Light emitting diode having vertical topology and method of making the same

Abstract

A light emitting device can include a supporting layer; a semiconductor structure including: an active layer between first-type and second-type semiconductor layers, a first top surface and a first bottom surface, and a side surface between the first top and bottom surfaces, which is inclined; a first electrode between the supporting and semiconductor layers; a connection metal layer having a first portion between the first electrode and the supporting layer, which includes a stepped portion having a upper portion contacting the first electrode, and a second portion of the connection metal layer extends beyond the semiconductor structure; and a passivation layer extending from the second portion of the connection metal layer to the side surface of the semiconductor structure, which includes a second bottom surface contacting the second portion of the connection metal layer; and a second top surface opposite to the second bottom surface.

What is claims is: 
     
         1 . A light emitting device, comprising:
 a supporting layer;   a semiconductor structure including a first-type semiconductor layer, a second-type semiconductor layer, and an active layer between the first-type semiconductor layer and the second-type semiconductor layer, wherein the semiconductor structure further comprises:
 a first bottom surface proximate to the supporting layer, 
 a first top surface opposite to the first bottom surface, and 
 a side surface between the first top surface and the first bottom surface, the side surface being inclined with reference to the first bottom surface of the semiconductor structure; 
   a first electrode disposed between the supporting layer and the semiconductor layer;   a connection metal layer having a first portion disposed between the first electrode and the supporting layer, wherein the first portion of the connection metal layer comprises a stepped portion, wherein the stepped portion has a upper portion that is in contact with the first electrode, and wherein a second portion of the connection metal layer extends beyond the semiconductor structure; and   a passivation layer extending from the second portion of the connection metal layer to the side surface of the semiconductor structure,   wherein the passivation layer comprises:
 a second bottom surface in contact with the second portion of the connection metal layer; and 
 a second top surface opposite to the second bottom surface. 
   
     
     
         2 . The light emitting device according to  claim 1 , further comprising a second electrode disposed on the first top surface of semiconductor structure. 
     
     
         3 . The light emitting device according to  claim 1 , wherein the connection metal layer comprises at least one of Ni, W, Ti, Pt, Au, an alloy of any combination thereof, or a stack of any combination thereof. 
     
     
         4 . The light emitting device according to  claim 1 , further comprising a light-extraction structure having irregularities on the first top surface of the semiconductor structure. 
     
     
         5 . The light emitting device according to  claim 1 , wherein the passivation layer comprises at least one of SiO 2 , epoxy-based photoresist, acrylic-based photoresist, SOG, or polyimide. 
     
     
         6 . The light emitting device according to  claim 1 , wherein the first electrode includes a reflective electrode. 
     
     
         7 . The light emitting device according to  claim 6 , the reflective electrode comprises W, Ti, Pt, Ag, Ni, or an alloy of any combination thereof. 
     
     
         8 . The light emitting device according to  claim 6 , wherein a thickness of the reflective electrode is in a range of about 10 nm to 500 nm. 
     
     
         9 . The light emitting device according to  claim 1 , wherein a width of the first electrode in a width direction is smaller than a width of the semiconductor structure. 
     
     
         10 . The light emitting device according to  claim 1 , wherein the first electrode comprises a plurality of layers. 
     
     
         11 . A light emitting device, comprising:
 a supporting layer;   a connection metal layer disposed on the supporting layer, the connection metal layer including a first portion, a second portion and a third portion;   a semiconductor structure disposed on the connection metal layer, the semiconductor including:
 a first semiconductor layer, 
 a second semiconductor layer, 
 an active layer disposed between the first semiconductor layer and second semiconductor layer, 
 a bottom surface facing the supporting layer, 
 a bottom surface facing the supporting layer, 
 a top surface opposite to the bottom surface, and 
 a side surface between the top surface and the bottom surface, 
 wherein the top surface includes an uneven portion having an irregular pattern and an edge portion having a flat surface, and 
 wherein the side surface is inclined relative to the bottom surface, and the edge portion surrounds the uneven portion and contacts the side surface; 
   a first electrode disposed between the semiconductor structure and the first portion of the connection metal layer, wherein a width of the first electrode in a width direction is smaller than a width of the bottom surface of the semiconductor structure; and   a passivation layer surrounding the semiconductor structure, the passivation layer contacts the connection metal layer in an area extending beyond the semiconductor structure,   wherein the second portion of the connection metal layer is disposed between the supporting layer and the bottom surface of the semiconductor structure,   wherein the third portion of the connection metal layer is disposed on the supporting layer and extends beyond the semiconductor structure, and   wherein the uneven portion and the edge portion of the top surface of the semiconductor structure meet at a location over the connection metal layer that does not overlap with the first electrode.   
     
     
         12 . The light emitting device according to  claim 11 , wherein the connection metal layer comprises at least one of Ni, W, Ti, Pt, Au, an alloy of any combination thereof, or a stack of any combination thereof. 
     
     
         13 . The light emitting device according to  claim 12 , wherein the passivation layer contacts the W, the Ti or an alloy of any combination thereof in the connection metal layer. 
     
     
         14 . The light emitting device according to  claim 11 , wherein the connection metal layer includes a stepped portion disposed between the first and second portions of the connection metal layer. 
     
     
         15 . The light emitting device according to  claim 14 , wherein the stepped portion of the connection metal layer does not overlap with the flat surface of the edge portion. 
     
     
         16 . The light emitting device according to  claim 11 , wherein the second portion of the connection metal layer is spaced away from the second portion of the connection metal layer and overlaps the uneven portion of the top surface. 
     
     
         17 . The light emitting device according to  claim 11 , wherein the passivation layer contacts the third portion of the connection metal layer in the area extending beyond the semiconductor structure. 
     
     
         18 . The light emitting device according to  claim 11 , wherein the first electrode includes a reflective layer comprising at least one of Ag, Ni, or Ti. 
     
     
         19 . The light emitting device according to  claim 18 , wherein the location at which the uneven portion and the edge portion of the top surface of the semiconductor structure meet is spaced away from the reflective layer of the first electrode in a vertical direction perpendicular to the width direction of the semiconductor structure. 
     
     
         20 . The light emitting device according to  claim 19 , wherein the connection metal layer includes a stepped portion disposed between the first and second portions of the connection metal layer, and
 wherein the stepped portion is located between the location at which the uneven portion and the edge portion of the top surface of the semiconductor structure meet and the reflective layer.