Method for fabricating submicron patterned sapphire substrate

Abstract

The present invention provides a method for fabricating a submicron patterned sapphire substrate to be able to apply in GaN light emitting diode. The method includes the following steps: forming an etching stop layer on a sapphire substrate; forming a photoresist layer on the etching stop layer; making a photo mask to contact with the photoresist layer; illuminating the photoresist layer with a beam of light by using the photo mask, and developing the photoresist layer to transfer a submicron pattern from the photo mask to the photoresist layer; etching the etching stop layer by using the photoresist layer with the submicron pattern as a mask to form a first etching stop layer; and etching the sapphire substrate with the first etching stop layer to acquire a submicron patterned sapphire substrate.

1 . A method for fabricating a submicron patterned sapphire substrate, the method comprises the following procedures:
 forming an etching stop layer on a sapphire substrate;   forming a photoresist layer on the etching stop layer;   contacting the photoresist layer with a photo mask having the submicron pattern;   illuminating the photoresist layer with a beam of light through the photo mask, and developing the photoresist layer to transfer the submicron pattern from the photo mask to the photoresist layer;   etching the etching stop layer by using the photoresist layer with the submicron pattern as a mask to form a first etching stop layer; and   etching the sapphire substrate with the first etching stop layer to acquire the submicron patterned sapphire substrate.   
     
     
         2 . The method according to  claim 1 , further comprising the following step:
 contacting said photoresist layer with the photo mask after soft-baking the photoresist layer.   
     
     
         3 . The method according to  claim 1 , wherein said beam of light is an ultraviolet light. 
     
     
         4 . The method according to  claim 1 , further comprising the following step:
 removing said photoresist layer after forming the first etching stop layer.   
     
     
         5 . The method according to  claim 4 , further comprising the following step:
 etching said sapphire substrate having the first etching stop layer by using a wet etching process.   
     
     
         6 . The method according to  claim 1 , further comprising the following step:
 a block structure is formed with said etching stop layer and said photoresist layer with the submicron structure, after forming said first etching stop layer.   
     
     
         7 . The method according to  claim 6 , further comprising the following procedure:
 etching said sapphire substrate having said block structure by using a dry etching process.   
     
     
         8 . The method according to  claim 1 , wherein said etching stop layer is formed on said substrate with physical vapor deposition process. 
     
     
         9 . The method according to  claim 1 , wherein said etching stop layer is formed on said substrate with chemical vapor deposition process. 
     
     
         10 . The method according to  claim 1 , wherein said photoresist layer is formed on said etching stop layer with spin coating process. 
     
     
         11 . A method of fabricating a submicron patterned sapphire substrate, the method comprising the following procedures:
 fabricating a master mold, wherein the master mold having a submicron pattern;   pouring and filling a flexible material into said master mold to shape a sub-mold, the sub-mold having a counterpart pattern to said submicron pattern of the master mold;   pouring and filling an imprinting material into said counterpart pattern of said sub-mold;   imprinting a sapphire substrate with said sub-mold, and then building said imprinting material on said sapphire substrate to form a photoresist layer, said photoresist layer having said submicron pattern; and   performing an etching process to said sapphire substrate by using said photoresist layer as a mask to acquire said submicron patterned sapphire substrate.   
     
     
         12 . The method according to  claim 11 , wherein said sapphire substrate further comprising an etching stop layer and said photoresist layer is set upon said etching stop layer, the method further comprising the following steps:
 etching said etching stop layer by using said photoresist layer with said submicron pattern as a first mask to transfer said submicron pattern to said etching stop layer; and   performing said etching process to said sapphire substrate by using said etching stop layer with said submicron structure as a second mask to acquire said submicron patterned sapphire substrate.   
     
     
         13 . The method according to  claim 12 , further comprising the following step:
 removing said photoresist layer after transferring said submicron pattern to said etching stop layer.   
     
     
         14 . The method according to  claim 11 , further comprising the following step:
 performing a wet etching process to said sapphire substrate to acquire said submicron patterned sapphire substrate.   
     
     
         15 . The method according to  claim 11 , further comprising the following step:
 performing a dry etching process to said sapphire substrate to acquire said submicron patterned sapphire substrate.   
     
     
         16 . The method according to  claim 11 , further comprising the following step:
 using an electron beam lithography process to fabricate said master mold.   
     
     
         17 . The method according to  claim 11 , further comprising the following step:
 Using an exposure process and an etching process to fabricate said master mold.