PHOTONIC CRYSTAL LIGHT EMITTING DEVICE AND MANUFACTURING METHOD OF THE SAME

• US 20090184334A1
• Filed: 07/30/2008
• Published: 07/23/2009
• Est. Priority Date: 07/30/2007
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Oh, Bang Won, Kim, Je Won, Kim, Yong Chun, Kim, Ja Yeon, Hwang, Seok Min, Lee, Dong Yul, Park, Seong Ju, Kwon, Min Ki
• Granted Patent: US 8,405,103 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• 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 33/42 Transparent materials

Abstract

There is provided a photonic crystal light emitting device including: a light emitting structure including first and second conductivity type semiconductor layers and an active layer interposed therebetween; a transparent electrode layer formed on the second conductivity type semiconductor layer, the transparent electrode layer having a plurality of holes arranged with a predetermined size and period so as to form a photonic band gap for light emitted from the active layer, whereby the transparent electrode layer includes a photonic crystal structure; and first and second electrode electrically connected to the first conductivity type semiconductor layer and the transparent electrode layer, respectively. The photonic crystal light emitting device has a transparent electrode layer formed of a photonic crystal structure defined by minute holes, thereby improved in light extraction efficiency.

Claims

1. A photonic crystal light emitting device comprising:

a light emitting structure including first and second conductivity type semiconductor layers and an active layer interposed therebetween;

a transparent electrode layer formed on the second conductivity type semiconductor layer, the transparent electrode layer having a plurality of holes arranged with a predetermined size and period so as to form a photonic band gap for light emitted from the active layer, whereby the transparent electrode layer comprises a photonic crystal structure; and

first and second electrodes electrically connected to the first conductivity type semiconductor layer and the transparent electrode layer, respectively.

2. The photonic crystal light emitting device of claim 1, wherein the transparent electrode layer is formed of a metal oxide.

3. The photonic crystal light emitting device of claim 1, wherein the transparent electrode layer is formed of a material selected from a group consisting of ITO, In₂O₃, SnO₂, MgO, Ga₂O₃, ZnO and Al₂O₃.

4. The photonic crystal light emitting device of claim 1, wherein the holes are filled with a material having refractivity different from refractivity of a material for the transparent electrode layer.

5. The photonic crystal light emitting device of claim 4, wherein the material filled in the holes is SiO₂.

6. The photonic crystal light emitting device of claim 1, wherein the holes each are shaped as one of a circle, a square and a hexagon.

7. The photonic crystal light emitting device of claim 1, wherein the second electrode is formed on a top of the transparent electrode layer, and the photonic crystal structure of the transparent electrode layer is formed in an area of the transparent electrode layer excluding a portion where the second electrode is formed.

8. The photonic crystal light emitting device of claim 1, wherein the first and second conductivity type semiconductor layers are n-type and p-type semiconductor layers, respectively.

9. The photonic crystal light emitting device of claim 1, wherein the first conductivity type semiconductor layer, the active layer and the second conductivity type layer are formed of a nitride.

10. A method of manufacturing a photonic crystal light emitting device, the method comprising:

forming a first conductivity type semiconductor layer, an active layer and a second conductivity type semiconductor layer sequentially on a substrate;

forming photoresist patterns on the second conductivity type semiconductor layer;

forming a transparent electrode layer on a portion of the second conductivity type semiconductor layer where the photo resist patterns are not formed;

removing the photo resist patterns; and

forming first and second electrodes to electrically connect to the first conductivity type semiconductor layer and the transparent electrode layer, respectively,

wherein portions of the second conductivity type semiconductor layer where the photo resist patterns are removed are arranged with a predetermined size and period so as to form a photonic band gap for light emitted from the active layer, thereby defining a photonic crystal structure together with the transparent electrode layer.

11. The method of claim 10, wherein the transparent electrode layer is formed of a metal oxide.

12. The method of claim 11, wherein the transparent electrode layer comprises one selected from a group consisting of ITO, In₂O₃, SnO₂, MgO, Ga₂O₃, ZnO and Al₂O₃.

13. A method of manufacturing a photonic crystal light emitting device, the method comprising:

forming a first conductivity type semiconductor layer, an active layer and a second conductivity type semiconductor layer sequentially on a substrate;

forming a photonic crystal structure layer on the second conductivity type semiconductor layer;

forming photo resist patterns on the photonic crystal structure layer;

forming photonic crystal patterns by removing a portion of the photonic crystal structure layer where the photo resist patterns are not formed;

forming a transparent electrode layer on the removed portion of the photonic crystal structure layer;

removing the photo resist patterns; and

forming first and second electrodes to electrically connect to the first conductivity type semiconductor layer and the transparent electrode layer, respectively,

wherein the photonic crystal patterns are arranged with a predetermined size and period so as to form a photonic band gap for light emitted from the active layer, thereby defining a photonic crystal structure together with the transparent electrode layer.

14. The method of claim 13, wherein the transparent electrode layer is formed of a metal oxide.

15. The method of claim 14, wherein the transparent electrode layer comprises one selected from a group consisting of ITO, In₂O₃, SnO₂, MgO, Ga₂O₃, ZnO and Al₂O₃.

16. The method of claim 13, wherein the photonic crystal structure layer is formed of a material having refractivity different from refractivity of a material for the transparent electrode layer.

17. The method of claim 16, wherein the photonic crystal structure layer is formed of SiO₂.