ANTI-REFLECTED HIGH EFFICIENCY LIGHT EMITTING DIODE DEVICE

• US 20110215290A1
• Filed: 01/07/2005
• Published: 09/08/2011
• Est. Priority Date: 03/17/2004
• Status: Abandoned Application

• Current Assignee: Epiplus Co., Ltd.
• Original Assignee: Epiplus Co., Ltd.
• Inventors: Park, Jin-Soo, Kim, Seong-Han, Gong, Myeong-Kook, Cho, Hyeon-Ryong, Choi, Pun-Jae
• Application Number:
  US10/593,088
• Publication Number:
  US 20110215290A1
• Time in Patent Office: Days
• US Class Current: 257/13
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/38 with a particular shape

Abstract

The present invention is related to a light emitting diode device in which a fine prominence and depression is formed on a semiconductor layer to make an anti-reflection region. The light emitting diode device comprises, a substrate; a N-type semi-conductor layer; an active layer for generating light; P-type semiconductor layer; a first exposed region formed by etching the active layer and the P-type semiconductor layer to partly expose the N-type semiconductor layer; a first ohmic contact formed on the first exposed layer; a second ohmic contact formed on the P-type semiconductor layer, and having an opening to partly form a second exposed region on the P-type semiconductor layer, said second exposed layer being formed to partly have a ultra-fine prominence and depression.

Claims

1. A light emitting diode including a substrate, a N-type semiconductor layer, an active layer for generating light, and a P-type semiconductor layer, the light emitting diode comprising:

a first exposed region formed by etching the active layer and the P-type semiconductor layer to expose at least a part of the N-type semiconductor layer;

a first ohmic electrode formed on the first exposed layer;

a second ohmic electrode formed on the P-type semiconductor layer and having an opening at least a part of said P-type semiconductor layer having a second exposed region through said opening; and

said at least a part of P-type semiconductor layer being provided with an ultra-fine prominence and depression structure.

2. The light emitting diode as claimed in claim 1, wherein at least a part of the first exposed region excepting a portion having the first ohmic electrode has an ultra-fine prominence and depression structure.

4. The light emitting diode as claimed in claim 1, wherein the P-type semiconductor layer is GaN doped with Mg the N-type semiconductor layer is GaN doped with Si, and the active layer is GaN.

5. The light emitting diode as claimed in claim 1, wherein the ultra-fine prominence and depression structure is a cluster of cylinder type prominence and depression elements.

6. The light emitting diode as claimed in claim 5, wherein the cylinder type prominence and depression element is a cone type, a column type, or a column type having a depressed upper end.

7. The light emitting diode as claimed in claim 5, wherein a width of the cylinder type prominence and depression element is 0.005˜

3 μ

m, and a height is 0.1˜

1 μ

m.

8. The light emitting diode as claimed in claim 5, wherein a width of the cylinder type prominence and depression element is 0.01˜

0.5 μ

m, and a height is 0.2˜

0.7 μ

m.

9. The light emitting diode as claimed in claim 5, wherein a width of the cylinder type prominence and depression element is 0.01˜

2 times larger than a peak wavelength of the light emitting diode, and a height is 0.5˜

10 times larger than the peak wavelength.

10. The light emitting diode as claimed in claim 5, wherein a width of the cylinder type prominence and depression element is 0.1˜

1 times larger than a peak wavelength of the light emitting diode, and a height is 1˜

3 times larger than the peak wavelength.

11. The light emitting diode as claimed in claim 5, wherein a density of the cylinder type prominence and depression elements is 1˜

10000/μ

m².

12. The light emitting diode as claimed in claim 5, wherein a density of the cylinder type prominence and depression elements is 50˜

500/μ

m².

13. The light emitting diode as claimed in claim 5, wherein the cylinder type prominence and depression element is formed by depositing a metal or silicon compound on the semiconductor layer, heat-treating the deposited metal or silicon compound, and dry- or wet-etching the deposited metal or silicon compound.

14. The light emitting diode as claimed in claim 13, wherein the metal is any one or combinations selected from a group of Ag Al, Au, Cr, In, Ni, Pd, Pt and Ti.

15. The light emitting diode as claimed in claim 13, wherein a temperature for the heat-treating is ranged from 90°

C. to 400°

C.

16. The light emitting diode as claimed in claim 15, wherein the cylinder type prominence and depression element is formed by selectivity, said selectivity being partly changed due to a reaction of the metal and the semiconductor at time of etching.

3. A light emitting diode including a substrate, a N-type semiconductor layer, an active layer for generating light, a P-type semiconductor layer, a transparence metal (electrode), and a metal pad for wire bonding the light emitting diode comprising:

a first exposed region formed by etching the active layer and the P-type semiconductor layer to expose at least a part of the N-type semiconductor layer;

a first ohmic electrode formed on the first exposed layer; and

at least a part of said first exposed region excepting a portion having the first ohmic electrode being provided with an ultra-fine prominence and depression structure.