Semiconductor light emitting device
A semiconductor light emitting device and a method of manufacturing the semiconductor light emitting device are provided. The semiconductor light emitting device comprises a substrate having a top surface that is curved to protrude, and a light emitting structure that is curved to protrude on the substrate and comprises an active layer.
1. A semiconductor light emitting device comprising:
a substrate comprising a top surface having a curvature in a first direction and a bottom surface being flat, wherein the substrate has a peak point on the top surface and gradually becomes lower towards an edge of the top surface;
an un-doped layer curved in the first direction on the substrate;
a first conductive type semiconductor layer curved in the first direction on the un-doped layer;
an active layer curved in the first direction on the first conductive type semiconductor layer; and
a second conductive type semiconductor layer curved in the first direction on the active layer,
wherein each of the top surface of the substrate, the un-doped layer, the first conductive type semiconductor layer, the active layer and the second type semiconductor layer is curved towards the same direction.
2. The semiconductor light emitting device according to claim 1 , wherein the first conductive type semiconductor layer, the active layer, and the second conductive type semiconductor layer are curved to protrude upward.
3. The semiconductor light emitting device according to claim 1 , wherein the first conductive type semiconductor layer, the active layer, and the second conductive type semiconductor layer are curved to protrude downward.
4. The semiconductor light emitting device according to claim 1 , wherein the first conductive type semiconductor layer, the active layer, and the second conductive type semiconductor layer are curved with a same curvature.
5. The semiconductor light emitting device according to claim 1 , wherein at least one of the layers that are curved is provided with a protrusion/groove pattern.
6. The semiconductor light emitting device according to claim 1 , further comprising at least one of a semiconductor layer having the same conductive type as the first conductive type semiconductor layer, a transparent electrode layer, a reflective electrode layer, and a conductive substrate that are formed on the second conductive type semiconductor layer and curved to protrude in the first direction.
7. The semiconductor light emitting device according to claim 1 , wherein the substrate comprises at least one of sapphire (Al 2 O 3 ), SiC, Si, GaAs, GaN, ZnO, Si, GaP, InP, and Ge, and a highest point of the substrate is higher than a lowest point by 1-100 μm.
8. The semiconductor light emitting device according to claim 1 , wherein each of the first conductive type semiconductor layer, the active layer and the second conductive type semiconductor layer has substantially equal thickness in an entire area.
9. The semiconductor light emitting device according to claim 1 , wherein the first direction includes only one protrusion.
10. The semiconductor light emitting device according to claim 1 , further comprising at least one of a buffer layer and undoped semiconductor layer between the first conductive type semiconductor layer and the substrate.
11. The semiconductor light emitting device according to claim 1 , wherein the first conductive type semiconductor layer, the active layer and the second conductive type semiconductor layer are curved with a same curvature as the substrate.
12. The semiconductor light emitting device according to claim 1 , wherein the top surface of the substrate protrudes with a predetermined curvature from both opposite lowest points to a central highest point.
13. The semiconductor light emitting device according to claim 1 , wherein the lowest points of the top surface of the substrate are formed on at least two sides.
14. The semiconductor light emitting device according to claim 1 , wherein a thickness of the substrate at a highest point of the top surface is greater than a thickness of the substrate at a lowest point of the top surface by 1-100 μm.
15. The semiconductor light emitting device according to claim 1 , wherein the top surface of the substrate is curved with a protrusion/groove pattern.
16. The semiconductor light emitting device according to claim 15 , wherein the protrusion/groove pattern comprises at least one of a plurality of cone-shaped protrusions, a plurality of hemi-circular-shape protrusions, a plurality of convex lens-shaped protrusions, and a plurality of polygonal-shaped protrusions.