Light emitting apparatus

• US 20080210959A1
• Filed: 03/27/2007
• Published: 09/04/2008
• Est. Priority Date: 08/26/2003
• Status: Active Grant

• Current Assignee: Sumitomo Electric Industries Limited (Sumitomo Corporation)
• Original Assignee: Sumitomo Electric Industries Limited (Sumitomo Corporation)
• Inventors: Akita, Katsushi, Sakurada, Takashi, Katayama, Koji, Nakamura, Takao, Kiyama, Makoto, Nagai, Youichi, Uematsu, Koji, Yoshimoto, Susumu, Ikeda, Ayako
• Granted Patent: US 7,687,822 B2
• Time in Patent Office: Days
• US Class Current: 257/94
• CPC Class Codes: H01L 2224/05573 Single external layer
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/06102 the bonding areas being at different heights
• CPC Class Codes: H01L 2224/16245 the item being metallic
• CPC Class Codes: H01L 2224/1703 Bump connectors having different sizes, e.g. different diameters, heights or widths
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/45139 Silver (Ag) as principal constituent
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00011 Not relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01049 Indium [In]
• CPC Class Codes: H01L 2924/20752 : larger or equal to 20 microns less than 30 microns
• CPC Class Codes: H01L 2924/2076 : equal to or larger than 100 microns
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding
• CPC Class Codes: H01L 33/20 : with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/32 : containing nitrogen
• CPC Class Codes: H01L 33/382 : the electrode extending partially in or entirely through the semiconductor body
• CPC Class Codes: H01L 33/505 : characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/507 : the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H01L 33/58 : Optical field-shaping elements

Abstract

In order to provide light emitting devices which have simple constructions and thus can be fabricated easily, and can stably provide high light emission efficiencies for a long time period, a light emitting device includes an n-type nitride semiconductor layer at a first main surface side of a nitride semiconductor substrate, a p-type nitride semiconductor layer placed more distantly from the nitride semiconductor substrate than the n-type nitride semiconductor layer at the first main surface side and a light emitting layer placed between the n-type nitride semiconductor layer and the p-type nitride semiconductor layer at the first main surface side. The nitride semiconductor substrate has a resistivity of 0.5 Ω·cm or less and the p-type nitride semiconductor layer side is down-mounted so that light is emitted from the second main surface of the nitride semiconductor substrate at the opposite side from the first main surface.

Claims

1-39. -39. (canceled)

40. A light emitting apparatus comprising:

a GaN substrate which is a nitride semiconductor substrate;

an n-type Al_xGa_1-xN layer (x is in the range of from 0 to

     1) which is an n-type nitride semiconductor layer at a first main surface side of said GaN substrate;

a p-type Al_xGa_1-xN layer (x is within the range of from 0 to

     1), at said first main surface side, placed more distantly from said GaN substrate than said n-type Al_xGa_1-xN layer; and

a light emitting layer at said first main surface side, placed between said n-type Al_xGa_1-xN layer and said p-type Al_xGa_1-xN layer, wherein

said GaN substrate has a dislocation density of 10⁸/cm² or less, and said p-type Al_xGa_1-xN layer side is down-mounted so that light is emitted from the second main surface of said GaN substrate at the opposite side from the first main surface, wherein

between said GaN substrate and said n-type Al_xGa_1-xN layer (x is within the range of from 0 to

     1), an n-type AlGaN buffer layer is placed in contact with said GaN substrate and an n-type GaN buffer layer is placed in contact with the n-type AlGaN buffer layer, and said n-type Al_xGa_1-xN layer (x is within the range of from 0 to

     1) is placed in contact with the n-type GaN buffer layer.

41. The light emitting apparatus according to claim 40, wherein

said GaN substrate includes areas with an off-angle of 0.10°

or less and areas with an off-angle of 1.0°

or greater.

42. The light emitting apparatus according to claim 40, wherein

dislocation bundles are distributed in said GaN substrate and said dislocation bundles are not transferred to said n-type Al_xGa_1-xN layer (x is within the range of 0 to 1) placed in contact with said GaN buffer layer.

43. A light emitting apparatus comprising:

a GaN substrate which is a nitride semiconductor substrate;

an n-type Al_xGa_1-xN layer (x is in the range of from 0 to

     1) which is an n-type nitride semiconductor layer at a first main surface side of said GaN substrate;

a p-type Al_xGa_1-xN layer (x is within the range of from 0 to

     1), at said first main surface side, placed more distantly from said GaN substrate than said n-type Al_xGa_1-xN layer; and

a light emitting layer, at said first main surface side, placed between said n-type Al_xGa_1-xN layer and said p-type Al_xGa_1-xN layer,

further comprising a p-type GaN buffer layer placed at the down side in contact with said p-type Al_xGa_1-xN layer (x is within the range of from 0 to

     1) and a p-type InGaN contact layer placed in contact with the p-type GaN buffer layer.

44. The light emitting apparatus according to claim 43, wherein

the Mg concentration of said p-type InGaN contact layer is within the range of Mg atoms 1E18/cm³ to 1E21/cm³.

45. The light emitting apparatus according to claim 43 comprising a p-electrode layer formed from any one of Ag, Al and Rh in contact with said p-type InGaN contact layer.

46. A light emitting apparatus comprising:

a GaN substrate which is a nitride semiconductor substrate;

an n-type Al_xGa_1-xN layer (x is in the range of from 0 to

     1) which is an n-type nitride semiconductor layer at a first main surface side of said GaN substrate;

a p-type Al_xGa_1-xN layer (x is within the range of from 0 to

     1) at said first main surface side placed more distantly from said GaN substrate than said n-type Al_xGa_1-xN layer; and

a light emitting layer, at said first main surface side, placed between said n-type Al_xGa_1-xN layer and said p-type Al_xGa_1-xN layer, wherein

said GaN substrate includes plate-shape crystal inversion domains extending continuously in a plane shape in the thick-wise direction and a single direction within the GaN substrate surface, the plate-shape crystal inversion domains within the GaN substrate surface and plate-shape crystal inversion domains propagated to said n-type and p-type nitride semiconductor layers formed on said GaN substrate are removed from said p-type nitride semiconductor layers side through said n-type nitride semiconductor layers to a position inside of said GaN substrate, and in contact with the left p-type nitride semiconductor layers, p-electrodes are provided on the respective p-type nitride semiconductor layers.

47. The light emitting apparatus according to claim 46, wherein

said plate-shape crystal inversion domains are removed to a position inside of said GaN substrate by KOH solution.

48. (canceled)