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

• US 7,964,884 B2
• Filed: 10/21/2005
• Issued: 06/21/2011
• Est. Priority Date: 10/22/2004
• Status: Active Grant

• Current Assignee: Postech Foundation, 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:
  US11/577,710
• Publication Number:
  US 20080006836A1
• Time in Patent Office: 2,069 Days
• Field of Search: 257/98, 257/99, 257/102, 257/103
• 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 P-type reflective film electrode on the metallic support layer;

a P-type semiconductor layer, an active layer and an N-type semiconductor layer sequentially formed on the P-type reflective film electrode;

an N-type electrode formed on the N-type semiconductor layer; and

a protective layer interposed directly between the P-type reflective film electrode and the P-type semiconductor layer.

3. The light emitting element as claimed in claim 1, further comprising an insulation film formed at least on a lateral side of the N-type semiconductor layer, and a metallic protective layer for protecting the P-type and N-type semiconductor layers.

4. The light emitting element as claimed in claim 1, wherein the metallic support layer has a multi-layered support structure.

5. The light emitting element as claimed in claim 1, wherein the protective layer is formed on a part of lateral and/or bottom sides of the N-type semiconductor layer, active layer and P-type semiconductor layer.

6. The light emitting element as claimed in claim 1, further comprising an anti-reflective layer wrapping around the P-type semiconductor layer, active layer and N-type semiconductor layer.

7. The light emitting element as claimed in claim 1, wherein the P-type reflective film electrode comprises a contact metallic layer, a reflective metallic layer, a diffusion barrier layer and a bonding metallic layer.

8. The light emitting element as claimed in claim 1, wherein the protective layer is formed on part of the P-type reflective film electrode and part of the P-type semiconductor layer.

9. The light emitting element as claimed in claim 1, wherein the metallic support layer is not wider than the P-type semiconductor layer, the active layer and the N-type semiconductor layer.

10. The light emitting device as claimed in claim 1, wherein the N-type electrode comprises a single electrode arranged substantially on a central portion of the N-type semiconductor layer.

2. A light emitting element, comprising:

a metallic support layer;

a reflective layer formed on the metallic support layer;

a P-type reflective film electrode formed in the form of a mesh on the reflective layer;

a P-type semiconductor layer, an active layer and an N-type semiconductor layer sequentially formed on the top of the reflective layer including the P-type reflective film electrode; and

an N-type electrode formed at a desired region on the N-type semiconductor layer,

wherein the reflective layer surrounds the P-type reflective film electrode by contacting the bottom and sides of the P-type reflective film electrode.

15. The light emitting device as claimed in claim 2, further comprising a second metallic support layer interposed directly between the metallic support layer and the reflective layer.

11. A light emitting element, comprising:

a metallic support layer;

a reflective layer formed on the metallic support layer;

a P-type reflective film electrode formed in the form of a mesh on the reflective layer;

a P-type semiconductor layer, an active layer and an N-type semiconductor layer sequentially formed on the top of the reflective layer including the P-type reflective film electrode;

an N-type electrode formed at a desired region on the N-type semiconductor layer; and

a protective layer interposed between the P-type reflective film electrode and the P-type semiconductor layer.

12. The light emitting device as claimed in claim 11, wherein the protective layer and a side of the reflective layer form a substantially planar surface.

13. The light emitting device as claimed in claim 11, wherein portions of the reflective layer contact the protective layer.

14. A light emitting element, comprising:

a metallic support layer;

a reflective layer formed on the metallic support layer;

a P-type reflective film electrode formed in the form of a mesh on the reflective layer;

a P-type semiconductor layer, an active layer and an N-type semiconductor layer sequentially formed on the top of the reflective layer including the P-type reflective film electrode; and

an N-type electrode formed at a desired region on the N-type semiconductor layer,

wherein the P-type reflective film electrode is directly on the reflective layer.