Semiconductor light emitting device including anode and cathode having the same metal structure
View Patent ↗A semi-conductor light emitting device 10 in the present invention comprises an n-type ZnO substrate 3 , an emission layer 2 , anode 5 , and cathode 4 . The n-type ZnO substrate 3 has a mounting surface 31 on one of its surfaces. The emission layer 2 is composed of a p-type GaN film 24 and an n-type GaN film 22 , and superimposed on the n-type ZnO substrate 3 with the p-type GaN film 24 directly disposed on the mounting surface 31 of the n-type ZnO substrate 3 . The anode 5 is disposed directly on the mounting surface 31 of the n-type GaN substrate 3 in an ohmic contact therewith and in a spaced relation from the emission layer. The cathode 4 is disposed on the n-type GaN film 22 in an ohmic contact therewith. The cathode 4 and anode 5 are of the same structure solely composed of a metallic material. The semi-conductor light emitting device in the present invention assures good ohmic contact of both the cathode 4 and the anode 5 , and minimizes consumption of metallic materials.
1. A semi-conductor light emitting device comprising:
an n-type ZnO substrate having a mounting surface;
a light emission layer composed of a p-type GaN film and an n-type GaN film superimposed on said p-type GaN film, said light emission layer being superimposed on said n-type ZnO substrate with said p-type GaN film directly disposed on said mounting surface of said n-type ZnO substrate;
an anode disposed directly on said mounting surface of said n-type ZnO substrate in an ohmic contact therewith and in a spaced relation from said light emission layer; and
a cathode disposed on said n-type GaN film in an ohmic contact therewith, wherein:
said anode and said cathode are of the same structure solely composed of a metallic material,
each of said anode and said cathode is made of a metal laminate, and
said anode is disposed directly on said mounting surface, and said cathode is disposed on said mounting surface through said light emission layer such that said p-type GaN film of said light emission layer is disposed directly on said mounting surface.
2. The semiconductor light emitting device as set forth in claim 1 , wherein:
each of said cathode and said anode is made of a metal laminate composed of a first metal film and a second metal film,
said first metal film of said anode forms direct ohmic contact with said n-type ZnO substrate, and
said first metal film of said cathode forms direct ohmic contact with said n-type GaN film of the light emission layer.
3. The semiconductor light emitting device as set forth in claim 1 , wherein:
said metal laminate is selected from a group consisting of:
a laminate composed of a Ti film, an Au film, and an Al film interposed therebetween;
a laminate composed of a Ti film and an Au film;
a laminate composed of an Al film and an Au film; and
a laminate composed of a Ti film, an Al film, a Ni film, and an Au film laminated in this order.