Light emitting device including an electrode on a textured surface, light emitting device package and lighting system

• US 8,809,884 B2
• Filed: 10/21/2010
• Issued: 08/19/2014
• Est. Priority Date: 10/22/2009
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: Hwang, Sung Min, Song, Hyun Don
• Primary Examiner(s): MUNOZ, ANDRES F
• Application Number:
  US12/909,184
• Publication Number:
  US 20110095306A1
• Time in Patent Office: 1,398 Days
• Field of Search: None
• US Class Current: 257/98
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/38 with a particular shape

Abstract

Disclosed are a light emitting device, a light emitting device package and a lighting system. The light emitting device of the embodiment includes a light emitting structure including a first conductive semiconductor layer, a second conductive semiconductor layer and an active layer between the first and second conductive semiconductor layers; a second electrode under the second conductive semiconductor layer; a first texture over a first region of the first conductive semiconductor layer; an A-electrode over the first region of the first conductive semiconductor layer; and a B-electrode over a second region of the first conductive semiconductor layer, wherein the B-electrode includes a pad electrode connected to a wire.

Claims

1. A light emitting device comprising:

a light emitting structure including a first conductive semiconductor layer, a second conductive semiconductor layer and an active layer between the first and second conductive semiconductor layers;

a second electrode under the second conductive semiconductor layer;

a first texture with a predetermined roughness pattern over a first region of the first conductive semiconductor layer;

an A-electrode over the first region of the first conductive semiconductor layer, wherein the A-electrode is on the first texture; and

a B-electrode over a second region of the first conductive semiconductor layer,

wherein the B-electrode is or includes a pad electrode,

wherein the B-electrode is directly disposed on the second region of the first conductive semiconductor layer,

wherein the A-electrode and the B-electrode are disposed on a same surface of the first conductive semiconductor layer, wherein said same surface of the first conductive semiconductor layer includes an upper surface of the first conductive semiconductor layer, and wherein a bottom surface of the A-electrode is at substantially a same level as a bottom surface of the B-electrode,

wherein a width of the second region having a substantially flat surface is wider than a width of the B-electrode,

wherein the A-electrode surrounds the B-electrode, and

wherein the A-electrode is in contact with both ends of the B-electrode.

2. The light emitting device as claimed in claim 1, wherein the first texture formed on the first region of the first conductive semiconductor layer includes a periodic pattern or a non-periodic roughness.

3. A light emitting device package including the light emitting device of claim 1 and further comprising a package body and third and fourth electrode layers provided on the package body, the light emitting device electrically connected to the third and fourth electrodes.

4. The light emitting device as claimed in claim 1, wherein a contact surface area between the B-electrode and the second region of the first conductive semiconductor layer is smaller than a contact surface area between the A-electrode and the first region of the first conductive semiconductor layer.

5. The light emitting device as claimed in claim 1, wherein the first texture includes a plurality of protruding formations and wherein an area of the second region of the first conductive semiconductor layer on which the B-electrode is directly disposed has substantially no protruding formations.

6. The light emitting device as claimed in claim 1, wherein the A-electrode and the B-electrode are in direct contact with the upper surface of the first conductive semiconductor layer.

7. The light emitting device as claimed in claim 1, wherein a top surface of the A-electrode is at substantially a same level as a top surface of the B-electrode.

8. The light emitting device as claimed in claim 1, wherein both the A-electrode and the B-electrode contact a top surface of the first conductive semiconductor layer.

9. The light emitting device as claimed in claim 1, wherein the first texture is not overlapped with the B-electrode and

the first texture is spaced away from the B-electrode.

10. The light emitting device as claimed in claim 1, wherein the A-electrode comprises at least two A-electrodes, and

wherein the B-electrode is disposed at a substantially center portion between the at least two A-electrodes.

11. A light emitting device comprising:

a light emitting structure including a first conductive semiconductor layer, a second conductive semiconductor layer and an active layer between the first and second conductive semiconductor layers;

a first electrode over the first conductive semiconductor layer;

a second electrode over the first conductive semiconductor layer; and

a third electrode under the second conductive semiconductor layer;

wherein;

the first conductive semiconductor layer has a surface that includes a first region and a second region,

the surface of the first conducive semiconductor layer in the first region of the first conductive semiconductor layer has a texture with a predetermined roughness pattern,

the surface of the first conductive semiconductor layer in the second region of the first conductive semiconductor layer is substantially flat,

the first electrode is coupled to the texture of the first region of the first conductive semiconductor layer,

the second electrode is in direct contact with the substantially flat surface of the second region of the first conductive semiconductor layer,

the first electrode and the second electrode are disposed on a same surface of the first conductive semiconductor layer, the same surface of the first conductive semiconductor layer including an upper surface of the first conductive semiconductor layer,

wherein a bottom surface of the first electrode is at substantially a same level as a bottom surface of the second electrode,

wherein a width of the second region having the substantially flat surface is wider than a width of the second electrode,

wherein the first electrode surrounds the second electrode, and

wherein the first electrode is in contact with both ends of the second electrode.

12. The light emitting device as claimed in claim 11, wherein the first electrode and the second electrode correspond to different portions of a same electrode layer.

13. The light emitting device as claimed in claim 11, wherein the first electrode is in direct contact with the texture of the first region of the first conductive semiconductor layer.

14. The light emitting device as claimed in claim 13, wherein an area of contact between the first electrode and the first region of the surface of the first conductive semiconductor layer is greater than an area of contact between the second electrode and the second region of the surface of the first conductive semiconductor layer.

15. The light emitting device as claimed in claim 11, wherein the texture with said predetermined roughness pattern is integrally formed on the surface of the first region of the first conductive semiconductor layer.

16. The light emitting device as claimed in claim 11, wherein the second electrode is a pad electrode.

17. The light emitting device as claimed in claim 11, wherein the predetermined roughness pattern includes an irregular pattern of protruding formations.

18. The light emitting device as claimed in claim 11, wherein the predetermined roughness pattern includes a substantially regular pattern of protruding formations.

19. The light emitting device as claimed in claim 11, wherein the first electrode and the second electrode are in direct contact with an uppermost surface of the first conductive semiconductor layer.

20. The light emitting device as claimed in claim 11, wherein the first electrode and the second electrode are disposed in direct contact with the same surface of the first conductive semiconductor layer.

21. The light emitting device as claimed in claim 11, wherein a top surface of the first electrode is at substantially a same level as a top surface of the second electrode.

22. The light emitting device as claimed in claim 11, wherein the texture is not overlapped with the second electrode and

the texture is spaced away from the second electrode.

23. The light emitting device as claimed in claim 11, wherein the first electrode comprises at least two first electrodes, and

wherein the second electrode is disposed at a substantially center portion between the at least two first electrodes.