Semiconductor light emitting device

Abstract

According to one embodiment, in a semiconductor light emitting device, a first electrode is provided on a first surface of the semiconductor laminated body including a light emitting layer. A joint metal layer is provided on a second surface of the semiconductor laminated body opposed to the first surface of the semiconductor laminated body. A bonding metal layer covers a first surface of the joint metal layer on a side opposite to the semiconductor laminated body and is provided on a side of the second surface of the semiconductor laminated body. A substrate provided with a second electrode is bonded to the bonding metal layer. A layer having an etching resistance property to an etchant for etching the semiconductor laminated body is formed on a side of the surface of the bonding metal layer facing to the semiconductor laminated body.

What is claimed is: 
     
         1 . A semiconductor light emitting device comprising:
 a semiconductor layer including a light emitting layer, the semiconductor layer having a first surface at which light from the light emitting layer is output and a second surface opposite the first surface;   a first metal layer having a third surface contacting a first portion of the second surface of the semiconductor layer and a fourth surface opposite the third surface, and a first sidewall connecting the third and fourth surfaces;   a second metal layer provided on a substrate and directly contacting a second portion of the second surface of the semiconductor layer, the fourth surface of the first metal layer, the second portion of the second surface being adjacent to the first portion, the second metal layer being provided between the semiconductor layer and the substrate; and   a first electrode provided on the first surface of the semiconductor layer, wherein   the first metal layer is between the second metal layer and the first portion of the second surface of the semiconductor layer, and   a width of the semiconductor layer along a direction parallel to the second surface increases from the first surface to the second surface.   
     
     
         2 . The device of  claim 1 , wherein a total area of the first metal layer facing the semiconductor layer is less than a total area of the semiconductor layer facing the substrate. 
     
     
         3 . The device of  claim 2 , wherein the second metal layer directly contacts the first sidewall of the first metal layer and the fourth surface of the first metal layer. 
     
     
         4 . The device of  claim 1 , wherein the first metal layer directly contacts the first portion of the second surface of the semiconductor layer, and the second portion encircles the first portion in a plane of the second surface. 
     
     
         5 . The device of  claim 1 , wherein the second metal layer includes a nickel layer, a titanium layer, a platinum layer, and a gold layer, which are laminated in this order along a direction from the first surface of the semiconductor layer toward the substrate. 
     
     
         6 . The device of  claim 1 , wherein the first metal layer is a silver layer. 
     
     
         7 . The device of  claim 1 , wherein the second metal layer includes a nickel layer or a platinum layer. 
     
     
         8 . The device of  claim 1 , wherein the first metal layer is embedded in the semiconductor layer such that the fourth surface of the first metal layer that is in contact with the second metal layer is in a same plane with the second portion of the second surface of the semiconductor layer.