HIGH EFFICIENCY LIGHT EMITTING DIODE AND METHOD OF FABRICATING THE SAME

• US 20120119243A1
• Filed: 05/17/2011
• Published: 05/17/2012
• Est. Priority Date: 05/18/2010
• Status: Active Grant

• Current Assignee: Seoul Viosys Co., Ltd. (Seoul Semiconductor Co., Ltd.)
• Original Assignee: Seoul Optodevice Company Limited (Seoul Semiconductor Co., Ltd.)
• Inventors: LEE, Joon Hee, YOU, Jong Kyun, KIM, Chang Yeon, KIM, Da Hye, LIM, Hong Chul
• Granted Patent: US 9,029,888 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 2224/48463 the connecting portion on the bonding area of the semiconductor or solid-state body being a ball bond
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• 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 33/32 containing nitrogen
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/382 the electrode extending partially in or entirely through the semiconductor body
• CPC Class Codes: H01L 33/40 Materials therefor
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector

Abstract

Exemplary embodiments of the present invention relate to a high-efficiency light emitting diode (LED). The LED according to an exemplary embodiment includes a substrate, a semiconductor stack arranged on the substrate, wherein the semiconductor stack has a p-type semiconductor layer, an active layer and an n-type semiconductor layer, a first metal layer interposed between the substrate and the semiconductor stack, the first metal layer ohmic-contacted with the semiconductor stack, a first electrode pad arranged on the semiconductor stack, an electrode extension extending from the first electrode pad, wherein the electrode extension has a contact region contacting the n-type semiconductor layer, a first insulating layer interposed between the substrate and the semiconductor stack, wherein the first insulating layer covers a surface region of the p-type semiconductor layer under the contact region of the electrode extension, and a second insulating layer interposed between the first electrode pad and the semiconductor stack.

Claims

1. A light emitting diode (LED), comprising:

a substrate;

a semiconductor stack arranged on the substrate, the semiconductor stack comprising;

a p-type semiconductor layer;

an active layer; and

an n-type semiconductor layer;

a first metal layer interposed between the substrate and the semiconductor stack, the first metal layer ohmic-contacted with the semiconductor stack;

a first electrode pad arranged on the semiconductor stack;

an electrode extension extending from the first electrode pad, the electrode extension comprising a contact region being in contact with the n-type semiconductor layer;

a first insulating layer interposed between the substrate and the semiconductor stack, the first insulating layer covering a first region of the p-type semiconductor layer under the contact region of the electrode extension; and

is a second insulating layer interposed between the first electrode pad and the semiconductor stack.

2. The LED of claim 1, further comprising a second metal layer,

wherein the first metal layer comprises a groove exposing the semiconductor stack,

wherein the first insulating layer is interposed between the first metal layer and the substrate, covers the first metal layer and fills the groove, and comprises openings exposing the first metal layer, and

wherein the second metal layer is interposed between the substrate and the first insulating layer, and covers the first metal layer exposed through the openings of the first insulating layer.

3. The LED of claim 2, wherein the first electrode pad and the electrode extension are arranged above a region of the groove.

4. The LED of claim 2, wherein the first metal layer comprises a plurality of plates, the first insulating layer covers side surfaces and edges of the plurality of plates, and the plurality of plates are exposed by the openings of the first insulating layer, respectively.

5. The LED of claim 1, wherein the first insulating layer comprises at least one groove exposing the semiconductor stack, wherein the first metal layer is interposed between the first insulating layer and the substrate, and is ohmic-contacted with the semiconductor stack by filling the at least one groove.

6. The LED of claim 5, wherein a sidewall of the at least one groove is inclined.

7. The LED of claim 6, further comprising a second metal layer interposed between the substrate and the first metal layer, the second metal layer surrounding the first metal layer by covering an edge of the first metal layer.

8. The LED of claim 5, wherein an edge of the first metal layer is interposed between the first insulating layer and the substrate, and positioned between an edge of the semiconductor stack and an edge of the substrate.

9. The LED of claim 5, wherein the first insulating layer comprises a first region comprising a plurality of grooves, and wherein the first electrode pad and the electrode extension are positioned above a second region of the first insulating layer not comprising the grooves.

10. The LED of claim 1, wherein the substrate comprises:

a second metal layer comprising at least one of W and Mo; and

third metal layers arranged on first and second surfaces of the second metal layer, respectively, the third metal layers comprising a higher thermal expansion coefficient than the second metal layer.

11. The LED of claim 10, wherein the third metal layers comprise Cu.

12. The LED of claim 10, further comprising adhesive layers interposed between the second metal layer and the third metal layers, respectively.

13. The LED of claim 12, wherein the adhesive layers comprise at least one of Ni, Ti, Cr, and Pt.

14. The LED of claim 10, further comprising:

a first metal interposed between the substrate and the semiconductor stack; and

a second metal formed on a surface of the third metal layer opposite to the surface of the third metal layer arranged on the second surface of the second metal layer, the second metal to be symmetrical to the first metal.

15. The LED of claim 1, wherein the semiconductor stack comprises a roughened surface, and wherein the second insulating layer covers the roughened surface and comprises an uneven surface along the roughened surface.

16. The LED of claim 15, wherein the semiconductor stack comprises a flat surface on which the first electrode pad and the electrode extension are arranged.

17. The LED of claim 16, wherein the electrode extension contacts the flat surface.

18. The LED of claim 15, wherein the roughened surface is arranged under the electrode extension.

19. The LED of claim 1, comprising:

a plurality of first electrode pads; and

a plurality of electrode extensions extending from the plurality of first electrode pads, respectively.

20. The LED of claim 1, wherein the first region of the p-type semiconductor layer is arranged directly under the contact region of the electrode extension.