Light-emitting diode device structure with Si x N y layer

• US 8,642,421 B2
• Filed: 01/20/2012
• Issued: 02/04/2014
• Est. Priority Date: 05/15/2008
• Status: Active Grant

• Current Assignee: Semileds Optoelectronics Company Limited (SemiLEDs Inc)
• Original Assignee: Semileds Optoelectronics Company Limited (SemiLEDs Inc)
• Inventors: Tran, Chuong Anh
• Primary Examiner(s): Sofocleous, Alexander
• Assistant Examiner(s): Garcia, Joannie A
• Application Number:
  US13/355,322
• Publication Number:
  US 20120112163A1
• Time in Patent Office: 746 Days
• Field of Search: 438/237, 438/328, 438/979, 438/FOR.157, 438/FOR.287, 438/FOR.416, 257/13, 257/576, 257/656, 257/910, 257/E25.032, 257/E27.051, 257/E27.046, 257/E31.084, 257/E31.105
• US Class Current: 438/237
• CPC Class Codes: H01L 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/0062 for devices with an active region comprising only III-V compounds
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer

Abstract

A light-emitting diode (LED) structure fabricated with a Si_xN_y layer responsible for providing increased light extraction out of a surface of the LED is provided. Such LED structures fabricated with a Si_xN_y layer may have increased luminous efficiency when compared to conventional LED structures fabricated without a Si_xN_y layer. Methods for creating such LED structures are also provided.

Claims

1. A method of increasing light extraction from a light-emitting diode (LED) device comprising;

forming a first n-doped layer on a carrier substrate;

forming a Si_xN_y mask on the first n-doped layer;

forming a second n-doped layer on the Si_xN_y mask;

forming an active layer configured to emit light on the second n-doped layer;

forming a p-doped layer on the active layer;

removing the carrier substrate; and

forming a plurality of structures on the second n-doped layer by removing the first n-doped and the Si_xN_y mask and then roughening a surface of the second n-doped layer.

2. The method of claim 1 wherein the forming the plurality of structures step comprises etching.

3. The method of claim 1 wherein the forming the plurality of structures step comprises photoelectrochemical (PEC) oxidation and etching.

4. The method of claim 1 wherein the Si_xN_y mask is configured to reduce dislocations in the second n-doped layer during the forming the plurality of structures step.

5. The method of claim 1 wherein the Si_xN_y mask is configured to reduce dislocations in the active layer during the forming the plurality of structures step.

6. The method of claim 1 wherein the Si_xN_y mask is configured to reduce dislocations in the p-doped layer during the forming the plurality of structures step.

7. The method of claim 1 wherein the Si_xN_y mask is configured to increase a density of the structures relative to forming the structures without the Si_xN_y mask.

8. The method of claim 1 wherein the Si_xN_y mask is configured to increase a surface area of the structures relative to forming the structures without the Si_xN_y mask.

9. The method of claim 1 wherein the forming the plurality of structures step comprises etching to remove portions of the second n-doped layer.

10. The method of claim 1 further comprising

forming a p-electrode on the p-doped layer.

11. The method of claim 1, further comprising:

forming an n-electrode on the second n-doped layer.

12. The method of claim 1 wherein the Si_xN_y mask is configured to reduce current leakage in the LED device.

13. A light-emitting diode (LED) device comprising:

a carrier substrate;

a first n-doped layer on the carrier substrate having a first dislocation density;

a Si_xN_y mask on the first n-doped layer;

a second n-doped layer on the Si_xN_y having a plurality of structures configured to increase light extraction and a second dislocation density lower than the first dislocation density, the Si_xN_y mask located between the first n-doped layer and the second n-doped layer and configured to lower the second dislocation density and form the structures with an increased density and surface area;

an active layer configured to emit light on the second n-doped layer; and

a p-doped layer on the active layer.

14. The LED device of claim 13 wherein the Si_xN_y mask is configured to reduce dislocations in the active layer.

15. The LED device of claim 13 wherein the Si_xN_y mask is configured to reduce dislocations in the p-doped layer.

16. The LED device of claim 13 further comprising:

a p-electrode on the p-doped layer.

17. The LED device of claim 13 further comprising:

an n-electrode on the second n-doped layer.

18. The LED device of claim 13 further comprising a metal layer on the p-doped layer.