High brightness led and method for producing the same

Abstract

The present invention discloses a high brightness LED (light emitting diode) and a method for producing the same. The LED of the present invention primarily includes a permanent substrate, LED epitaxial layers with a p-n or n-p junction structure, a layered structure formed between the permanent substrate and the LED epitaxial layers, a first electrode and a second electrode. The layered structure may include single layer, two layers or three layers. For the three layers structure, a reflective layer, a diffusion barrier and a buffer layer are usually included. These layers may be electrically conductive and formed by one or more thin films. Accordingly, the LED of the present invention can exhibit high brightness and excellent mechanical strength during manufacturing.

What is claimed is:  
     
         1 . A high brightness LED (light emitting diode), comprising: 
 a permanent substrate;    LED epitaxial layers with p-n or n-p junction;    a layered structure formed between said permanent substrate and said LED epitaxial layers, and having properties of reflection, adhesion, diffusion barrier and buffer;    a first electrode and a second electrode formed on proper positions to provide enough energy for said LED epitaxial layers.    
     
     
         2 . The high brightness LED as claimed in  claim 1 , further comprising a using-for-epitaxy substrate on said LED epitaxial layers.  
     
     
         3 . The high brightness LED as claimed in  claim 1 , wherein said layered structure comprises single layer.  
     
     
         4 . The high brightness LED as claimed in  claim 1 , wherein said layered structure comprises two layers.  
     
     
         5 . The high brightness LED as claimed in  claim 1 , wherein said layered structure comprises a reflective layer, a buffer layer and a diffusion barrier.  
     
     
         6 . The high brightness LED as claimed in  claim 5 , wherein said diffusion barrier is adjacent to said permanent substrate, said buffer layer is adjacent to said LED epitaxial layers, said reflective layer is formed between said diffusion barrier and said reflective layer, and said buffer layer is transparent.  
     
     
         7 . The high brightness LED as claimed in  claim 5 , wherein said buffer layer is adjacent to said permanent substrate, said diffusion barrier is adjacent to said LED epitaxial layers, said reflective layer is formed between said buffer layer and said diffusion barrier, and said diffusion barrier is transparent.  
     
     
         8 . The high brightness LED as claimed in  claim 5 , wherein said buffer layer is adjacent to said permanent substrate, said reflective layer is adjacent to said LED epitaxial layers, and said diffusion barrier is formed between said buffer layer and said reflective layer.  
     
     
         9 . The high brightness LED as claimed in  claim 5 , wherein said reflective layer is adjacent to said permanent substrate, said buffer layer is adjacent to said LED epitaxial layers, said diffusion barrier is formed between said buffer layer and said reflective layer, and both said diffusion barrier and said buffer layer are transparent.  
     
     
         10 . The high brightness LED as claimed in  claim 5 , wherein said diffusion barrier is adjacent to said permanent substrate, said reflective layer is adjacent to said LED epitaxial layers, and said buffer layer is formed between said diffusion barrier and said reflective layer.  
     
     
         11 . The high brightness LED as claimed in  claim 5 , wherein said reflective layer is adjacent to said permanent substrate, said diffusion barrier is adjacent to said LED epitaxial layers, said buffer layer is formed between said buffer layer and said reflective layer, and both said diffusion barrier and said buffer layer are transparent.  
     
     
         12 . The high brightness LED as claimed in  claim 5 , wherein at least one of said diffusion barrier, said buffer layer and said reflective layer is electrically conductive.  
     
     
         13 . The high brightness LED as claimed in  claim 5 , wherein said buffer layer has a thermal expansion coefficient larger than both of said using-for-epitaxy substrate and said permanent substrate.  
     
     
         14 . The high brightness LED as claimed in  claim 5 , wherein said buffer layer has a thermal expansion coefficient less than both of said using-for-epitaxy substrate and said permanent substrate.  
     
     
         15 . A method for producing a high brightness LED, comprising steps of: 
 a) providing a temporary substrate for epitaxy;    b) forming LED epitaxial layers on said temporary substrate, wherein said LED epitaxial layers with pn junction;    c) providing a permanent substrate;    d) forming a layered structure between said permanent substrate and said LED epitaxial layers, wherein said layered structure has properties of reflection, adhesion, diffusion barrier and buffer; and    e) forming a first electrode and a second electrode on proper position to supply enough energy for said LED epitaxial layers.    
     
     
         16 . The method as claimed in  claim 15 , wherein said layered structure comprises a buffer layer, a reflective layer and a diffusion barrier (in said step d).  
     
     
         17 . The method as claimed in  claim 16 , wherein said buffer layer, said reflective layer and said diffusion barrier are formed by deposition.  
     
     
         18 . The method as claimed in  claim 16 , wherein said buffer layer and said reflective layer are sequentially formed on said LED epitaxial layers, and said diffusion barrier is formed on said permanent substrate, and then said LED epitaxial layers and said permanent substrate are associated by wafer bonding technology.  
     
     
         19 . The method as claimed in  claim 16 , wherein said reflective layer is formed on said LED epitaxial layers, and said buffer layer and said diffusion barrier are sequentially formed on said permanent substrate, and then said LED epitaxial layers and said permanent substrate are associated by wafer bonding technology.  
     
     
         20 . The method as claimed in  claim 16 , wherein said diffusion barrier, said buffer layer and said reflective layer are sequentially formed on said permanent substrate, and then said LED epitaxial layers and said permanent substrate are associated by wafer bonding technology.