Resonant cavity III-nitride light emitting devices fabricated by growth substrate removal

• US 20060014310A1
• Filed: 09/14/2005
• Published: 01/19/2006
• Est. Priority Date: 06/03/2004
• Status: Abandoned Application

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Inventors: Krames, Michael R., Epler, John E., Wierer, Jonathan J. Jr.
• Application Number:
  US11/227,416
• Publication Number:
  US 20060014310A1
• Time in Patent Office: Days
• US Class Current: 438/22
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• 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 33/465 with a resonant cavity structure

Abstract

A semiconductor light emitting device includes an n-type region, a p-type region, and light emitting region disposed between the n- and p-type regions. The n-type, p-type, and light emitting regions form a cavity having a top surface and a bottom surface. Both the top surface and the bottom surface of the cavity may have a rough surface. For example, the surface may have a plurality of peaks separated by a plurality of valleys. In some embodiments, the thickness of the cavity is kept constant by incorporating an etch-stop layer into the device, then thinning the layers of the device by a process that terminates on the etch-stop layer.

Claims

1. A method of forming a semiconductor light emitting device, the method comprising:

growing an epitaxial structure on a growth substrate, the epitaxial structure comprising;

an etch-stop layer; and

a stack of III-nitride epitaxial layers including a light emitting layer;

wherein the stack is grown over the etch-stop layer;

bonding a host substrate to the structure;

removing the growth substrate; and

thinning the structure by a process that terminates on the etch-stop layer.

2. The method of claim 1 wherein thinning comprises thinning by photoelectrochemical etching and the etch stop layer comprises AlGaN.

3. The method of claim 1 wherein thinning comprises thinning by photoelectrochemical etching and the etch stop layer comprises InGaN.

4. The method of claim 1 wherein a thickness of the structure after thinning is less than one micron.

5. The method of claim 1 wherein after thinning, a thickness of the structure at any point varies less than 5% from an average thickness.

6. The method of claim 1 wherein removing the growth substrate comprises etching away a sacrificial layer disposed between the growth substrate and an etch-stop layer.

7. The method of claim 6 wherein etching comprises etching by photoelectrochemical etching.

8. The method of claim 1 wherein:

the growth substrate comprises a layer of SiC and a layer of Si;

the stack is grown on the layer of SiC; and

removing the growth substrate comprises etching away the layer of Si.

9. The method of claim 8 wherein the growth substrate further comprises a layer of an oxide of silicon disposed between the layer of SiC and the layer of Si.

10. The method of claim 9 wherein removing the growth substrate comprises etching away the layer of Si and the layer of an oxide of silicon.

11. The method of claim 1 further comprising removing the etch-stop layer after thinning.