Semiconductor light-emitting device and method for producing semiconductor light-emitting device

{
  "publication_number": "US2010219436A1",
  "country": "US",
  "kind": "A1",
  "title": "Semiconductor light-emitting device and method for producing semiconductor light-emitting device",
  "abstract": "The present invention provides a semiconductor light-emitting device that includes a compound semiconductor layer formed by laminating a first clad layer, a light-emitting layer and a second clad layer, a plurality of first ohmic electrodes formed on the first clad layer, a plurality of second ohmic electrodes formed on the second clad layer, a transparent conductive film that is formed on the first clad layer of the compound semiconductor layer and is conductively connected to the first ohmic electrodes, a bonding electrode formed on the transparent conducting film, and a support plate that is positioned on the second clad layer side of the compound semiconductor layer and is conductively connected to the second ohmic electrodes.",
  "claims": [
    "1. A semiconductor light-emitting device, comprising: a compound semiconductor layer formed by laminating at least a first conductive type first clad layer formed from a group III-V compound semiconductor, a light-emitting layer formed from either a first conductive type or an opposite second conductive type group III-V compound semiconductor, and a second conductive type second clad layer formed from a group III-V compound semiconductor, a plurality of first ohmic electrodes formed on said first clad layer, a plurality of second ohmic electrodes formed on said second clad layer, a transparent conductive film that is formed on said first clad layer of said compound semiconductor layer and is conductively connected to said first ohmic electrodes, a bonding electrode formed on said transparent conductive film, and a support plate that is positioned on a side of said second clad layer of said compound semiconductor layer and is conductively connected to said second ohmic electrodes, in which said first ohmic electrodes are positioned by being dispersed across a surface of said first clad layer, a plurality of depressions are provided within a bonding surface of said second clad layer on a side of said support plate, and said second ohmic electrodes are positioned within bottom portions of said depressions, said compound semiconductor layer is provided with a current diffusion layer that coats said bonding surface of said second clad layer, surfaces of said second ohmic electrodes within said depressions, and side portions of said depressions, and said support plate is bonded to said current diffusion layer.",
    "2. The semiconductor light-emitting device according to claim 1, wherein a surface of said current diffusion layer that contacts said second clad layer is composed of a metal material that does not form a eutectic composition with said group III-V compound semiconductor material of said second clad layer.",
    "3. The semiconductor light-emitting device according to claim 1, wherein voids derived from said depressions and surrounded by said current diffusion layer and said support plate are hollow spaces.",
    "4. The semiconductor light-emitting device according to claim 3, wherein said voids are provided in positions projected vertically down from said first ohmic electrodes.",
    "5. A method for producing a semiconductor light-emitting device, said method comprising: a compound semiconductor layer formation step of sequentially forming at least a first conductive type first clad layer formed from a group III-V compound semiconductor, a light-emitting layer formed from either a first conductive type or an opposite second conductive type group III-V compound semiconductor, and a second conductive type second clad layer formed from a group III-V compound semiconductor on top of a substrate, a depression formation step of forming a plurality of depressions in an upper surface of said second clad layer, a second ohmic electrode formation step of forming second ohmic electrodes within bottom portions of said depressions, a current diffusion layer formation step of forming a current diffusion layer that coats surfaces of said second ohmic electrodes within said depressions, side portions of said depressions, and a surface of said second clad layer in a region outside of said depressions, a support plate bonding step of bonding said current diffusion layer to a support plate having a bonding surface for bonding to said current diffusion layer that is coated with an identical material to a material of said current diffusion layer, so that voids are left within said depressions, a substrate removal step of removing said substrate, a first ohmic electrode formation step of forming first ohmic electrodes in a dispersed arrangement across an upper surface of said first clad layer, and a bonding electrode formation step of coating a region surrounding said first ohmic electrodes with a transparent conductive film, and forming a bonding electrode on an upper surface of said transparent conductive film.",
    "6. The method for producing a compound semiconductor device according to claim 5, wherein said current diffusion layer formation step comprises performing coating with said current diffusion layer that is composed of a metal material that does not form a eutectic composition with a group III-V compound semiconductor layer of said second clad layer.",
    "7. The method for producing a compound semiconductor device according to claim 5, wherein said current diffusion layer formation step comprises performing coating with said current diffusion layer such that hollow spaces are left within said depressions.",
    "8. The method for producing a compound semiconductor device according to claim 7, wherein said first ohmic electrode formation step comprises forming said first ohmic electrodes on an upper surface of said first clad layer, in positions projected vertically upward from said voids.",
    "9. The semiconductor light-emitting device according to claim 2, wherein voids derived from said depressions and surrounded by said current diffusion layer and said support plate are hollow spaces.",
    "10. The method for producing a compound semiconductor device according to claim 6, wherein said current diffusion layer formation step comprises performing coating with said current diffusion layer such that hollow spaces are left within said depressions."
  ],
  "description_excerpt": "The present invention relates to a semiconductor light-emitting device and a method for producing the light-emitting device.\n\nPriority is claimed on Japanese Patent Application No. 2007-257234, filed Oct. 1, 2007, the content of which is incorporated herein by reference.\n\nConventional examples of known light-emitting diodes (abbreviation: LED) capable of emitting red, orange, yellow or yellow-green visible light include compound semiconductor LEDs provided with a light-emitting layer composed of aluminum gallium indium phosphide (composition formula (Al X Ga 1-X) Y In 1-Y P, wherein 0≦X≦1 and 0<Y≦1). In this type of LED, the light-emitting portion provided with the light-emitting layer composed of (Al X Ga 1-X) y In 1-Y P (wherein 0≦X≦1 and 0<Y≦1) is generally formed on top of a substrate material such as gallium arsenide (GaAs), which is optically opaque relative to the light emitted from the light-emitting layer, and does not have a particularly high mechanical strength.\n\nRecently, in order to obtain visible LEDs of higher brightness and further improve the mechanical strength of the devices, techniques have been disclosed in which the substrate material that is opaque relative to the emitted light is removed from the compound semiconductor layer that includes the light-emitting layer, and then a support layer formed from a transparent material (namely, a transparent substrate) transmitting the emitted light and also having superior mechanical strength to conventional ...",
  "cpc": [
    "H10H 20/8312",
    "H10H 20/018"
  ],
  "ipc": [
    "H01L 33/48",
    "H01L 33/06",
    "H01L 33/14",
    "H01L 33/30",
    "H01L 33/38",
    "H10P 95/00",
    "H01L 33/00"
  ],
  "assignees": [
    "Showa Denko KK"
  ],
  "inventors": [
    "Takashi Watanabe"
  ],
  "filing_date": "2008-09-29",
  "publication_date": "2010-09-02",
  "priority_date": "2007-10-01",
  "application_number": "US-68073808-A",
  "family_id": "40526127",
  "cited_by_count": 30,
  "citations": [
    "US6711192B1",
    "US20060284195A1",
    "US20080267238A1"
  ]
}