Granted Patent B2

US 8,076,682 · App. 12/506,632 · Granted Dec 13, 2011

Abstract

Claims (16)

1. A device comprising:

a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region; and

a p-electrode disposed on a portion of the p-type region, the p-electrode comprising:

a reflective first material in direct contact with a first portion of the p-type region; and

a second material in direct contact with a second portion of the p-type region adjacent to the first portion;

wherein the first material and second material are different materials and are formed in planar layers of substantially the same thickness.

2. The device of claim 1 wherein the first material comprises silver.

3. The device of claim 1 wherein the second material comprises aluminum.

4. The device of claim 1 wherein the second material comprises one of an aluminum alloy, an aluminum metal stack, AlTi, an Al 2 O 3 /Al bilayer, and a SiO 2 /Al bilayer.

5. The device of claim 1 wherein:

a portion of the p-type region and light emitting layer are etched away to reveal a portion of the n-type region; and

a remaining portion of the p-type region forms a mesa;

wherein the second material is disposed between the first material and an edge of the mesa.

6. The device of claim 1 wherein the p-electrode further comprises a third material disposed over the first and second material, wherein the third material is configured to prevent migration of the first material.

7. The device of claim 1 wherein the p-electrode further comprises a third material disposed over the first and second material, wherein a bottom surface of the third material is in direct contact with both the first material and the second material.

8. The device of claim 6 wherein the third material comprises titanium and tungsten.

Assignments (8)