Nitride-based semiconductor light emitting device and method of manufacturing the same

• US 20070187698A1
• Filed: 09/22/2006
• Published: 08/16/2007
• Est. Priority Date: 02/10/2006
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd., Seoul National University Industry Foundation (Seoul National University)
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group), Seoul National University Industry Foundation (Seoul National University)
• Inventors: Lee, Jeong-wook, Jeon, Heon-su, Yoon, Suk-ho, Kim, Joo-sung
• Granted Patent: US 7,888,694 B2
• Time in Patent Office: Days
• US Class Current: 257/79
• CPC Class Codes: H01L 2933/0083 Periodic patterns for optical field-shaping in or on the semiconductor body or semiconductor body package, e.g. photonic bandgap structures
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

A nitride-based semiconductor light emitting device having an improved structure in which light extraction efficiency is improved and a method of manufacturing the same are provided. The nitride-based semiconductor light emitting device comprises an n-clad layer, an active layer, and a p-clad layer, which are sequentially stacked on a substrate, wherein the n-clad layer comprises a first clad layer, a second clad layer, and a light extraction layer interposed between the first clad layer and the second clad layer and composed of an array of a plurality of nano-posts, the light extraction layer diffracting or/and scattering light generated in the active layer.

Claims

1. A nitride-based semiconductor light emitting device comprising an n-clad layer, an active layer, and a p-clad layer, which are sequentially stacked on a substrate, wherein the n-clad layer comprises a first clad layer, a second clad layer, and a light extraction layer interposed between the first clad layer and the second clad layer and composed of an array of a plurality of nano-posts, the light extraction layer diffracting or/and scattering light generated in the active layer.

2. The nitride-based semiconductor light emitting device of claim 1, wherein the nano-posts are formed of a material having a different refraction index from a material used in forming the first clad layer and the second clad layer.

3. The nitride-based semiconductor light emitting device of claim 2, wherein the nano-posts are formed of a light transmission material having a refraction index of approximately 2.5 or less.

4. The nitride-based semiconductor light emitting device of claim 3, wherein the nano-posts are formed of a transparent material with respect to a wavelength in a range of approximately 200-780 nm.

5. The nitride-based semiconductor light emitting device of claim 2, wherein the nano-posts are formed of a material selected from the group consisting of SiO₂, SiN_x, Al₂O₃, HfO, TiO₂, ZrO, and ZnO or by adding a material selected from the group consisting of Mg, Ag, Zn, Sc, Hf, Zr, Te, Se, Ta, W, Nb, Cu, Si, Ni, Co, Mo, Cr, Mn, Hg, Pr, and La to an indium oxide.

6. The nitride-based semiconductor light emitting device of claim 1, wherein an arrangement period of the nano-posts is approximately 100-2000 nm.

7. The nitride-based semiconductor light emitting device of claim 6, wherein an arrangement period of the nano-posts is approximately 700 nm.

8. The nitride-based semiconductor light emitting device of claim 1, wherein a height of each of the nano-posts is approximately 100-1000 nm.

9. The nitride-based semiconductor light emitting device of claim 8, wherein a height of each of the nano-posts is approximately 300 nm.

10. The nitride-based semiconductor light emitting device of claim 1, wherein a diameter of each of the nano-posts is approximately 100-1000 nm.

11. The nitride-based semiconductor light emitting device of claim 1, wherein the first clad layer and the second clad layer are formed of an AlInGaN-based III-V-group nitride semiconductor material.

12. The nitride-based semiconductor light emitting device of claim 11, wherein the first clad layer and the second clad layer are formed of substantially the same material.

13. A method of manufacturing a nitride-based semiconductor light emitting device, the method comprising sequentially forming an n-clad layer, an active layer, and a p-clad layer on a substrate, wherein the forming of the n-clad layer comprises:

forming a first clad layer on the substrate;

forming a light transmission material layer on the first clad layer;

patterning the light transmission material layer to form a light extraction layer composed of an array of a plurality of nano-posts and diffracting or/and scattering light generated in the active layer; and

forming a second clad layer for embedding the light extraction layer on the first clad layer.

14. The method of claim 13, wherein the patterning of the light transmission material layer is performed using a hologram lithography method.

15. The method of claim 13, wherein the light transmission material layer is formed of a material having a different refraction index from a material used in forming the first clad layer and the second clad layer.

16. The method of claim 15, wherein the light transmission material layer is formed of a light transmission material having a refraction index of approximately 2.5 or less.

17. The method of claim 16, wherein the light transmission material layer is formed of a transparent material with respect to a wavelength in a range of approximately 200-780 nm.

18. The method of claim 15, wherein the light transmission material layer is formed of a material selected from the group consisting of SiO₂, SiN_x, Al₂O₃, HfO, TiO₂, ZrO, and ZnO or by adding a material selected from the group consisting of Mg, Ag, Zn, Sc, Hf, Zr, Te, Se, Ta, W, Nb, Cu, Si, Ni, Co, Mo, Cr, Mn, Hg, Pr, and La to an indium oxide.

19. The method of claim 13, wherein an arrangement period of the nano-posts is approximately 100-2000 nm.

20. The method of claim 19, wherein an arrangement period of the nano-posts is approximately 700 nm.

21. The method of claim 13, wherein a height of each of the nano-posts is approximately 100-1000 nm.

22. The method of claim 21, wherein a height of each of the nano-posts is approximately 300 nm.

23. The method of claim 13, wherein a diameter of each of the nano-posts is approximately 100-1000 nm.

24. The method of claim 13, wherein the first clad layer and the second clad layer are formed of an AlInGaN-based III-V-group nitride semiconductor material.

25. The method of claim 24, wherein the first clad layer and the second clad layer are formed of substantially the same material.

26. A nitride-based semiconductor light emitting device manufactured by the method of claim 13.