Polarization-reversed III-nitride light emitting device

• US 7,804,100 B2
• Filed: 03/14/2005
• Issued: 09/28/2010
• Est. Priority Date: 03/14/2005
• Status: Active Grant

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Philips Lumileds Lighting Company LLC (Apollo Global Management, Inc.), Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Wierer, Jonathan J. Jr., Krames, Michael R., Epler, John E., Craford, M. George
• Primary Examiner(s): Parker; Kenneth A
• Assistant Examiner(s): Kim; Jay C
• Application Number:
  US11/080,022
• Publication Number:
  US 20060202215A1
• Time in Patent Office: 2,024 Days
• Field of Search: 257/94, 257/E33.025, 257/E33.034, 257/E21.122, 257/E21.087, 257/E21.088, 257/96, 257/E21.567, 257/E33.028, 257/E33.03, 257/E33.033, 438/455
• US Class Current: 257/94
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/16 with a particular crystal structure or orientation, e.g. polycrystalline, amorphous or porous
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01S 2304/00 Special growth methods for semiconductor lasers
• CPC Class Codes: H01S 5/0213 Sapphire, quartz or diamond based substrates
• CPC Class Codes: H01S 5/0215 Bonding to the substrate
• CPC Class Codes: H01S 5/0217 Removal of the substrate
• CPC Class Codes: H01S 5/02208 characterised by the shape of the housings
• CPC Class Codes: H01S 5/320225 polar orientation
• CPC Class Codes: H01S 5/32341 blue laser based on GaN or GaP

Abstract

A device structure includes a III-nitride wurtzite semiconductor light emitting region disposed between a p-type region and an n-type region. A bonded interface is disposed between two surfaces, one of the surfaces being a surface of the device structure. The bonded interface facilitates an orientation of the wurtzite c-axis in the light emitting region that confines carriers in the light emitting region, potentially increasing efficiency at high current density.

Claims

1. A structure comprising:

a device structure comprising a III-nitride light emitting region disposed between a p-type region and an n-type region, the light emitting region comprising a wurtzite crystal structure; and

a non-III-nitride material disposed between two surfaces, wherein;

one of the surfaces is a surface of a wurtzite crystal portion of the device structure, the wurtzite crystal portion of the device structure comprising alternating layers of group III atoms and group V atoms, wherein the surface of the wurtzite crystal portion of the device structure comprises a surface of a layer of group III atoms; and

the other of the surfaces is a surface of a wurtzite crystal portion of a second structure, the wurtzite crystal portion of the second structure comprising alternating layers of group III atoms and group V atoms, wherein the surface of the wurtzite crystal portion of the second structure comprises a surface of a layer of group III atoms; and

the non-III-nitride material is in direct contact with the two surfaces;

wherein across an interface disposed between the light emitting region and the p-type region, a wurtzite c-axis, defined as pointing from a nitrogen face of a III-nitride unit cell to a group III atom face of the III-nitride unit cell, points toward the light emitting region.

2. The structure of claim 1 wherein the two surfaces are both GaN surfaces.

3. The structure of claim 1 wherein one of the two surfaces is selected from the group of GaN, AlN, and InGaN.

4. The structure of claim 1 wherein the surface of the wurtzite crystal portion of the device structure is a III-nitride surface that is one of p-type, n-type, and undoped.

5. The structure of claim 1 wherein one of the two surfaces is textured.

6. The structure of claim 5 wherein the textured surface comprises a periodic array of holes formed in the textured surface.

7. The structure of claim 6 wherein the periodic array of holes has a lattice constant between 0.1λ

and 4λ

, wherein λ

is a wavelength of light in the light emitting region.

8. The structure of claim 1 wherein the non-III-nitride material is a metal layer.

9. The structure of claim 1 wherein the non-III-nitride material is a metal-semiconductor alloy.

10. The structure of claim 1 further comprising contacts electrically connected to the n-type region and the p-type region.

11. The structure of claim 1 further comprising:

a mesa including a portion of the light emitting region; and

laser facets disposed on opposite ends of the mesa.

12. The structure of claim 1 wherein the device structure and the second structure are separately-grown III-nitride structures.

13. The structure of claim 8 wherein the metal layer comprises one of Zn and Sn.

14. The structure of claim 9 wherein the metal-semiconductor alloy comprises Al.

15. The structure of claim 1 wherein the non-III-nitride material is a dielectric.

16. The structure of claim 1 wherein the non-III-nitride material is an oxide of silicon.