Light-emitting diode device and method for manufacturing the same

1. A light-emitting diode device, comprising:

a substrate;

an epitaxial layered structure which includes a first-type semiconductor layer, an active layer, and a second-type semiconductor layer sequentially formed on said substrate in such order, and which is formed with an indentation extending through said second-type semiconductor layer and said active layer and terminating at said first-type semiconductor layer to expose a portion of the first-type semiconductor layer;

a current-spreading layer which is disposed on said epitaxial layered structure opposite to said substrate;

a current-blocking unit which is disposed on said current-spreading layer; and

a distributed Bragg reflector which covers said epitaxial layered structure, said current-spreading layer, and said current-blocking unit, and extends into said indentation of said epitaxial layered structure,

wherein

one of said current-spreading layer, said current-blocking unit, and a combination thereof has a patterned rough structure,

wherein said current-blocking unit includes a second current-blocking layer which is formed on said current-spreading layer opposite to said epitaxial layered structure.

2. The light-emitting diode device according to claim 1 , wherein said patterned rough structure has a plurality of protrusions that protrude in a direction away from said epitaxial layered structure.

3. The light-emitting diode device according to claim 2 , wherein each of said protrusions is one of a hemispherical protrusion, a conical protrusion, and a frustoconical protrusion.

4. The light-emitting diode device according to claim 3 , wherein a projection of each of said protrusions on said epitaxial layered structure has a diameter of not greater than 50 μm.

5. The light-emitting diode device according to claim 2 , wherein each of said protrusions has a height of not less than 100 nm.

6. The light-emitting diode device according to claim 2 , wherein a distance between two adjacent ones of said protrusions is not greater than 20 μm.

7. The light-emitting diode device according to claim 1 , wherein said distributed Bragg reflector has a thickness of not less than 3 μm.

8. The light-emitting diode according to claim 1 , wherein said current-blocking unit further includes a first current-blocking layer formed on said epitaxial layered structure opposite to said substrate, and said current-spreading layer is disposed over said first current-blocking layer and is connected to said epitaxial layered structure.

9. The light-emitting diode according to claim 1 , wherein said distributed Bragg reflector is formed with a first through hole and a second through hole, and said light-emitting diode further comprises a P-type electrode unit and an N-type electrode, said P-type electrode unit being formed in said first through hole and being electrically connected to said current-spreading layer, and said N-type electrode being formed in said second through hole and being electrically connected to said first-type semiconductor layer of said epitaxial layered structure.

10. A method for manufacturing a light-emitting diode device, comprising the steps of:

a) forming an epitaxial layered structure on a substrate, the epitaxial layered structure including a first-type semiconductor layer, an active layer, and a second-type semiconductor layer that are sequentially stacked on the substrate in such order;

b) etching the epitaxial layered structure to form an indentation which extends through the second-type semiconductor layer and the active layer, and which terminates at the first-type semiconductor layer to expose a portion of the first-type semiconductor layer;

c) forming a current-blocking unit and a current-spreading layer on the epitaxial layered structure opposite to the substrate, one of the current-spreading layer, the current-blocking unit, and a combination thereof being formed with a patterned rough structure;

d) covering the epitaxial layered structure, the current-spreading layer, and the current-blocking unit with a distributed Bragg reflector which extends into the indentation of the epitaxial layered structure;

e) forming a first through hole and a second through hole in the distributed Bragg reflector; and

f) forming a P-type electrode unit in the first through hole and an N-type electrode in the second through hole, the P-type electrode unit being electrically connected to the current-spreading layer, and the N-type electrode being electrically connected to the first-type semiconductor layer of the epitaxial layered structure.

11. The method according to claim 10 , wherein the patterned rough structure has a plurality of protrusions that protrude in a direction away from the epitaxial layered structure.

12. The method according to claim 10 , wherein each of the protrusions is one of a hemispherical protrusion, a conical protrusion, and a frustoconical protrusion.

13. The method according to claim 12 , wherein a projection of each of the protrusions on the epitaxial layered structure has a diameter of not greater than 50 μm.

14. The method according to claim 10 , wherein each of the protrusions has a height of not less than 100 nm.

15. The method according to claim 10 , wherein a distance between two adjacent ones of the protrusions is not greater than 20 μm.

16. The method according to claim 10 , wherein in step e), the distributed Bragg reflector has a thickness of not less than 3 μm.

17. The method according to claim 10 , wherein in step c), the current-blocking unit includes a first current-blocking layer formed on the epitaxial layered structure opposite to the substrate, and the current-spreading layer is disposed over the first current-blocking layer and is connected to the epitaxial layered structure.

18. A method for manufacturing a light-emitting diode device, comprising the steps of:

a) forming an epitaxial layered structure on a substrate, the epitaxial layered structure including a first-type semiconductor layer, an active layer, and a second-type semiconductor layer that are sequentially stacked on the substrate in such order;

b) etching the epitaxial layered structure to form an indentation which extends through the second-type semiconductor layer and the active layer, and which terminates at the first-type semiconductor layer to expose a portion of the first-type semiconductor layer;

c) forming a current-blocking unit and a current-spreading layer on the epitaxial layered structure opposite to the substrate, wherein one of the current-spreading layer, the current-blocking unit, and a combination thereof is formed with a patterned rough structure, and

the current-blocking unit includes a second current-blocking layer which is formed on the current-spreading layer opposite to the epitaxial layered structure; and

d) covering the epitaxial layered structure, the current-spreading layer, and the current-blocking unit with a distributed Bragg reflector which extends into the indentation of the epitaxial layered structure.

19. The method according to claim 18 , wherein the patterned rough structure has a plurality of protrusions that protrude in a direction away from the epitaxial layered structure.

20. The method according to claim 18 , wherein a distance between two adjacent ones of the protrusions is not greater than 20 μm.