Gallium nitride-based light emitting diode and method of manufacturing the same

• US 8,012,779 B2
• Filed: 07/24/2007
• Issued: 09/06/2011
• Est. Priority Date: 08/14/2006
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung LED Co., Ltd. (Samsung Electronics Co. Ltd.)
• Inventors: Oh, Bang Won, Baik, Doo Go, Choi, Seok Beom, Woo, Jong Gun
• Primary Examiner(s): Nguyen; Ha Tran T
• Assistant Examiner(s): Dehne; Aaron A
• Application Number:
  US11/878,360
• Publication Number:
  US 20080035953A1
• Time in Patent Office: 1,505 Days
• Field of Search: 438/46, 257/79
• US Class Current: 438/29
• CPC Class Codes: H01L 33/02 characterised by the semiconductor bodies
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers

Abstract

A vertical GaN-based LED comprises an n-electrode; an n-type GaN layer formed under the n-electrode, the n-type GaN layer having an irregular-surface structure which includes a first irregular-surface structure having irregularities formed at even intervals and a second irregular-surface structure having irregularities formed at uneven intervals, the second irregular-surface structure being formed on the first irregular-surface structure; an active layer formed under the n-type GaN layer; a p-type GaN layer formed under the active layer; a p-electrode formed under the p-type GaN layer; and a structure support layer formed under the p-electrode.

Claims

1. A vertical GaN-based LED comprising:

an n-electrode;

an n-type GaN layer formed under the n-electrode, the n-type GaN layer having an irregular-surface structure on a surface thereof, which includes a plurality of first irregular-surface structures formed at periodic intervals wherein each of the plurality of the first irregular-surface structures have irregularities formed at non-periodic intervals,

an active layer formed under the n-type GaN layer;

a p-type GaN layer formed under the active layer;

a p-electrode formed under the p-type GaN layer; and

a structure support layer formed under the p-electrode,

wherein each of the first irregular-surface structures has a hexahedron shape having an upper surface and a side surface, and the side surface of each of the first irregular-surface structures is devoid of the irregularities.

2. The vertical GaN-based LED according to claim 1 further comprising

a transparent conductive layer formed on the entire surface of the n-type GaN layer, the transparent conductive layer being positioned between the n-electrode and the n-type GaN layer.

3. A method of manufacturing a vertical GaN-based LED comprising:

sequentially forming an n-type GaN layer, an active layer, and a p-type GaN layer on a substrate;

forming a p-electrode on the p-type GaN layer;

forming a structure support layer on the p-electrode;

removing the substrate so as to expose the surface of the n-type GaN layer;

forming a plurality of first irregular-surface structures with-periodic intervals on the exposed surface of the n-type GaN layer;

forming irregularities with non-periodic intervals on each of the plurality of first irregular-surface structures; and

forming an n-electrode on the n-type GaN layer having the first irregular-surface structures formed thereon,

wherein each of the first irregular-surface structures has a hexahedron shape having an upper surface and a side surface, and the side surface of each of the first irregular-surface structures is devoid of the irregularities.

4. The method according to claim 3,

wherein the forming of the first irregular-surface structure includes:

forming a predetermined shape of photoresist pattern with even intervals on the exposed n-type GaN layer; and

selectively etching portions of the n-type GaN layer by using the photoresist pattern as an etching mask.

5. The method according to claim 3,

wherein the forming of the irregularities on each of the plurality of first irregular-surface structures is performed by using a dry-etching or wet-etching process.

6. The method according to claim 3 further comprising

forming a transparent conductive layer on the n-type GaN layer, before the forming of the n-electrode.

7. A method of manufacturing a vertical GaN-based LED comprising:

patterning the surface of a substrate into an irregularity pattern with even intervals;

forming an n-type GaN layer such that the surface of the n-type GaN layer coming in contact with the substrate patterned into the irregularity pattern has a plurality of first irregular-surface structures with periodic intervals in accordance with the irregularity pattern;

sequentially forming an active layer and a p-type GaN layer on the n-type GaN layer;

forming a p-electrode on the p-type GaN layer;

forming a structure support layer on the p-electrode;

removing the substrate so as to expose the first irregular-surface structure of the n-type GaN layer;

forming irregularities with non-periodic intervals on the exposed surface of the plurality of first irregular-surface structures; and

forming an n-electrode on the n-type GaN layer having the first irregular-surface structures formed thereon,

wherein each of the first irregular-surface structures have a hexahedron shape having an upper surface and a side surface, and the side surface of each of the first irregular-surface structures is devoid of the irregularities.

8. The method according to claim 7,

wherein the patterning of the substrate includes:

forming a predetermined shape of photoresist pattern with even intervals on the substrate; and

selectively etching portions of the substrate by using the photoresist pattern as an etching mask.

9. The method according to claim 7,

wherein the forming of the irregularities with non-periodic intervals on the exposed surface of the plurality of first irregular-surface structures is performed by a dry-etching or wet-etching process.

10. The method according to claim 7 further comprising

forming a transparent conductive layer on the n-type GaN layer, before the forming of the n-electrode.