Light emitting diode having vertical topology and method of making the same

• US 8,624,288 B2
• Filed: 08/26/2011
• Issued: 01/07/2014
• Est. Priority Date: 06/23/2006
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Electronics, Inc. (LG Corporation), LG Innotek Company Limited (LG Corporation)
• Inventors: Jang, Jun Ho, Choi, Jae Wan, Bae, Duk Kyu, Cho, Hyun Kyong, Park, Jong Kook, Kim, Sun Jung, Lee, Jeong Soo
• Primary Examiner(s): Lee, Calvin
• Assistant Examiner(s): STOWE, SCOTT C
• Application Number:
  US13/219,356
• Publication Number:
  US 20120018700A1
• Time in Patent Office: 865 Days
• Field of Search: None
• US Class Current: 257/99
• CPC Class Codes: H01L 2933/0016 relating to electrodes
• CPC Class Codes: H01L 2933/0083 Periodic patterns for optical field-shaping in or on the semiconductor body or semiconductor body package, e.g. photonic bandgap structures
• CPC Class Codes: H01L 33/0075 comprising nitride compounds
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/04 with a quantum effect structure or superlattice, e.g. tunnel junction
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• 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 33/40 Materials therefor
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating

Abstract

An LED having vertical topology and a method of making the same is capable of improving a luminous efficiency and reliability, and is also capable of achieving mass productivity. The method includes forming a semiconductor layer on a substrate; forming a first electrode on the semiconductor layer; forming a supporting layer on the first electrode; generating an acoustic stress wave at the interface between the substrate and semiconductor layer, thereby separating the substrate from the semiconductor layer; and forming a second electrode on the semiconductor layer exposed by the separation of the substrate.

Claims

1. A light emitting device, comprising:

a supporting layer having a metal material;

a metal layer comprising a first layer on the supporting layer, a second layer on the first layer, and a third layer on the second layer;

a first electrode on the metal layer, the first electrode comprising a reflective material;

a semiconductor structure having nitride material on the first electrode layer, the semiconductor structure comprising an n-type layer, an active layer on the n-type layer, and a p-type layer on the active layer;

a passivation layer between the semiconductor structure and the metal layer; and

a second electrode on the n-type layer of the semiconductor structure,

wherein the passivation layer and the first electrode are in contact with at least a part of a top surface of the metal layer, and

the metal layer is disposed between the first electrode layer and the supporting layer, and between the passivation layer and the supporting layer,

wherein the semiconductor structure includes a light-extraction structure.

4. The device according to claim 1, wherein the connection metal layer comprises at least one of Cu, Au, Sn, In, Ag, an alloy of any combination thereof, and a stack of any combination thereof.

5. The device according to claim 1, wherein the first layer comprises Au.

6. The device according to claim 1, wherein the first layer comprises an Au layer or a Cu layer.

7. The device according to claim 1, wherein the diffusion barrier layer comprises at least one of Ni, W, Ti, and Pt.

8. The device according to claim 1, wherein the second layer comprises at least one of Ni, W, Ti, Pt, Au, Pd, Cu, Al, Cr, Ag, and an alloy of any combination thereof.

9. The device according to claim 1, wherein the second layer contacts the first electrode.

10. The device according to claim 1, wherein the passivation layer comprises at least one of SiO₂, SiN, epoxy-based photoresist, acrylic-based photoresist, SOG, and polyimide.

11. The device according to claim 1, wherein the reflective electrode comprises at least one of Ag or Al.

12. The device according to claim 1, wherein the thickness of the reflective electrode is in a range of about 10 to 500 nm.

13. The device according to claim 1, wherein the thickness of the reflective electrode is more than 500 nm.

14. The device according to claim 1, further comprising a light-extraction structure on at least a portion of the semiconductor structure.

15. The device according to claim 14, wherein the light-extraction structure comprises irregularities on a surface of the semiconductor structure.

16. The device according to claim 1, further comprising a current diffusion layer arranged between the second type layer and the first electrode.

17. The device according to claim 16, wherein the current diffusion layer comprises an InGaN layer or an InGaN/GaN superlattice layer.

18. The device according to claim 1, wherein the passivation layer comprises at least two layers, the passivation layer comprising:

a first passivation layer; and

a second passivation layer on the first passivation layer.

19. The device according to claim 18, wherein the first passivation layer comprises an inorganic layer and the second passivation layer comprises an organic layer.

2. A light emitting device, comprising:

a supporting layer;

a metal layer comprising a first layer on the supporting layer, a second layer on the first layer, and a third layer on the second layer;

a first electrode on the metal layer;

a semiconductor structure on the first electrode, the semiconductor structure comprising an n-type nitride semiconductor layer, an active layer on the n-type nitride semiconductor layer, and a p-type nitride semiconductor layer on the active layer;

a passivation layer between the p-type nitride semiconductor layer and the metal layer; and

a second electrode on the n-type nitride semiconductor layer,

wherein the first electrode comprises a reflective layer,

wherein the passivation layer is in contact with at least a part of a top surface of the metal layer and a part of a bottom surface of the semiconductor structure, and

the metal layer is disposed between the first electrode and the supporting layer, and between the passivation layer and the supporting layer,

wherein the semiconductor structure includes a light-extraction structure,

wherein at least one of a first layer, a second layer and/or the third layer of the metal layer includes an adhesive material.

3. A light emitting device, comprising:

a supporting layer;

a connection metal layer comprising a first layer on the supporting layer, a diffusion barrier layer on the first layer, and a second layer on the diffusion barrier layer, wherein the first layer comprising a bonding layer for attaching the supporting layer;

a first electrode on the connection metal layer, the first electrode comprising a reflective electrode;

a semiconductor structure on the first electrode, the semiconductor structure comprising a first-type layer, an active layer on the first-type layer, and an second-type layer on the active layer;

a second electrode on the semiconductor structure; and

a passivation layer on a lateral surface of the semiconductor structure;

wherein a bottom surface of the passivation layer and the first electrode are in contact with a top surface of the connection metal layer, and

wherein the connection metal layer is disposed between the first electrode and the supporting layer, and between the passivation layer and the supporting layer.