Gallium nitride semiconductor light emitting device and method of manufacturing the same

Abstract

Disclosed herein are a gallium nitride semiconductor LED (light emitting device) and a method of manufacturing the same, which reduces defects, such as Ga vacancies and dislocations caused by lattice mismatching, with Al doping, so that electrical and an optical properties are enhanced. The gallium nitride semiconductor LED comprises a substrate for growing a GaN semiconductor material, an n-type GaN clad layer formed on the substrate and doped with Al, an active layer having a quantum well structure formed on the n-type GaN clad layer, and a p-type GaN clad layer formed on the active layer. By the above method, good quality crystal growth is ensured with a low cost and the GaN semiconductor LED of excellent electrical and optical properties is provided.

1 . A gallium nitride (GaN) semiconductor light emitting device for a flip chip, the GaN light emitting device comprising: 
 a substrate for growing a GaN semiconductor material;    an n-type GaN clad layer formed on the substrate and doped with Al;    an active layer having a quantum well structure formed on 10 the n-type GaN clad layer; and    a p-type GaN clad layer formed on the active layer.    
   
   
       2 . The GaN semiconductor light emitting device as set forth in  claim 1 , wherein the n-type GaN clad layer is doped with Al in a content of 0.01%˜1%.  
   
   
       3 . The GaN semiconductor light emitting device as set forth in  claim 1 , further comprising: 
 a buffer layer formed between the substrate and the n 20 type GaN clad layer.    
   
   
       4 . The GaN semiconductor light emitting device as set for  claim 3 , wherein the buffer layer comprises an Al seed layer formed on the substrate layer and a single crystal AlN layer formed on the Al seed layer.  
   
   
       5 . The GaN semiconductor light emitting device as set forth in  claim 4 , wherein the single crystal AlN layer has a thickness of 10 nm˜50 nm.  
   
   
       6 . The GaN semiconductor light emitting device as set forth in  claim 3 , wherein the buffer layer is a non-crystalline AIN layer or a non-crystalline GaN layer.  
   
   
       7 . The GaN semiconductor light emitting device as set forth in  claim 3 , further comprising: 
 a GaN interlayer formed between the buffer layer and the n-type GaN clad layer.    
   
   
       8 . The GaN semiconductor light emitting device as set forth in  claim 7 , wherein the GaN interlayer has a thickness of 100 nm˜1 μm.  
   
   
       9 . The GaN semiconductor light emitting device as set forth in  claim 7 , further comprising: 
 an Al-doped GaN layer formed between the GaN interlayer and the n-type gaN clad layer.    
   
   
       10 . The GaN semiconductor light emitting device as set forth in  claim 9 , wherein the Al-doped GaN layer is doped with Al in a content of 0.01% 1%.  
   
   
       11 . The GaN semiconductor light emitting device as set forth in  claim 9 , wherein the Al-doped GaN layer has a thickness of 1 μm ˜4 μm.  
   
   
       12 . A method of manufacturing a GaN semiconductor light emitting device comprising the steps of: 
 a) preparing a substrate for growing a GaN semiconductor material;    b) forming an n-type GaN clad layer doped with Al on the 10 substrate;    c) forming an active layer having a quantum well structure on the n-type GaN clad layer; and    d) forming a p-type GaN clad layer on the active layer.    
   
   
       13 . The method as set forth in  claim 12 , wherein the step b) comprises the step of forming an n-type GaN clad layer doped with Al in a content of 0.01%-1%.  
   
   
       14 . The method as set forth in  claim 12 , the method further comprising the step of: 
 e) forming a buffer layer on the substrate before the step b).    
   
   
       15 . The method as set forth in  claim 14 , wherein the step e) comprises the steps of: 
 e-1) forming an Al seed layer on the substrate layer; and    e-2) forming a single crystal AIN layer on the Al seed layer.    
   
   
       16 . The method as set forth in  claim 15 , wherein the step e-2) comprises the step of forming a single crystal AlN layer at a high temperature of 1,000° C.˜1,100° C. using an MOCVD process.  
   
   
       17 . The method as set forth in  claim 15  [[or  16 ]], wherein the step e-2) comprises the step of forming a single crystal AlN layer with a thickness of 10 nm ˜50 nm.  
   
   
       18 . The method as set forth in  claim 14 , wherein the step e) comprises the step of forming a non-crystalline AlN layer on the substrate or the step of forming a non-crystalline GaN layer on the substrate.  
   
   
       19 . The method as set forth in  claim 14 , the method further comprising the step of: 
 f) forming a GaN interlayer on the buffer layer before the step b).    
   
   
       20 . The method as set forth in  claim 19 , wherein the step f) comprises the step of forming a GaN interlayer with a thickness of 100 nm˜1 μm.  
   
   
       21 . The method as set forth in  claim 19 , the method further comprising the step of: 
 g) forming an Al-doped GaN layer on the GaN interlayer before the step b).    
   
   
       22 . The method as set forth in  claim 21 , wherein the step g) comprises the step of forming a GaN layer doped with Al in 10 a content of 0.01%˜1%.  
   
   
       23 . The method as set forth in claim, wherein the step g) comprises the step of forming a GaN layer with a thickness of 1 μm˜4 μm.  
   
   
       24 . The method as set forth in  claim 12 , further comprising the steps of: 
 e) removing a predetermined portion of the active layer and p-type clad layer to expose a predetermined portion of the n-type clad layer;    f) forming a p-metal layer on the p-type clad layer; and    g) forming a p-side bonding electrode and an n-side electrode on the p-metal layer and on the exposed portion of the n-type clad GaN layer, respectively.