Semiconductor light emitting device with improved current spreading structure
View Patent ↗The invention relates to a high-quality semiconductor light emitting device which suppresses current concentration. The semiconductor light emitting device includes an n-type semiconductor layer, an active layer and a p-type semiconductor layer sequentially formed on a substrate. The semiconductor light emitting device further includes a p-electrode formed on the p-type semiconductor layer and an n-electrode formed on a surface of a mesa-etched portion of the n-type semiconductor layer. A trench is formed in the n-type semiconductor layer to prevent current concentration. The trench is extended from an upper surface of the mesa-etched portion of the n-type semiconductor layer or from a bottom surface of the substrate into the n-type semiconductor layer at a predetermined depth.
1. A semiconductor light emitting device comprising:
an n-type semiconductor layer, an active layer and a p-type semiconductor layer sequentially formed on a substrate;
a p-electrode formed on the p-type semiconductor layer; and
an n-electrode formed on an upper surface of a mesa-etched portion of the n-type semiconductor layer,
wherein the n-type semiconductor layer has a trench formed therein to prevent current concentration, and wherein the trench extends from a bottom surface of the substrate into the n-type semiconductor layer at a predetermined depth.
2. The semiconductor light emitting device according to claim 1 , wherein the trench is extended into the n-type semiconductor layer at a depth that is ½ or less of the thickness of the mesa-etched portion of the n-type semiconductor layer.
3. The semiconductor light emitting device according to claim 1 , wherein the trench is extended into the n-type semiconductor layer at a depth that is ⅙ to ½ of the thickness of the mesa-etched portion of the n-type semiconductor layer.
4. The semiconductor light emitting device according to claim 1 , wherein the trench is filled with an insulating material.
5. The semiconductor light emitting device according to claim 1 , wherein the trench is extended upward from a bottom surface of the substrate.
6. The semiconductor light emitting device according to claim 5 , wherein the trench is extended to the mesa-etched portion of the n-type semiconductor layer.
7. The semiconductor light emitting device according to claim 5 , wherein the trench is extended to the portion of the n-type semiconductor layer that is not mesa-etched.
8. The semiconductor light emitting device according to claim 5 , wherein the difference between the depth of the trench and the thickness of the substrate is ½ or less of the thickness of the mesa-etched portion of the n-type semiconductor layer.
9. The semiconductor light emitting device according to claim 5 , wherein the difference between the depth of the trench and the thickness of the substrate is ⅙ to ½ of the thickness of the mesa-etched portion of the n-type semiconductor layer.
10. The semiconductor light emitting device according to claim 1 , wherein the n-type semiconductor layer, the active layer and the p-type semiconductor layer are made of nitride semiconductor, and the substrate comprises a sapphire substrate.
11. A semiconductor light emitting device comprising:
an n-type semiconductor layer, an active layer and a p-type semiconductor layer sequentially formed on a substrate;
a p-electrode formed on the p-type semiconductor layer; and
an n-electrode formed on an upper surface of a mesa-etched portion of the n-type semiconductor layer,
wherein the n-type semiconductor layer has a trench formed therein to prevent current concentration, and wherein the trench extends from a bottom surface of the substrate into the n-type semiconductor layer at a predetermined depth, and the trench passes through only the substrate and the n-type semiconductor layer.