Light-emitting semiconductor device having enhanced brightness

Abstract

This invention this invention provides a light-emitting semiconductor device having enhanced brightness, to ensure even current distribution emitted by a front contact of the light emitting diodes so as to improve the light-emitting efficiency of the active layer. This invention adopts the method to manufacture the light-emitting device, comprising the steps of: forming an active layer on a substrate; forming a capping layer on the active layer to enhance current distribution, where a back contact is located on another side of the substrate and a front contact is located above the capping layer. This invention is characterized by: re-designing the front contact, by reducing the width of a metallic pattern constructing fingers or Mesh lines and increasing the number of the fingers or Mesh lines, so as to resolve the current crowding problem.

What is claimed is: 
     
       1. A light-emitting semiconductor device having enhanced brightness, comprising:
 (a) a semiconductor substrate; 
 (b) an active layer located above the semiconductor substrate, for inducing illumination of emitting light; 
 (c) a conductive back contact located below capping layer formed on the semiconductor substrate active layer; and 
 (d) a conductive front contact located above the active layer, the front contact including a an ohmic contact metallic bonding pad and ohmic contact mesh pattern having a minimum dimension ranging line width between about 0.1 and 5 to 4 micrometers and distributed above the active formed on the capping layer, and 
 (e) a bonding pad arranged on top of the ohmic contact metallic mesh pattern, 
 wherein the ohmic contact metallic mesh pattern interconnects with the bonding pad. 
 
     
     
       2. The light-emitting semiconductor device having enhanced brightness of  claim 1 , wherein the semiconductor substrate is comprises GaAs. 
     
     
       3. The light-emitting semiconductor device having enhanced brightness of claim  2  1, wherein the active layer is comprises AlGaInP or AlGaAs. 
     
     
       4. The light-emitting semiconductor device having enhanced brightness of  claim 2 , wherein the active layer is AlGaAs. 
     
     
       5. The light-emitting semiconductor device having enhanced brightness of  claim 1 , wherein the semiconductor substrate is comprises sapphire. 
     
     
       6. The light-emitting semiconductor device having enhanced brightness of claim  4  1, wherein the active layer is comprises AlGaInN. 
     
     
       7. The light-emitting semiconductor device having enhanced brightness of  claim 1 , wherein the ohmic contact metallic patterns of the front contact mesh pattern is configured to an interconnected mesh and in electrical connection with the metallic bonding pad pattern. 
     
     
       8. The light-emitting semiconductor device having enhanced brightness of  claim 7 , wherein the metallic patterns of the front contact are embedded and interconnected in an ITO layer. 
     
     
       9. A light-emitting device having enhanced brightness, comprising:
 (a) a substrate;   (b) an active layer located above the substrate, for inducing illumination of light;   (c) a back contact located below the substrate; and   (d) a front contact located above the active layer, the front contact including a metallic bonding pad and ohmic contact metallic patterns, the metallic patterns of the front contact having a minimum dimension ranging between 0.1 and 5 micrometers and distributed above the active layer.   
     
     
       10. The light-emitting semiconductor device of claim 1, wherein the line width of the metallic mesh pattern is less than 1 micrometers. 
     
     
       11. The light-emitting semiconductor device of claim 1, wherein the capping layer comprises one material selected from the group consisting of GaP, AlGaAs, and ITO. 
     
     
       12. A light-emitting semiconductor device comprising:
 (a) a substrate;   (b) an active layer located above the substrate for emitting light;   (c) a capping layer formed on the active layer;   (d) an ohmic contact metallic mesh pattern having a line width between about 0.1 to 1 micrometer formed on the capping layer; and   (e) a bonding pad arranged on top of the ohmic contact metallic mesh pattern,   wherein the ohmic contact metallic mesh pattern interconnects with the bonding pad.   
     
     
       13. The light-emitting semiconductor device of claim 1, wherein the ohmic contact metallic mesh pattern comprises a plurality of equal-distance metallic lines. 
     
     
       14. The light-emitting semiconductor device of claim 1, further comprising:
 an ITO layer formed between the capping layer and the bonding pad, the ohmic contact metallic mesh pattern being embedded in the ITO layer.   
     
     
       15. The light-emitting semiconductor device of claim 1, wherein the ohmic contact metallic pattern is in a form selected from the group consisting of a number of fingers and meshes. 
     
     
       16. The light-emitting semiconductor device of claim 1, wherein the ohmic contact metallic pattern is evenly distributed above the substrate.