High efficiency light emitting diode and method for fabricating the same

• US 8,791,483 B2
• Filed: 03/31/2011
• Issued: 07/29/2014
• Est. Priority Date: 03/31/2010
• Status: Active Grant

• Current Assignee: Seoul Viosys Co., Ltd. (Seoul Semiconductor Co., Ltd.)
• Original Assignee: Seoul Optodevice Company Limited (Seoul Semiconductor Co., Ltd.)
• Inventors: Ye, Kyung Hee, Kim, Chang Youn, Shin, Jin Cheol, Lee, Joon Hee, You, Jong Kyun, Lim, Hong Chol
• Primary Examiner(s): Li, Meiya
• Application Number:
  US13/077,254
• Publication Number:
  US 20110241050A1
• Time in Patent Office: 1,216 Days
• Field of Search: 257/79, 257/81, 257/94, 257 98-100, 257/103, 257/E33.005, 257/E33.067, 257/E33.001, 257/E33.062, 257/E21.211, 438/22, 438/25, 438/26, 438/29
• US Class Current: 257/98
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/24 of the light emitting region, e.g. non-planar junction
• 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 33/42 Transparent materials
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector

Abstract

A high-efficiency light emitting diode including: a semiconductor stack positioned on a support substrate, including a p-type compound semiconductor layer, an active layer, and an n-type compound semiconductor layer; an insulating layer disposed in an opening that divides the p-type compound semiconductor layer and active layer; a transparent electrode layer disposed on the insulating layer and the p-type compound semiconductor layer; a reflective insulating layer covering the transparent electrode layer, to reflect light from the active layer away from the support substrate; a p-electrode covering the reflective insulating layer; and an n-electrode is formed on top of the n-type compound semiconductor layer. The p-electrode is electrically connected to the transparent electrode layer through the insulating layer.

Claims

1. A light emitting diode (LED) comprising:

a support substrate;

a semiconductor stack disposed on the support substrate, the semiconductor stack comprising;

a first compound semiconductor layer having an upper surface and comprising first protrusions disposed on the upper surface;

a second compound semiconductor layer;

an active layer disposed between the first compound semiconductor layer and the second compound semiconductor layer; and

at least one opening that extends through the second compound semiconductor layer and the active layer, and exposes a portion of the first compound semiconductor layer, the portion facing the substrate;

an insulating layer disposed on the exposed portion of the first compound semiconductor layer and a sidewall of the at least one opening;

an electrode structure electrically connected to the second compound semiconductor layer and extending outside of the semiconductor stack; and

an electrode pad disposed the outside of the semiconductor stack and on the electrode structure.

2. The light-emitting diode of claim 1, wherein the electrode structure comprises:

an electrode layer disposed on the insulating layer and contacting the second compound semiconductor layer; and

a first electrode disposed on the electrode layer.

3. The light-emitting diode of claim 2, wherein the electrode layer comprises a metal or a conductive metal oxide.

4. The light-emitting diode of claim 2, wherein the electrode layer comprises at least one of Ni, Au, indium tin oxide (ITO), ZnO, Ag, Pt, Pd, and Rh.

5. The light-emitting diode of claim 2, further comprising a reflective layer disposed between the electrode layer and the first electrode.

6. The light-emitting diode of claim 5, wherein the reflective layer comprises at least one material selected from the group consisting of Al, Ag, Si, Ti, Ta, Nb, In, Sn, Si_xO_yN_z, Ti_xO_y, Ta_xO_y and Nb_xO_y.

7. The light-emitting diode of claim 5, wherein the reflective layer comprises through-holes, the first electrode extending through the through holes and contacting the second compound semiconductor layer.

8. The light-emitting diode of claim 1, further comprising second protrusions comprising a dielectric material, the second protrusions being disposed on the first protrusions.

9. The light-emitting diode of claim 8, wherein:

the first protrusions are generally pyramidal; and

the second protrusions are generally conical.

10. The light-emitting diode of claim 1, wherein the support substrate comprises at least one of Si, SiC, AlN, Si—

Al, and CuW.

11. The light-emitting diode of claim 1, wherein the semiconductor stack comprises a plurality of the at least one opening arranged in a matrix.

12. The light-emitting diode of claim 1, further comprising a second electrode disposed on the upper surface of the first compound semiconductor layer.

13. The light-emitting diode of claim 12, wherein the second electrode is disposed on a lower surface of the first compound semiconductor layer.

14. The light-emitting diode of claim 12, wherein the second electrode is disposed on a planar portion of the upper surface of the first compound semiconductor layer.

15. The light-emitting diode of claim 14, wherein the second electrode is disposed above the first protrusions.

16. The light-emitting diode of claim 5, wherein the reflective layer comprises a distributed Bragg reflector (DBR).

17. The light-emitting diode of claim 1, wherein the first compound semiconductor layer comprises an N-type impurity;

and

the second compound semiconductor layer comprises a P-type impurity.