Light emitting device and method of manufacturing the same

• US 8,912,556 B2
• Filed: 01/06/2014
• Issued: 12/16/2014
• Est. Priority Date: 03/07/2006
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Electronics, Inc. (LG Corporation), LG Innotek Company Limited (LG Corporation)
• Inventors: Kim, Jong Wook, Cho, Hyun Kyong, Yi, Gyu Chul, An, Sung Jin, Yoo, Jin Kyoung, Hong, Young Joon
• Primary Examiner(s): POTTER, ROY KARL
• Application Number:
  US14/147,947
• Publication Number:
  US 20140117378A1
• Time in Patent Office: 344 Days
• Field of Search: 257/86, 257/94, 257/99, 257/98, 257/103, 257/E21.002, 257/E33.066, 257/E23.074, 257/76
• US Class Current: 257/94
• CPC Class Codes: H01L 21/0237 Materials
• CPC Class Codes: H01L 21/0242 Crystalline insulating materials
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/36 characterised by the electrodes
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

A light emitting device and a method of manufacturing the same are disclosed. The light emitting device includes a buffer layer formed on a substrate, a nitride semiconductor layer including a first semiconductor layer, an active layer, and a second semiconductor layer, which are sequentially stacked on the buffer layer, a portion of the first semiconductor layer being exposed to the outside by performing mesa etching from the second semiconductor layer to the portion of the first semiconductor layer, and at least one nanocone formed on the second semiconductor layer.

Claims

1. A light emitting device, comprising:

a conductive substrate;

a nitride semiconductor layer formed on the conductive substrate, the nitride semiconductor layer including a second semiconductor layer on the conductive substrate, an active layer on the second semiconductor layer, and a first semiconductor layer on the active layer;

a light extraction structure formed on the first semiconductor layer, wherein a portion of the first semiconductor layer is free of the light extraction structure; and

a first electrode located on the portion of the first semiconductor layer that is free of the light extraction structure,

wherein a top of the light extraction structure is higher than a middle between a top surface of the first electrode and a bottom surface of the first electrode, on a top surface of the first semiconductor layer.

2. The light emitting device of claim 1, wherein the first electrode directly contacts with the first semiconductor layer.

3. The light emitting device of claim 1, wherein the active layer includes InGaN, and at least one of the first semiconductor layer or the second semiconductor layer includes AlGaN.

4. The light emitting device of claim 1, wherein the light extraction structure includes a plurality of cones.

5. The light emitting device according to claim 4, wherein at least one of the cones is formed with a shape of a pyramid.

6. The light emitting device of claim 4, wherein at least one of the cones is a nano scale cone.

7. The light emitting device of claim 6, wherein the nano scale cone has a size of 10 nm to 1000 nm.

8. The light emitting device of claim 4, wherein the first electrode is not overlapped with the cones.

9. The light emitting device of claim 1, wherein the conductive substrate includes Cu.

10. The light emitting device of claim 1, wherein the conductive substrate includes an ohmic layer disposed on a conductive support layer.

11. The light emitting device of claim 10, wherein the conductive support layer includes a soft metal and a hard metal.

12. The light emitting device of claim 10, wherein the ohmic layer includes a metal.

13. The light emitting device of claim 12, wherein the metal includes Ni.

14. The light emitting device of claim 10, wherein the ohmic layer has a specific contact resistance of 10⁻

3 to 10<sup>−

4</sup> Ω

cm².

15. A light emitting device, comprising:

a conductive substrate;

a nitride semiconductor layer formed on the conductive substrate, the nitride semiconductor layer including a second semiconductor layer on the conductive substrate, an active layer on the second semiconductor layer, and a first semiconductor layer on the active layer;

a light extraction structure formed on a first portion of first semiconductor layer; and

a first electrode located on a second portion of the first semiconductor layer,

wherein a top of the light extraction structure is higher than a middle between a top surface of the first electrode and a bottom surface of the first electrode, on a top surface of the first semiconductor layer.

16. The light emitting device of claim 15, wherein the first portion is not overlapped with the second portion.

17. The light emitting device of claim 15, wherein the first electrode directly contacts with the first semiconductor layer.

18. The light emitting device of claim 15, wherein the active layer includes InGaN, and at least one of the first semiconductor layer or the second semiconductor layer includes AlGaN.

19. The light emitting device of claim 16, wherein the conductive substrate includes an ohmic layer disposed on a conductive support layer, the ohmic layer includes a metal and the conductive substrate includes a soft metal and a hard metal.

20. The light emitting device of claim 19, wherein the metal of the ohmic layer includes Ni, and the conductive substrate includes Cu.