Light emitting device and method of fabricating the same
View Patent ↗Disclosed are a light emitting device and a method of fabricating the same. The light emitting device comprises a substrate. A plurality of light emitting cells are disposed on top of the substrate to be spaced apart from one another. Each of the light emitting cells comprises a first upper semiconductor layer, an active layer, and a second lower semiconductor layer. Reflective metal layers are positioned between the substrate and the light emitting cells. The reflective metal layers are prevented from being exposed to the outside.
1. A light emitting device, comprising:
a substrate;
a first electrode;
a first conductivity-type nitride semiconductor layer arranged on the substrate;
a second conductivity-type nitride semiconductor layer arranged on the first conductivity-type nitride semiconductor layer, a first surface of the second conductivity-type nitride semiconductor layer comprising a roughened surface;
an active layer disposed between the first conductivity-type nitride semiconductor layer and the second conductivity-type nitride semiconductor layer;
a reflective metal layer disposed between the first conductivity-type nitride semiconductor layer and the substrate, the reflective metal layer contacting a portion of the first conductivity-type nitride semiconductor layer;
a protective metal layer disposed between the reflective metal layer and the substrate, the protective metal layer covering a portion of the reflective metal layer;
a first insulating layer covering a portion of the first conductivity-type nitride semiconductor layer and a portion of the protective metal layer;
a first connection metal layer electrically connecting the protective metal layer and the first electrode;
a bonding metal layer disposed between substrate and the first conductivity-type nitride semiconductor layer,
wherein the first electrode is on the same side of the substrate as the roughened first surface of the second conductivity-type nitride semiconductor layer.
2. The light emitting device of claim 1 , wherein the first insulating layer contacts a second surface of the second conductivity-type nitride semiconductor layer, the second surface being opposite to the roughened first surface of the second conductivity-type nitride semiconductor layer.
3. The light emitting device of claim 2 , wherein the first insulating layer contacts a plurality of separated second surfaces of the second conductivity-type nitride semiconductor layer.
4. The light emitting device of claim 1 , further comprising a second connection metal layer connecting a plurality of second conductivity-type nitride semiconductor layers in parallel.
5. The light emitting device of claim 1 , wherein the first insulating layer covers a side surface of the active layer.
6. The light emitting device of claim 1 , wherein a portion of the first insulating layer is arranged on a part of the substrate that is not disposed directly under the active layer.
7. The light emitting device of claim 1 , wherein the first connection metal layer and the bonding metal layer fill out an area between the first conductivity-type nitride semiconductor layer and the substrate.
8. The light emitting device of claim 1 , further comprising a second insulating layer disposed between the first insulating layer and the bonding metal layer.
9. The light emitting device of claim 8 , wherein the protective metal layer is disposed between the first insulation layer and the second insulation layer.
10. The light emitting device of claim 8 , wherein a portion of the second insulating layer covers a portion of the first connection metal layer that is not disposed directly under the active layer.
11. The light emitting device of claim 1 , wherein the second conductivity-type nitride semiconductor layer comprises etched portions that are deeper than the roughened first surface.
12. The light emitting device of claim 1 , wherein the second conductivity-type nitride semiconductor layer comprises a first light-extraction structure comprising a first height and a second light-extraction structure comprising a second height.
13. The light emitting device of claim 12 , wherein the second height is greater than the first height.
14. The light emitting device of claim 12 , wherein the second light-extraction structure exposes the first insulating layer.
15. The light emitting device of claim 1 , further comprising a mesa-etched structure arranged on the substrate, wherein the mesa-etched structure is opposite to the roughened first surface of the second conductivity-type nitride semiconductor layer.
16. The light emitting device of claim 15 , wherein the mesa-etched structure is arranged on the first insulation layer.
17. The light emitting device of claim 15 , wherein the first insulation layer is arranged adjacent to a portion of the first conductivity-type nitride semiconductor layer that directly contacts the protective metal layer.
18. The light emitting device of claim 17 , wherein the first reflective metal layer is arranged adjacent to the portion of the first conductivity-type nitride semiconductor layer that directly contacts the protective metal layer.
19. The light emitting device of claim 18 , further comprising a second insulation layer, wherein a portion of the protective metal layer and the first insulation layer are arranged on the second insulation layer.
20. The light emitting device of claim 15 , further comprising a conductive layer, wherein the mesa etched structure is arranged on the conductive layer.