Semiconductor light emitting device having patterned substrate
View Patent ↗There is provided a semiconductor light emitting device having a patterned substrate and a manufacturing method of the same. The semiconductor light emitting device includes a substrate; a first conductivity type nitride semiconductor layer, an active layer and a second conductivity type nitride semiconductor layer sequentially formed on the substrate, wherein the substrate is provided on a surface thereof with a pattern having a plurality of convex portions, wherein out of the plurality of convex portions of the pattern, a distance between a first convex portion and an adjacent one of the convex portions is different from a distance between a second convex portion and an adjacent one of the convex portions.
1. A nitride semiconductor light emitting device having a patterned substrate, the nitride semiconductor light emitting device comprising:
a substrate;
a first conductivity type nitride semiconductor layer, an active layer and a second conductivity type nitride semiconductor layer sequentially formed on the substrate,
wherein the substrate is provided on a surface thereof with a pattern having a plurality of convex portions,
wherein out of the plurality of convex portions of the pattern, a distance between a first convex portion and an adjacent one of the convex portions is different from a distance between a second convex portion and an adjacent one of the convex portions,
wherein the first conductivity type nitride semiconductor layer has a locally protruded and depressed structure, and the active layer has three-dimensional geometric curved indentations corresponding to the locally protruded and depressed structure of the first conductive nitride semiconductor layer.
2. The nitride semiconductor light emitting device of claim 1 , wherein the convex portions of the pattern of the substrate are non-periodically arranged.
3. The nitride semiconductor light emitting device of claim 1 , wherein the convex portions of the pattern of the substrate each have a vertical cross-section formed of a hemisphere.
4. The nitride semiconductor light emitting device of claim 3 , wherein the first and second convex portions have bottom surfaces sized differently from each other.
5. The nitride semiconductor light emitting device of claim 1 , wherein the convex portions of the pattern of the substrate each have a vertical cross-section formed of a polygon.
6. The nitride semiconductor light emitting device of claim 5 , wherein the first and second convex portions are shaped identically and have bottom surfaces sized differently from each other.
7. The nitride semiconductor light emitting device of claim 5 , wherein the first and second convex portions differ in a growth plane of a nitride semiconductor from each other.
8. The nitride semiconductor light emitting device of claim 1 , wherein the convex portions of the pattern of the substrate have vertical cross-sections formed of a combination of a hemisphere and a polygon.
9. The nitride semiconductor light emitting device of claim 5 , wherein the polygon comprises one of a trapezium, a square and a triangle.
10. The nitride semiconductor light emitting device of claim 8 , wherein the polygon comprises one of a trapezium, a square and a triangle.
11. The nitride semiconductor light emitting device of claim 1 , further comprising at least one buffer layer formed between the substrate and the first conductivity type nitride semiconductor layer.
12. The nitride semiconductor light emitting device of claim 1 , wherein the substrate is a sapphire substrate.
13. The nitride semiconductor light emitting device of claim 1 , wherein the convex portions each have a size of 0.1 μm to 10 μm.