstract: 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: Application
    Filed: October 19, 2007
    Publication date: December 16, 2010
    Applicant: MITSUBISHI CHEMICAL CORPORATION
    Inventors: Hiromitsu Kudo, Hirokazu Taniguchi, Hiroaki Okagawa, Shin Hiraoka, Takahide Joichi, Toshihiko Shima
  • Publication number: 20100019247
    Abstract: 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: Application
    Filed: October 5, 2007
    Publication date: January 28, 2010
    Inventors: Takahide Joichi, Hiroaki Okagawa, Shin Hiraoka, Toshihiko Shima, Hirokazu Taniguchi
  • Publication number: 20100012971
    Abstract: 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: Application
    Filed: February 20, 2008
    Publication date: January 21, 2010
    Inventors: Shin Hiraoka, Hiroaki Okagawa, Takahide Joichi
  • Publication number: 20090065938
    Abstract: 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: Application
    Filed: April 4, 2006
    Publication date: March 12, 2009
    Inventors: Tsuyoshi Takano, Takahide Joichi, Hiroaki Okagawa