Substrate-free flip chip light emitting diode

Abstract

A substrate-free LED device is provided. The LED device comprises a substrate, an epitaxial layer disposed on the substrate, a first electrode disposed on a portion of the epitaxial layer, a second electrode disposed on another portion of the epitaxial layer, and a protection layer, disposed over the epitaxial layer. It is noted that in the LED device, the substrate comprises, for example but not limited to, high heat-sink substrate, and the protection layer comprises, for example but not limited to, high heat-sink, high transparent material.

1 . A light emitting diode (LED) device, comprising:
 a substrate;   an epitaxial layer, disposed on the substrate;   a first electrode, disposed on a portion of the epitaxial layer;   a second electrode, disposed on another portion of the epitaxial layer; and   a protection layer, disposed over the epitaxial layer;   wherein the substrate comprises high heat-sink substrate, and the protection layer comprises high heat-sink, high transparent material.   
     
     
         2 . The LED device of  claim 1 , wherein a material of the epitaxial layer comprises two-element compound semiconductor. 
     
     
         3 . The LED device of  claim 2 , wherein the two-element compound semiconductor comprises GaN, GaAs, or InN. 
     
     
         4 . The LED device of  claim 1 , wherein a material of the epitaxial layer comprises three-element compound semiconductor. 
     
     
         5 . The LED device of  claim 4 , wherein the three-element compound semiconductor comprises GaAlAs. 
     
     
         6 . The LED device of  claim 1 , wherein a material of the epitaxial layer comprises four-element compound semiconductor. 
     
     
         7 . The LED device of  claim 6 , wherein the four-element compound semiconductor comprises AlInGaP. 
     
     
         8 . The LED device of  claim 1 , wherein a thickness of the another portion of the epitaxial layer is less than a thickness of a current distribution layer of the epitaxial layer, and the second electrode is connected to the current distribution layer of the epitaxial layer. 
     
     
         9 . The LED device of  claim 1 , wherein the current distribution layer is P-type, the first electrode comprises N-type ohmic contact electrode, and the second electrode comprises P-type ohmic contact electrode. 
     
     
         10 . The LED device of  claim 1 , wherein the current distribution layer is N-type, the first electrode comprises P-type ohmic contact electrode, and the second electrode comprises N-type ohmic contact electrode. 
     
     
         11 . The LED device of  claim 1 , wherein a total thickness of the first electrodes and the portion of the epitaxial layer is equal to a total thickness of the second electrode and the another portion of the epitaxial layer. 
     
     
         12 . The LED device of  claim 1 , wherein a material of the high heat-sink silicon substrate comprises silicon or ceramic. 
     
     
         13 . The LED device of  claim 1 , wherein a material of the high heat-sink, high transparent material comprises diamond-like carbon (DLC), silicon oxide (SiO 2 ) or silicon nitride (SiN x ).