Light emitting device

• US 8,304,794 B2
• Filed: 10/31/2011
• Issued: 11/06/2012
• Est. Priority Date: 06/12/2007
• Status: Active Grant

• Current Assignee: Siphoton Incorporated
• Original Assignee: Siphoton Incorporated
• Inventors: Pan, Shaoher X.
• Primary Examiner(s): VU, HUNG K
• Application Number:
  US13/286,108
• Publication Number:
  US 20120043525A1
• Time in Patent Office: 372 Days
• Field of Search: 257/13, 257/14, 257/94, 257/95, 257/103, 257/E33.003, 257/E33.005, 257/E33.006, 257/E33.007, 257/E33.008, 257/E33.023, 257/E33.025, 257/627
• US Class Current: 257/95
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/24 of the light emitting region, e.g. non-planar junction
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

A light emitting device includes a substrate having a first surface and a second surface not parallel to the first surface, and a light emission layer disposed over the second surface to emit light. The light emission layer has a light emission surface which is not parallel to the first surface.

Claims

1. A light emitting device, comprising:

a silicon substrate having a first surface;

a trench having two surfaces formed beneath the first surface, the two surfaces of the trench are not parallel to the first surface, and wherein the first surface of the substrate is substantially parallel to the (100) crystal plane of the silicon and the surfaces of the trench are substantially parallel to the (111) crystal plane of the silicon;

a light emission layer formed over and parallel to the two surfaces of the trench to emit light.

2. The light emitting device of claim 1, wherein the two trench surfaces are each at an angle between 10 degrees and 90 degrees relative to the first surface.

3. The light emitting device of claim 1, wherein the trench comprises a third trench surface at a bottom of the trench, the third trench surface being substantially parallel to the first surface.

4. The light emitting device of claim 3, wherein the area ratio of the third trench surface to the total area of the two trench surfaces is smaller than 50%.

5. The light emitting device of claim 1, wherein the trench has two additional trench surfaces substantially parallel to the (111) crystal plane.

6. The light emitting device of claim 5, wherein the trench has an opening in the first surface of the substrate, and wherein the opening has a substantially rectangular shape.

7. The light emitting device of claim 1, wherein the trench has an opening in the first surface of the substrate, wherein the opening has a width in the range of 100 microns to 100 mm.

8. The light emitting device of claim 1, wherein the light emission layer comprises a quantum-well layer configured to emit light when an electric current is produced in the quantum-well layer.

9. The light emitting device of claim 1, further comprising a buffer layer between the substrate and the light emission layer.

10. The light emitting device of claim 1, further comprising additional trenches each having:

(1) two surfaces formed beneath the first surface, the two surfaces are not parallel to the first surface, and (2) a light emission layer disposed along the two surfaces to emit light.

11. The light emitting device of claim 1 wherein the angle between the first surface and each of the two trench surfaces is 54.7 degrees.