Light emitting diode

• US 20070267644A1
• Filed: 05/18/2007
• Published: 11/22/2007
• Est. Priority Date: 06/16/2005
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Electronics, Inc. (LG Corporation), LG Innotek Company Limited (LG Corporation)
• Inventors: Leem, See
• Granted Patent: US 8,008,646 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers

Abstract

A light emitting diode is disclosed, wherein the light extraction efficiency of a device can be enhanced by forming patterns on a substrate, a light emitting structure is formed on the substrate formed with the patterns, the substrate is removed from the light emitting structure, and patterns corresponding to those formed on the substrate are formed on the light emitting structure.

Claims

1. A light emitting diode comprising:

a first layer formed with patterns on a bottom surface thereof and having a first polarity;

an active layer formed on the first layer;

a second layer formed on the active layer and having an opposite polarity from the first polarity;

a first electrode formed on the second layer; and

a second electrode formed on the bottom surface of the first layer and formed perpendicularly to the first electrode.

2. The light emitting diode as defined in claim 1, further comprising a support formed on the first electrode.

3. The light emitting diode as defined in claim 2, wherein the support is formed with an ohmic contact material at least either on or underneath a conductive substrate.

4. The light emitting diode as defined in claim 2, further comprising a UBM (Under Bump Metallization) layer on the first electrode, and wherein the support is bonded to the UBM layer via solder.

7. The light emitting diode as defined in claim 1, wherein the first layer is a n-GaN layer and the second layer is a p-GaN layer.

8. The light emitting layer as defined in claim 3, wherein the conductive substrate comprises one or more of a group of Si, AlN, SiC, GaAs, Cu, W and Mo.

9. The light emitting diode as defined in claim 1, wherein each height of the pattern is in the range of 0.001˜

100 μ

m.

10. The light emitting diode as defined in claim 1, wherein the patterns comprise, on the bottom surface of the first layer, any one of a plurality of protruding striped shapes, a plurality of depressed striped shapes, and a plurality of depressed scratched shapes, or any one of a plurality of rectangular pillars, domes and rods having any one shape of depression and protrusion, and a combination of the depression and the protrusion.

11. The light emitting diode as defined in claim 1, wherein the un-GaN layer is formed near a margin of the first layer having the first polarity.

5. The light emitting diode as defined in claime 1, further comprising a reflection layer on the first electrode.

6. The light emitting diode as defined in claim 5, wherein the reflection layer comprises at least one or a combination of Ag, Al, Pt, Au, Ni, Ti, and a transmissive conductive oxide layer.

12. A light emitting diode comprising:

a first layer formed with patterns on a bottom surface thereof and having a first polarity;

an active layer formed on the first layer;

a second layer formed on the active layer and having an opposite polarity from the first polarity;

a first electrode formed on the second layer;

a conductive holder formed on the first electrode; and

a second electrode formed on a bottom surface of the first layer.

13. The light emitting diode as defined in claim 12, wherein the conductive holder is formed by any one or more methods of electro-plating method, electroless plating method, a CVD method and a sputtering method.

14. The light emitting diode as defined in claim 12, wherein the material of the conductive holder comprises at least one or more of a group of Cu, W, Au, Ni, Mo, Pt, Pd, Co, Ag, Al and Ti.

15. The light emitting diode as defined in claim 12, wherein each height of the pattern is in the range of 0.001˜

100 μ

m.

16. The light emitting diode as defined in claim 12, wherein the patterns comprise, on the bottom surface of the first layer, any one of a plurality of protruding striped shapes, a plurality of depressed striped shapes, and a plurality of depressed scratched shapes, or any one of a plurality of rectangular pillars, domes and rods having any one shape of depression and protrusion, and a combination of the depression and the protrusion.

17. A light emitting diode comprising:

a n-GaN based layer formed at a bottom surface thereof with patterns;

an active layer formed on the n-GaN based layer;

a p-GaN based layer formed on the active layer;

a first electrode formed on the p-GaN based layer; and

a second electrode formed on the bottom surface of the n-GaN based layer and formed perpendicularly to the first electrode.

18. The light emitting diode as defined in claim 17, wherein the second electrode is formed on the bottom surface of the n-GaN based layer formed with patterns.

19. The light emitting diode as defined in claim 17, wherein the second electrode is formed on a bottom surface of the n-GaN based layer not formed with the patterns.

20. A light emitting diode comprising:

a first layer formed with patterns on a bottom surface thereof and having a first polarity;

an active layer formed on the first layer;

a second layer formed on the active layer and having an opposite polarity from the first polarity;

a first electrode formed on the second layer; and

a second electrode formed on the bottom surface of the first layer; and

a reflection layer formed on the first electrode.

21. The light emitting diode as defined in claim 20, wherein the reflection layer comprises one or a combination of Ag, Al, Pt, Au, Ni, Ti, and a transmissive conductive oxide layer.