GaN-based light emitting-diode chip and a method for producing same

Abstract

An LED chip comprising an electrically conductive and radioparent substrate, in which the epitaxial layer sequence is provided on substantially the full area of its p-side with a reflective, bondable p-contact layer. The substrate is provided on its main surface facing away from the epitaxial layer sequence with a contact metallization that covers only a portion of said main surface, and the decoupling of light from the chip takes place via a bare region of the main surface of the substrate and via the chip sides. A further LED chip has epitaxial layers only. The p-type epitaxial layer is provided on substantially the full area of the main surface facing away from the n-conductive epitaxial layer with a reflective, bondable p-contact layer, and the n-conductive epitaxial layer is provided on its main surface facing away from the p-conductive epitaxial layer with an n-contact layer that covers only a portion of said main surface. The decoupling of light from the chip takes place via the bare region of the main surface of the n-conductive epitaxial layer and via the chip sides.

1 . A light-emitting diode chip, comprising: 
 a GaN-based radiation-emitting epitaxial layer sequence comprising an n-type epitaxial layer and a p-type epitaxial layer;    a reflective, bondable p-contact layer reflective of radiation emitted by the epitaxial layer sequence and disposed on a surface of the p-type epitaxial layer that is oriented away from the n-type epitaxial layer, said p-contact layer comprising a PtAg alloy and/or a PdAg alloy; and    a contact metallization disposed over only a portion of a surface of the light-emitting diode chip facing away from said surface of the p-type epitaxial layer.    
   
   
       2 . The light-emitting diode chip as recited in  claim 1 , wherein a growth substrate is positioned on the epitaxial layer sequence facing away from said surface of the p-type epitaxial layer and wherein the radiation emitted by the epitaxial layer is decoupled out of the light-emitting diode chip through at least one surface of the growth substrate.  
   
   
       3 . The light-emitting diode chip as recited in  claim 2 , wherein said growth substrate is electrically conductive.  
   
   
       4 . The light-emitting diode chip as recited in  claim 2 , wherein the substrate is thinned.  
   
   
       5 . The light-emitting diode chip as recited in  claim 3 , wherein the electrically conductive substrate is a silicon carbide substrate.  
   
   
       6 . The light-emitting diode chip as recited in  claim 1 , wherein the chip does not include a growth substrate.  
   
   
       7 . The light-emitting diode chip as recited in  claim 1 , wherein the entire bare surface of, or a subarea of, the layer sequence is roughened.  
   
   
       8 . The light-emitting diode chip as claimed in  claim 1 , wherein the reflective, bondable p-contact layer is provided on substantially the full area of said surface of the p-type epitaxial layer.  
   
   
       9 . The light-emitting diode chip as recited in  claim 1 , wherein said p-contact layer comprises a first layer transmissive of radiation emitted by the epitaxial layer sequence and a second layer reflective of radiation emitted by the epitaxial layer sequence and disposed on the first layer.  
   
   
       10 . The light-emitting diode chip as recited in  claim 9 , wherein the first layer of the reflective, bondable p-contact layer comprises Pt and/or Pd and the second layer of the reflective, bondable p-contact layer is realized as a dielectric mirror.  
   
   
       11 . The light-emitting diode chip as recited in  claim 9 , wherein the first layer of the reflective, bondable p-contact layer comprises Pt and/or Pd and the second layer of the reflective, bondable p-contact layer comprises Ag, Au and/or Al.  
   
   
       12 . The light-emitting diode chip as recited in  claim 1 , wherein the surface of the light emitting diode chip through which the radiation is decoupled is roughened.  
   
   
       13 . The light-emitting diode chip as recited in  claim 1 , wherein the radiation emitted by the epitaxial layer is decoupled out of the light-emitting diode chip through a top surface of the light emitting diode chip facing away from said surface of the p-type epitaxial layer.  
   
   
       14 . The light-emitting diode chip as recited in  claim 1 , wherein the radiation emitted by the epitaxial layer is further decoupled out of the light-emitting diode chip through at least one side surface of the light emitting diode chip.  
   
   
       15 . The light-emitting diode chip as recited in  claim 2 , wherein the radiation emitted by the epitaxial layer is decoupled out of the light-emitting diode chip through multiple surfaces of the growth substrate.