SEMICONDUCTOR LIGHT EMITTING DEVICE INCLUDING A WINDOW LAYER AND A LIGHT-DIRECTING STRUCTURE

• US 20100019260A1
• Filed: 07/24/2008
• Published: 01/28/2010
• Est. Priority Date: 07/24/2008
• Status: Active Grant

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: EPLER, John, Schekin, Oleg B., Neff, James G.
• Granted Patent: US 10,147,843 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2933/0083 Periodic patterns for optical field-shaping in or on the semiconductor body or semiconductor body package, e.g. photonic bandgap structures
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• CPC Class Codes: H01L 33/16 with a particular crystal structure or orientation, e.g. polycrystalline, amorphous or porous
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

A device includes a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region. The semiconductor structure is disposed between a window layer and a light-directing structure. The light-directing structure is configured to direct light toward the window layer; examples of suitable light-directing structures include a porous semiconductor layer and a photonic crystal. An n-contact is electrically connected to the n-type region and a p-contact is electrically connected to the p-type region. The p-contact is disposed in an opening formed in the semiconductor structure.

Claims

1. A device comprising:

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

a window layer;

a light-directing structure, the light-directing structure being configured to direct light toward the window layer; and

an n-contact electrically connected to the n-type region and a p-contact electrically connected to the p-type region;

wherein;

the semiconductor structure is disposed between the window layer and the light-directing structure; and

the light-directing structure is disposed on a surface of the n-type region; and

the p-contact is disposed in an opening formed in the semiconductor structure.

2. The device of claim 1 further comprising at least one transparent bonding layer disposed between the p-type region and the window layer.

3. The device of claim 2 wherein the bonding layer is conductive, is directly connected to the p-type region, and is one of a transparent conductive oxide, indium tin oxide, zinc oxide, and ruthenium oxide.

4. The device of claim 2 wherein a combined thickness of all layers disposed between the p-type region and the window layer is less than 2 μ

m.

5. The device of claim 2 wherein the p-contact is disposed on the bonding layer in an opening etched through the semiconductor structure to expose the bonding layer.

6. The device of claim 2 wherein the at least one transparent bonding layer is a transparent conductive oxide directly connected to the p-type region, the device further comprising an additional transparent bonding layer disposed between the at least one transparent bonding layer and the window layer.

7. The device of claim 6 further comprising a wavelength converting material disposed in the additional transparent bonding layer.

8. The device of claim 6 wherein an interface between the additional transparent bonding layer and the at least one transparent bonding layer is adapted to scatter light.

9. The device of claim 6 wherein the additional transparent bonding layer is one of a transparent conductive oxide, a non-conducting glass material, a dielectric material, silicon nitride, ITO, soda-lime glass, borosilicate glass, an organic material, benzocyclobutene, spin-on glass, and silicone.

10. The device of claim 1 wherein a bond between the window layer and the p-type region is substantially free of organic material.

11. The device of claim 1 wherein the window layer is one of an optical filter, sapphire, and glass.

12. The device of claim 1 wherein the window layer comprises a wavelength converting material configured to absorb light emitted by the light emitting layer and emit light of a different wavelength.

13. The device of claim 12 wherein the wavelength converting material is disposed in a ceramic layer.

14. The device of claim 1 wherein the light-directing structure comprises one of a porous semiconductor layer and a photonic crystal formed in a surface of the n-type region.

15. The device of claim 1 wherein the light emitting layer is a III-nitride layer.