Method of fabricating a light emitting diode device

Abstract

The present invention relates to a light emitting diode (LED) and a flip-chip packaged LED device. The present invention provides an LED device. The LED device is flipped on and connected electrically with a packaging substrate and thus forming the flip-chip packaged LED device. The LED device mainly has an Ohmic-contact layer and a planarized buffer layer between a second-type doping layer and a reflection layer. The Ohmic-contact layer improves the Ohmic-contact characteristics between the second-type doping layer and the reflection layer without affecting the light emitting efficiency of the LED device and the flip-chip packaged LED device. The planarized buffer layer id disposed between the Ohmic-contact layer and the reflection layer for smoothening the Ohmic-contact layer and hence enabling the reflection layer to adhere to the planarized buffer layer smoothly. Thereby, the reflection layer can have the effect of mirror reflection and the scattering phenomenon on the reflected light can be reduced as well.

1 . A method of fabricating a light emitting diode device, comprising:
 sequentially forming a first-type doping layer, a light emitting layer and a second-type doping layer on a substrate;   forming an Ohmic-contact layer on the second-type doping layer;   forming a material layer and a metal layer on the Ohmic-contact layer, wherein the material layer at least comprises a metal oxide layer; and   forming a first electrode and a second electrode the first-type doping layer and the metal layer respectively, wherein the first electrode is electrically connected to the first-type doping layer and the second electrode is electrically connected to the Ohmic-contact layer through the metal layer.   
     
     
         2 . The method of  claim 1 , wherein a light transmittance of the Ohmic-contact layer is greater than 90%. 
     
     
         3 . The method of  claim 1 , wherein a light transmittance of the material layer is greater than 95%. 
     
     
         4 . The method of  claim 1  further comprising:
 forming a cover layer, wherein the cover layer is disposed on the metal layer and extends to a sidewall of the metal layer. 
 
     
     
         5 . The method of  claim 1 , wherein a portion of the light emitted from the light emitting layer passes through the Ohmic-contact layer as well as the material layer and is reflected by the metal layer. 
     
     
         6 . A method of fabricating a light emitting diode device, comprising:
 sequentially forming a first-type doping layer, a light emitting layer and a second-type doping layer on a substrate;   forming an Ohmic-contact layer on the second-type doping layer;   forming an oxide stacking layer and a metal reflection layer on the Ohmic-contact layer, wherein the oxide stacking layer comprises a plurality of stacked oxide layers; and   forming a first electrode and a second electrode the first-type doping layer and the metal reflection layer respectively, wherein the first electrode is electrically connected to the first-type doping layer, the second electrode is electrically connected to the Ohmic-contact layer, and the oxide stacking layer and the metal reflection layer are disposed between the second electrode and the Ohmic-contact layer.   
     
     
         7 . The method of  claim 6 , wherein a light transmittance of the Ohmic-contact layer is greater than 90%. 
     
     
         8 . The method of  claim 6  further comprising:
 forming a cover layer, wherein the cover layer is disposed between the metal reflection layer and the second electrode. 
 
     
     
         9 . The method of  claim 6 , wherein a portion of the light emitted from the light emitting layer passes through the Ohmic-contact layer and is reflected by the metal reflection layer. 
     
     
         10 . A method of fabricating a light emitting diode device, comprising:
 sequentially forming a first-type doping layer, a light emitting layer and a second-type doping layer on a substrate;   forming an Ohmic-contact layer on the second-type doping layer;   forming an oxide stacking layer and a metal reflection layer on the Ohmic-contact layer, wherein the oxide stacking layer comprises a plurality of stacked oxide layers; and   forming a first electrode and a second electrode the first-type doping layer and the metal reflection layer respectively, wherein the first electrode is electrically connected to the first-type doping layer, the oxide stacking layer and the metal reflection layer are disposed between the second electrode and the Ohmic-contact layer, and the second electrode is electrically connected to the Ohmic-contact layer through the metal reflection layer.   
     
     
         11 . The method of  claim 10 , wherein a light transmittance of the Ohmic-contact layer is greater than 90%. 
     
     
         12 . The method of  claim 10  further comprising:
 forming a cover layer, wherein the cover layer is disposed between the metal reflection layer and the second electrode. 
 
     
     
         13 . The method of  claim 10 , wherein a portion of the light emitted from the light emitting layer passes through the Ohmic-contact layer and is reflected by the metal reflection layer. 
     
     
         14 . A method of fabricating a light emitting diode device, comprising:
 sequentially forming a first-type doping layer, a light emitting layer and a second-type doping layer on a substrate;   forming an Ohmic-contact layer on the second-type doping layer;   forming a metal reflection layer and at least one oxide layer on the Ohmic-contact layer, wherein the at least one oxide layer is disposed between the Ohmic-contact layer and the metal reflection layer; and   forming a first electrode and a second electrode the first-type doping layer and the metal reflection layer respectively, wherein the first electrode is electrically connected to the first-type doping layer, the second electrode is electrically connected to the Ohmic-contact layer, and the metal reflection layer disposed between the second electrode and the Ohmic-contact layer.   
     
     
         15 . The method of  claim 14 , wherein a light transmittance of the Ohmic-contact layer is greater than 90%. 
     
     
         16 . The method of  claim 14 , wherein a light transmittance of the oxide layer is greater than 95%. 
     
     
         17 . The method of  claim 14  further comprising:
 forming a cover layer, wherein the cover layer is disposed between the metal reflection layer and the second electrode. 
 
     
     
         18 . The method of  claim 14 , wherein a portion of the light emitted from the light emitting layer passes through the Ohmic-contact layer as well as the oxide layer and is reflected by the metal reflection layer. 
     
     
         19 . A method of fabricating a light emitting diode device, comprising:
 sequentially forming a first-type doping layer, a light emitting layer and a second-type doping layer on a substrate;   forming an Ohmic-contact layer on the second-type doping layer;   forming a metal reflection layer and at least one oxide layer on the Ohmic-contact layer; and   forming a first electrode and a second electrode the first-type doping layer and the metal reflection layer respectively, wherein the first electrode is electrically connected to the first-type doping layer, the metal reflection layer and the at least one oxide layer are disposed between the second electrode and the Ohmic-contact layer, and the second electrode is electrically connected the Ohmic-contact layer through the metal reflection layer.   
     
     
         20 . The method of  claim 19 , wherein a light transmittance of the Ohmic-contact layer is greater than 90%. 
     
     
         21 . The method of  claim 19 , wherein a light transmittance of the oxide layer is greater than 95%. 
     
     
         22 . The method of  claim 19  further comprising:
 forming a cover layer, wherein the cover layer is disposed between the metal reflection layer and the second electrode. 
 
     
     
         23 . The method of  claim 19 , wherein a portion of the light emitted from the light emitting layer passes through the Ohmic-contact layer and is reflected by the metal reflection layer. 
     
     
         24 . A method of fabricating a light emitting diode device, comprising:
 sequentially forming a first-type doping layer, a light emitting layer and a second-type doping layer on a substrate;   forming an Ohmic-contact layer on the second-type doping layer;   forming a material stacking layer on the Ohmic-contact layer, wherein the material stacking layer comprises a plurality of first material layers and a plurality of second material layers alternately stacked, and light transmittance of the first material layers differs from light transmittance of the second material layers; and   forming a first electrode and a second electrode the first-type doping layer and the material stacking layer respectively, wherein the first electrode is electrically connected to the first-type doping layer, the second electrode is electrically connected to the Ohmic-contact layer, and the material stacking layer is disposed between the second electrode and the Ohmic-contact layer.   
     
     
         25 . The method of  claim 24 , wherein a light transmittance of the Ohmic-contact layer is greater than 90%. 
     
     
         26 . The method of  claim 24  further comprising:
 forming a metal layer disposed between the second electrode and the Ohmic-contact layer. 
 
     
     
         27 . The method of  claim 26 , wherein a portion of the light emitted from the light emitting layer passes through the Ohmic-contact layer and is reflected by the metal layer.