Light emitting diode and fabrication method thereof

• US 7,358,537 B2
• Filed: 03/02/2005
• Issued: 04/15/2008
• Est. Priority Date: 03/19/2004
• Status: Active Grant

• Current Assignee: Transpacific IP Group Limited
• Original Assignee: Industrial Technology Research Institute
• Inventors: Tsay, Jenq-Dar, Chuo, Chang-Cheng, Yeh, Wen-Yung, Chi, Jim-Yong, Hsu, Jung-Tsung
• Primary Examiner(s): Picardat; Kevin M
• Application Number:
  US11/069,567
• Publication Number:
  US 20050221527A1
• Time in Patent Office: 1,140 Days
• Field of Search: 257/79, 257/94, 257/91, 257/95, 257/98, 257/13
• US Class Current: 257/95
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers

Abstract

A light emitting diode (LED). The LED comprises a LED chip comprising an n-type semiconductor layer, a active layer and a p-type semiconductor layer. An n-type ohmic contact electrode and a p-type ohmic contact electrode electrically contact the n-type semiconductor layer and the p-type semiconductor layer respectively. An AlGaInN thick film is on the LED chip, and the AlGaInN thick film has an oblique side and a textured top surface.

Claims

1. A light emitting diode (LED), comprising:

a LED chip comprising a n-type semiconductor layer, an active layer and a p-type semiconductor layer;

an n-type ohmic contact electrode electrically contacting the n-type semiconductor layer;

a p-type ohmic contact electrode electrically contacting the p-type semiconductor layer; and

an AlGaInN thick film on the LED chip, and the AlGaInN thick film has an oblique side and a textured top surface.

2. The light emitting diode (LED) as claimed in claim 1, wherein the AlGaInN thick film is Al_XGa_(1-X-Y)In_YN (0≦

X, Y<

1 and 0≦

X+Y<

1) thick film.

3. The light emitting diode (LED) as claimed in claim 1, wherein the AlGaInN thick film is thicker than 20 μ

m.

4. The light emitting diode (LED) as claimed in claim 1, wherein the AlGaInN thick film thickness is about 20˜

100 μ

m.

5. The light emitting diode (LED) as claimed in claim 1, wherein the AlGaInN thick film internal diameter exceeds 150 μ

m.

6. The light emitting diode (LED) as claimed in claim 1, wherein the AlGaInN thick film internal diameter is about 200˜

1000 μ

m.

7. The light emitting diode (LED) as claimed in claim 1, wherein the bottom shape of AlGaInN thick film comprises a polygon, a circle or an ellipse.

8. The light emitting diode (LED) as claimed in claim 7, wherein the polygon comprises a quadrangle or a hexagon.

9. The light emitting diode (LED) as claimed in claim 1, wherein the included angle between AlGaInN thick film bottom and oblique side is about 43˜

62°

.

10. The light emitting diode (LED) as claimed in claim 1, wherein the textured top surface comprises a convex structure or a concave structure.

11. The light emitting diode (LED) as claimed in claim 10, wherein the shape of convex structure or concave structure comprises a polygon, a circle or an ellipse.

12. The light emitting diode (LED) as claimed in claim 10, wherein the shape size of convex structure or concave structure is smaller than the LED chip size.

13. The light emitting diode (LED) as claimed in claim 12, wherein the shape size of convex structure or concave structure is about 1 nm˜

500 μ

m.

14. The light emitting diode (LED) as claimed in claim 10, wherein the convex structure or the concave structure has a sidewall vertical or oblique to its bottom.

15. The light emitting diode (LED) as claimed in claim 10, wherein the convex structure or the concave structure is a matrix.

16. The light emitting diode (LED) as claimed in claim 15, wherein the period of matrix is smaller than the LED chip size.

17. The light emitting diode (LED) as claimed in claim 16, wherein the period is about 1 nm˜

500 μ

m.

18. The light emitting diode (LED) as claimed in claim 10, wherein the height difference of convex structure or concave structure is less than the AlGaInN thick film thickness.

19. The light emitting diode (LED) as claimed in claim 10, wherein the height difference of convex structure or concave structure is from 1 nm to the AlGaInN thick film thickness.