Surface treatment of a semiconductor light emitting device

• US 10,002,988 B2
• Filed: 09/22/2016
• Issued: 06/19/2018
• Est. Priority Date: 10/06/2011
• Status: Active Grant

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Inventors: Rong, Yiwen, Neff, James Gordon, Thang, Tak Seng
• Primary Examiner(s): Rodriguez, Armando
• Application Number:
  US15/272,902
• Publication Number:
  US 20170012170A1
• Time in Patent Office: 635 Days
• CPC Class Codes: H01L 2933/0025 relating to coatings
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/483 Containers
• CPC Class Codes: H01L 33/50 Wavelength conversion elements

Abstract

A semiconductor light-emitting device includes a semiconductor structure having a light-emitting region. A surface of the semiconductor structure has flattened peaks.

Claims

1. A method comprising:

roughening a light extracting surface of a semiconductor structure, the semiconductor structure comprising a light emitting layer; and

after said roughening, reducing the mean surface roughness of the light extracting surface.

2. The method of claim 1 wherein reducing the mean surface roughness of the light extracting surface comprises reducing the mean surface roughness by at least 10%.

3. The method of claim 1 wherein reducing the mean surface roughness of the light extracting surface comprises reducing the mean surface roughness by at least 30%.

4. The method of claim 1 wherein reducing the mean surface roughness of the light extracting surface comprises treating the light extracting surface with plasma.

5. The method of claim 1 further comprising:

growing the semiconductor structure on a growth substrate;

attaching the semiconductor structure to a mount; and

removing the growth substrate, wherein the light extracting surface is a surface revealed by removing the growth substrate.

6. The method of claim 1 wherein:

roughening a light extracting surface of a semiconductor structure comprises forming a plurality of peaks on the light extracting surface; and

reducing the mean surface roughness of the light extracting surface comprises flattening tops of at least a portion of the plurality of peaks.

7. The method of claim 1 further comprising disposing a wavelength converting material over the light extracting surface.

8. A method comprising:

roughening a light extracting surface of a semiconductor structure, the semiconductor structure comprising a light emitting layer, wherein said roughening forms surface features on the light extracting surface; and

after said roughening, reducing a height of the surface features.

9. The method of claim 8 wherein reducing a height of the surface features comprises reducing the height of the surface features by at least 20%.

10. The method of claim 8 wherein reducing a height of the surface features comprises reducing the height of the surface features by at least 40%.

11. The method of claim 8 wherein reducing a height of the surface features comprises treating the light extracting surface with plasma.

12. The method of claim 8 further comprising:

growing the semiconductor structure on a growth substrate;

attaching the semiconductor structure to a mount; and

removing the growth substrate, wherein the light extracting surface is a surface revealed by removing the growth substrate.

13. The method of claim 8 further comprising disposing a wavelength converting material over the light extracting surface.