Gan led element and light emitting device having a structure to reduce light absorption by a pad electrode included therein

Abstract

A first conductive film 104 - 1 of a light-transmissive conductive oxide film 104 and a positive pad electrode 105 are electrically connected through a second conductive film 104 - 2 of the light-transmissive conductive oxide film 104 in a GaN-based LED element 100. A contact resistance of the light-transmissive conductive oxide film 104 with a p-type layer 102 - 3 in a first contact portion 104 A is lower than in a second contact portion 104 B, so that a current supplied from the positive pad electrode 105 to the p-type layer 102 - 3 through the conductive oxide film 104 flows to the p-type layer 102 - 3 mainly through the first contact portion 104 A.

1 . A method for producing a GaN-based LED element,
 wherein the GaN-based LED element includes:
 a semiconductor laminate composed of a plurality of GaN-based semiconductor layers, the semiconductor laminate including a p-type layer, a light emitting layer arranged on a side of one surface of the p-type layer, and an n-type layer arranged so as to sandwich the light emitting layer between the p-type layer and the n-type layer; 
 a light-transmissive conductive oxide film formed on another surface of the p-type layer; and 
 a positive pad electrode formed on the light-transmissive conductive oxide film, 
   wherein the method for producing the GaN-based LED element comprises a step of forming the light-transmissive conductive oxide film,   wherein the step of forming the light-transmissive conductive oxide film comprises:
 a first step of forming a first conductive film; and 
 a second step of forming a second conductive film on the first conductive film, and 
   wherein, in the second step, the second conductive film is partially formed on the first conductive film to serve as a convex part in a region where the light-transmissive conductive oxide is not covered with the positive pad electrode.   
     
     
         2 . The method of  claim 1 , wherein, in the second step, the second conductive film is formed into a pattern using a liftoff method to serve as the convex part in the region where the light-transmissive conductive oxide is not covered with the positive pad electrode. 
     
     
         3 . The method of  claim 1 , wherein, in the second step, the second conductive film is formed into a dot-shaped pattern to serve as the convex part in the region where the light-transmissive conductive oxide is not covered with the positive pad electrode. 
     
     
         4 . The method of  claim 1 , wherein, in the second step, the second conductive film is formed into a stripe-shaped pattern to serve as the convex part in the region where the light-transmissive conductive oxide is not covered with the positive pad electrode. 
     
     
         5 . The method of  claim 1 , wherein, in the second step, the second conductive film is formed into a net-shaped pattern to serve as the convex part in the region where the light-transmissive conductive oxide is not covered with the positive pad electrode. 
     
     
         6 . The method of  claim 1 , wherein, in the second step, a plurality of through holes are formed in the second conductive film where the light-transmissive conductive oxide film is not covered with the positive pad electrode. 
     
     
         7 . The method of  claim 1 , wherein, the light-transmissive conductive oxide film comprises one or more selected from ITO, indium oxide, tin oxide, zinc oxide, magnesium oxide, AZO, GZO, FTO, and IZO.