Light-emitting diode incorporating an array of light extracting spots

• US 20070295951A1
• Filed: 06/26/2006
• Published: 12/27/2007
• Est. Priority Date: 06/26/2006
• Status: Abandoned Application

• Current Assignee: Tekcore Co Limited (Tekcore)
• Original Assignee: Tekcore Co Limited (Tekcore)
• Inventors: Chyi, Jen-Inn, Chen, Shih-Ling, Chang, Jui-Cheng, Chen, Tsung-Liang, Lee, Chia-Ming
• Application Number:
  US11/474,878
• Publication Number:
  US 20070295951A1
• Time in Patent Office: Days
• US Class Current: 257/14
• 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 33/02 characterised by the semiconductor bodies
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate

Abstract

A light-emitting diode includes an optical layer formed in an array of substantially equidistant light extracting spots integrated to its multi-layer structure. The array of light extracting spots includes a distribution of juxtaposed hexagon patterns. The layer thickness of the light extracting spots is less than 800 Å, and preferably around 500 Å.

Claims

1. A light-emitting diode, comprising:

a multi-layer structure including a plurality of nitride semiconductor layers stacked over a surface of a substrate, wherein the multi-layer structure includes a light-emitting layer;

a plurality of electrodes for applying a driving current through the multi-layer structure; and

an optical layer integrated to the multi-layer structure, wherein the optical layer forms an array of substantially equidistant light extracting spots.

2. The light-emitting diode according to claim 1, wherein the light extracting spots have a layer thickness less than about 800 Å

.

3. The light-emitting diode according to claim 1, wherein the optical layer is made of a material compound including SiO_x, Si_xN_y, SiC, SiO_xN_y, ZnSe, TiO₂, or Ta₂O₅, where x and y are chemical element ratio numbers.

4. The light-emitting diode according to claim 1, wherein the array of light extracting spots is arranged at an interface between two material layers of the multi-layer structure.

5. The light-emitting diode according to claim 1, wherein the array of the light extracting spots includes a distribution of the light extracting spots in juxtaposed hexagon patterns.

6. The light-emitting diode according to claim 5, wherein the light extracting spots are placed at the corners and centre of each hexagon pattern.

7. The light-emitting diode according to claim 1, wherein one light extracting spot has a hexagonal shape.

8. The light-emitting diode according to claim 1, wherein a luminous intensity of the light-emitting diode is above about 150 mcd.

9. A process of forming a light-emitting diode, comprising:

forming a multi-layer structure including at least one light-emitting layer;

forming electrodes for supplying a driving current through the multi-layer structure; and

forming an optical layer integrated to the multi-layer structure, wherein the optical layer includes an array of substantially equidistant light extracting spots.

10. The process according to claim 9, wherein the light extracting spots have a layer thickness less than about 800 Å

.

11. The process according to claim 9, wherein forming an optical layer integrated to the multi-layer structure includes forming the optical layer at an interface between two layers of the multi-layer structure.

12. The process according to claim 11, wherein forming an optical layer integrated to the multi-layer structure comprises:

forming an optical layer over a surface of a substrate;

patterning the optical layer to form an array of substantially equidistant light extracting spots; and

stacking a plurality of layers including the light-emitting layer over the optical layer.

13. The process according to claim 12, wherein stacking a plurality of layers over the optical layer includes:

forming a buffer layer covering the optical layer; and

forming a plurality of nitride semiconductor layers on the buffer layer.

14. The process according to claim 12, wherein patterning the optical layer to form an array of substantially equidistant light extracting spots includes performing a photolithography to form a photoresist pattern, and etching through the photoresist pattern.

15. The process according to claim 9, wherein the optical layer is made of a material composition including SiO_x, SiN_x, Si₃N₄, SiC, SiO_xN_y, ZnSe, TiO₂, or Ta₂O₅, where x and y are chemical element ratio numbers.

16. The process according to claim 9, wherein the array of substantially equidistant light extracting spots includes a distribution of the light extracting spots in juxtaposed hexagon patterns.

17. The process according to claim 16, wherein the light extracting spots are placed at the corners and centre of each hexagon pattern.

18. The process according to claim 9, wherein at least one light extracting spot has a hexagonal shape.

19. The process according to claim 9, wherein the light-emitting diode has a luminous intensity above about 150 mcds.