Light-emitting device and the manufacturing method thereof

Abstract

A light-emitting device, comprising: a substrate comprising an upper surface; an ion implantation region in the substrate; a semiconductor layer formed on the upper surface; a light-emitting stack formed on the semiconductor layer; and multiple cavities formed between the semiconductor layer and the upper surface in accordance with the ion implantation region.

What is claimed is: 
     
         1 . A light-emitting device, comprising:
 a substrate comprising an upper surface;   an ion implantation region in the substrate;   a semiconductor layer formed on the upper surface;   a light-emitting stack formed on the semiconductor layer; and   multiple cavities formed between the semiconductor layer and the upper surface in accordance with the ion implantation region.   
     
     
         2 . The light-emitting device according to  claim 1 , wherein the upper surface comprises a concave portion. 
     
     
         3 . The light-emitting device according to  claim 2 , wherein the ion implantation region overlaps with the concave portion. 
     
     
         4 . The light-emitting device according to  claim 1 , wherein the upper surface comprises multiple protrusions periodically arranged over the upper surface. 
     
     
         5 . The light-emitting device according to  claim 4 , wherein one of the multiple protrusions comprises multiple micro-protrusions randomly arranged over the one protrusion. 
     
     
         6 . The light-emitting device according to  claim 5 , wherein the multiple micro-protrusions are separated from each other by the concave portion. 
     
     
         7 . The light-emitting device according to  claim 1 , wherein the substrate comprises a single-crystalline material and the light-emitting stack comprises nitride based semiconductor. 
     
     
         8 . The light-emitting device according to  claim 5 , wherein the cavities and the micro-protrusions are formed alternately. 
     
     
         9 . The light-emitting device according to  claim 5 , wherein the shapes of the multiple protrusions are substantially the same, and the shapes of the multiple micro-protrusions are substantially different. 
     
     
         10 . The light-emitting device according to  claim 1 , wherein one of the cavities has a feature size smaller than 1 μm. 
     
     
         11 . A method of manufacturing a light-emitting device, comprising the steps of:
 providing a substrate;   forming a mask block on the substrate and exposing a portion of the substrate;   implanting an ion into the portion of the substrate to form an ion implantation region; and   growing a semiconductor stack on the substrate such that multiple cavities are formed between the semiconductor stack and the ion implantation region.   
     
     
         12 . The method of manufacturing a light-emitting device according to  claim 11 , further comprising a step of removing the mask block. 
     
     
         13 . The method of manufacturing a light-emitting device according to  claim 11 , wherein the mask block comprises a material made of metal or oxide. 
     
     
         14 . The method of manufacturing a light-emitting device according to  claim 13 , wherein the step of forming the mask block comprises forming a metal film on the substrate and applying a heat treatment to the metal film to form multiple metal particles separated from each other. 
     
     
         15 . The method of manufacturing a light-emitting device according to  claim 14 , wherein a thickness of the metal film is smaller than  100 nm. 
     
     
         16 . The method of manufacturing a light-emitting device according to  claim 14 , wherein a particle size of one of the multiple metal particles is between 50 nm and 500 nm, and a gap between neighboring two of the metal particles is smaller than 1 μm. 
     
     
         17 . The method of manufacturing a light-emitting device according to  claim 14  further comprising a step of forming an oxide layer on the substrate before forming the metal film on the substrate. 
     
     
         18 . The method of manufacturing a light-emitting device according to  claim 17 , wherein a thickness of the oxide layer is smaller than 500 nm. 
     
     
         19 . The method of manufacturing a light-emitting device according to  claim 13 , wherein the step of forming the mask block comprises disposing multiple oxide particles on the substrate, wherein a particle size of one of the multiple oxide particles between 300 nm and 600 nm, and a gap between neighboring two of the oxide particles is smaller than 1 μm. 
     
     
         20 . The method of manufacturing a light-emitting device according to  claim 11 , further comprising a step of etching the portion of the substrate to form a concave region in the substrate.