GaN compound semiconductor light emitting element and method of manufacturing the same

• US 8,143,640 B2
• Filed: 07/28/2011
• Issued: 03/27/2012
• Est. Priority Date: 10/22/2004
• Status: Active Grant

• Current Assignee: Seoul Viosys Co., Ltd. (Seoul Semiconductor Co., Ltd.)
• Original Assignee: Postech Foundation, Seoul Optodevice Company Limited (Seoul Semiconductor Co., Ltd.)
• Inventors: Lee, Jong Lam
• Primary Examiner(s): Nguyen, Thinh T
• Application Number:
  US13/192,848
• Publication Number:
  US 20110278628A1
• Time in Patent Office: 243 Days
• Field of Search: 257/98, 257/99, 257/100, 257/94, 257/95, 257/77, 257/183, 257/E31.001, 257/103, 438/27, 438/29
• US Class Current: 257/98
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/32 containing nitrogen
• 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 33/40 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

The present invention relates to a gallium nitride (GaN) compound semiconductor light emitting element (LED) and a method of manufacturing the same. The present invention provides a vertical GaN LED capable of improving the characteristics of a horizontal LED by means of a metallic protective film layer and a metallic support layer. According to the present invention, a thick metallic protective film layer with a thickness of at least 10 microns is formed on the lateral and/or bottom sides of the vertical GaN LED to protect the element against external impact and to easily separate the chip. Further, a metallic substrate is used instead of a sapphire substrate to efficiently release the generated heat to the outside when the element is operated, so that the LED can be suitable for a high-power application and an element having improved optical output characteristics can also be manufactured. A metallic support layer is formed to protect the element from being distorted or damaged due to impact. Furthermore, a P-type electrode is partially formed on a P-GaN layer in a mesh form to thereby maximize the emission of photons generated in the active layer toward the N-GaN layer.

Claims

1. A light emitting element, comprising:

a metallic support layer;

a reflective film electrode arranged on the metallic support layer;

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

an anti-reflective layer arranged on the nitride semiconductor structure;

an insulation layer, the nitride semiconductor structure being arranged on the insulation layer, and the insulation layer covering the side surface and extending beyond an edge of the nitride semiconductor structure; and

a metallic protective film layer, the reflective film electrode and the insulation layer being arranged on the metallic protective film layer.

2. The light emitting element of claim 1, wherein a portion of the insulation layer is disposed directly between the reflective film electrode and the nitride semiconductor structure.

3. The light emitting element of claim 1, wherein the reflective film electrode comprises a contact metallic layer comprising Ni, Pt, Ru, Ir, Rh, Ta, Ti, W, Pd, V, Co, Au, Re or any combination thereof, and a reflective metallic layer comprising Ag, Al, or a combination thereof.

4. The light emitting element of claim 3, wherein the thickness of the contact metallic layer is 5 Å

to 500 Å

.

5. The light emitting element of claim 3, wherein the thickness of reflective metallic layer is 100 Å

to 9000 Å

.

6. The light emitting element of claim 3, wherein the thickness of the reflective metallic layer is 1000 Å

to 2000 Å

.

7. The light emitting element of claim 3, wherein the reflective film electrode further comprises a diffusion barrier layer.

8. The light emitting element of claim 7, wherein the diffusion barrier layer comprises Ru, Ir, Re, Rh, Os, V, Ta, W, Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), RuO₂, VO₂, MgO, IrO₂, ReO₂, RhO₂, OsO₂, Ta₂O₃, WO₂, or any combination thereof.

9. The light emitting element of claim 7, wherein the thickness of the diffusion barrier layer is 50 Å

to 1000 Å

.

10. The light emitting element of claim 7, wherein the reflective film electrode further comprises a bonding layer.

11. The light emitting element of claim 10, wherein the bonding layer comprises a first bonding layer and a second bonding layer.

12. The light emitting element of claim 10, wherein the bonding layer comprises Ni, Cr, Ti, Pd, Ru, Ir, Rh, Re, Os, V, Ta, Au, Pd, Pt, or any combination thereof.

13. The light emitting element of claim 1, wherein the anti-reflective layer comprises ITO, SiO₂, Si₃N₄, or IZO.

14. The light emitting element of claim 1, wherein the anti-reflection layer extends beyond an edge of the nitride semiconductor structure.

15. The light emitting element of claim 1, wherein the metallic support layer comprises a multi-layered structure,

wherein the multi-layered structure comprises a first layer comprising Au, Ni, W, Mo, Cu, Al, Ta, Ag, Pt, Cr, or any combination thereof, and a second layer comprising Au, Ni, W, Mo, Cu, Al, Ta, Ag, Pt, Cr, and any combination thereof.

16. The light emitting element of claim 1, wherein the metallic support layer comprises a conductive ceramic film or a semiconductor doped with impurities.

17. The light emitting element of claim 16, wherein the metallic support layer comprises SrTiO₃ doped with Nb, ZnO doped with Al, ITO, IZO, Si doped with B, Si doped with As, or diamond doped with impurities.