High efficiency light-emitting diode and method for manufacturing the same

Abstract

A high efficiency light-emitting diode and a method for manufacturing the same are described. The high efficiency light-emitting diode comprises: a permanent substrate; a first contact metal layer and a second contact metal layer respectively deposed on two opposite surfaces of the permanent substrate; a bonding layer deposed on the second contact metal layer; a diffusion barrier layer deposed on the bonding layer, wherein the permanent substrate, the bonding layer and the diffusion barrier layer are electrically conductive; a reflective metal layer deposed on the diffusion barrier layer; a transparent conductive oxide layer deposed on the reflective metal layer; an illuminant epitaxial structure deposed on the transparent conductive oxide layer, wherein the illuminant epitaxial structure includes a first surface and a second surface opposite to the first surface; and a second conductivity type compound electrode pad deposed on the second surface of the illuminant epitaxial structure.

What is claimed is: 
     
         1 . A high efficiency light-emitting diode, comprising:
 an illuminant epitaxial structure including a first surface and a second surface on opposite sides;   a patterned ohmic contact layer on the illuminant epitaxial structure and exposing a portion of the illuminant epitaxial structure; and   a patterned ohmic contact metal layer directly on the patterned ohmic contact semiconductor layer and exposing a portion of the illuminant epitaxial structure.   
     
     
         2 . The high efficiency light-emitting diode according to  claim 1 , wherein the illuminant epitaxial structure comprises a first conductivity type cladding layer, an active layer, a second conductivity type cladding layer stacked in sequence, and the first conductivity type cladding layer and the second conductivity type cladding layer are different conductivity types. 
     
     
         3 . The high efficiency light-emitting diode according to  claim 2 , wherein the first conductivity type cladding layer is N-type, and the second conductivity type cladding layer is P-type. 
     
     
         4 . The high efficiency light-emitting diode according to  claim 3 , wherein the first conductivity type cladding layer or the second conductivity type cladding layer comprises a material selected from the group consisting of Al x Ga 1-x As and (Al x Ga 1-x ) y In 1-y P. 
     
     
         5 . The high efficiency light-emitting diode according to  claim 3 , wherein the illuminant epitaxial structure further comprises a transparent current-spreading layer on the second conductivity type cladding layer, and the transparent current-spreading layer comprises a material from the group consisting of GaP, GaAsP, AlGaAs and AlGaInP. 
     
     
         6 . The high efficiency light-emitting diode according to  claim 1 , further comprising a second conductivity type compound electrode pad comprising a contact metal layer and a bonding metal pad stacked on the second surface of the illuminant epitaxial structure. 
     
     
         7 . The high efficiency light-emitting diode according to  claim 6 , wherein the contact metal layer comprises a material selected from the group consisting of AuBe, AuZn and CrAu, and the bonding metal pad comprises a material selected from the group consisting of Au and Al. 
     
     
         8 . The high efficiency light-emitting diode according to  claim 1 , further comprising a transparent conductive oxide layer covering the patterned ohmic contact metal layer and contacting a portion of the first surface of the illuminant epitaxial structure. 
     
     
         9 . The high efficiency light-emitting diode according to  claim 1 , further comprising a substrate; and a bonding layer bonding the illuminant epitaxial structure and the substrate. 
     
     
         10 . The high efficiency light-emitting diode according to  claim 9 , wherein the bonding layer comprises a material selected from the group consisting of PbSn, AuGe, AuBe, AuSn, Sn, In, PdIn and Si. 
     
     
         11 . The high efficiency light-emitting diode according to  claim 10 , further comprising a reflective metal layer between the patterned ohmic contact metal layer and the substrate. 
     
     
         12 . The high efficiency light-emitting diode according to  claim 11 , wherein the reflective metal layer comprises a material, selected from the group consisting of Au, Al, Ag, Cr and Ni. 
     
     
         13 . The high efficiency light-emitting diode according to  claim 8 , wherein the transparent conductive oxide layer comprises a material selected from the group consisting of In 2 O 3 , SnO 2 , ZnO, ITO, CTO, CuAlO 2 , CuGaO 2  and SrCu 2 O 2 . 
     
     
         14 . The high efficiency light-emitting diode according to  claim 1 , wherein the ohmic contact layer comprises a material selected from the group consisting of GaAs, GaAsP and AlGaInP. 
     
     
         15 . The high efficiency light-emitting diode according to  claim 1 , wherein the ohmic contact metal layer comprises a material selected from the group consisting of AuGe/Au, Au/AuGe/Au and AuGe/Ni/Au. 
     
     
         16 . The high efficiency light-emitting diode according to  claim 11 , further comprising a diffusion barrier layer between the bonding layer and the reflective metal layer. 
     
     
         17 . The high efficiency light-emitting diode according to  claim 16 , wherein the diffusion barrier layer comprises Mo, Pt, W, ITO, ZnO or MnO. 
     
     
         18 . The high efficiency light-emitting diode according to  claim 9 , further comprising a first contact metal layer and a second contact metal layer on opposite sides of the substrate. 
     
     
         19 . The high efficiency light-emitting diode according to  claim 1 , further comprising a second conductivity type compound electrode pad on a portion of the second surface of the illuminant epitaxial structure. 
     
     
         20 . The high efficiency light-emitting diode according to  claim 9 , wherein the substrate and the bonding layer are electrically conductive. 
     
     
         21 . The high efficiency light-emitting diode according to  claim 9 , wherein the substrate comprises a material selected from the group consisting of Si, Ge, SiC, AlN, Cu and Al.