Light emitting device and method of manufacturing the same

• US 20110127554A1
• Filed: 05/27/2010
• Published: 06/02/2011
• Est. Priority Date: 12/02/2009
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Min, Bok-ki, Lee, Jae-won, Kim, Jun-youn, Tak, Young-jo, Jeong, Hyung-su
• Granted Patent: US 8,525,201 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 2933/0016 relating to electrodes
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• CPC Class Codes: H01L 33/382 the electrode extending partially in or entirely through the semiconductor body
• CPC Class Codes: H01L 33/387 with a plurality of electrode regions in direct contact with the semiconductor body and being electrically interconnected by another electrode layer
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

A light emitting device may include a substrate, an n-type clad layer, an active layer, and a p-type clad layer. A concave-convex pattern having a plurality of grooves and a mesa between each of the plurality of grooves may be formed on the substrate, and a reflective layer may be formed on the surfaces of the plurality of grooves or the mesa between each of the plurality of grooves. Therefore, light generated in the active layer may be reflected by the reflective layer, and extracted to an external location.

Claims

1. A light emitting device comprising:

a concave-convex pattern on a substrate, the concave-convex pattern including a plurality of grooves and a mesa between each of the plurality of grooves;

a first reflective layer on a side surface of each of the plurality of grooves;

an n-type clad layer on the concave-convex pattern;

an active layer on the n-type clad layer;

a p-type clad layer on the active layer;

a first electrode on a surface of the substrate; and

a second electrode on a surface of the p-type clad layer.

2. The light emitting device of claim 1, further comprising:

a buffer layer on a top surface of the mesa and the first reflective layer.

3. The light emitting device of claim 2, further comprising:

a space between a top portion of each of the plurality of grooves and the n-type clad layer.

4. The light emitting device of claim 1, further comprising:

a second reflective layer on a top surface of the mesa; and

a buffer layer on the second reflective layer and a bottom surface of each of the plurality of grooves.

5. The light emitting device of claim 1, wherein the n-type clad layer is grown by using Epitaxial Lateral Over Growth (ELOG).

6. The light emitting device of claim 1, wherein the first reflective layer includes a metal layer or a dielectric layer.

7. The light emitting device of claim 6, wherein the metal layer includes at least a material selected from the group consisting of silver (Ag), aluminium (Al), gold (Au), titanium (Ti), zirconium diboride (ZrB₂), zirconium nitride (ZrN), Hf_xZr_(l-z)B₂, titanium nitride (TiN), and chromium (Cr).

8. The light emitting device of claim 6, wherein the dielectric layer includes a Distributed Bragg Reflector (DBR) layer.

9. The light emitting device of claim 1, wherein a distance between each of the plurality of grooves is in the range of about 10 nm to about 100 μ

m, and a depth of each of the plurality of grooves is in the range of about 10 nm to about 100 μ

m.

10. The light emitting device of claim 1, wherein the side surface of each of the plurality of grooves includes an inclined surface.

11. The light emitting device of claim 1, wherein each of the plurality of grooves includes a V-shaped cross-section.

12. The light emitting device of claim 1, wherein the concave-convex pattern is formed on a dielectric layer separate from the substrate.

13. The light emitting device of claim 12, further comprising:

a second reflective layer on a top surface of the mesa; and

a buffer layer on the second reflective layer and a bottom surface of each of the plurality of grooves.

14. The light emitting device of claim 12, wherein the n-type clad layer is grown by using ELOG.

15. The light emitting device of claim 12, further comprising:

a space between the first reflective layer and the n-type clad layer.

16. A method of manufacturing a light emitting device, the method comprising:

depositing a mask layer on a substrate;

forming a concave-convex pattern on the substrate by using the mask layer, the concave-convex pattern including a plurality of grooves and a mesa between each of the plurality of grooves;

depositing a reflective layer on an inner surface of the plurality of grooves and a top surface of the mesa between each of the plurality of grooves;

partially exposing the substrate on at least one of a bottom surface of the inner surface of the plurality of grooves and the top surface of the mesa between each of the plurality of grooves;

growing an n-type clad layer on the exposed substrate;

forming an active layer on the n-type clad layer; and

forming a p-type clad layer on the active layer.

17. The method of claim 16, further comprising:

depositing a buffer layer on the exposed substrate and the n-type clad layer.

18. The method of claim 16, wherein the n-type clad layer is grown by using Epitaxial Lateral Over Growth (ELOG).

19. The method of claim 16, wherein the plurality of grooves are formed by anisotropic etching so as to include an inclined surface.

20. The method of claim 16, further comprising:

forming a space between the reflective layer and the n-type clad layer.

21. A method of manufacturing a light emitting device, the method comprising:

depositing a dielectric layer on a substrate;

forming a concave-convex pattern by etching the dielectric layer, the concave-convex pattern including a plurality of grooves and a mesa between each of the plurality of grooves;

depositing a reflective layer on an inner surface of the plurality of grooves and a top surface of the mesa between each of the plurality of grooves;

etching the substrate so as to partially expose the substrate on a bottom surface of the plurality of grooves;

growing an n-type clad layer on the exposed substrate;

forming an active layer on the n-type clad layer; and

forming a p-type clad layer on the active layer.

22. The method of claim 21, further comprising:

depositing a buffer layer on the exposed substrate and the n-type clad layer.

23. The method of claim 21, wherein the n-type clad layer is grown by using Epitaxial Lateral Over Growth (ELOG).

24. The method of claim 21, wherein the plurality of grooves are formed by anisotropic etching so as to include an inclined surface.