METHOD FOR GROWTH OF SEMIPOLAR (AL,IN,GA,B)N OPTOELECTRONIC DEVICES

• US 20110012234A1
• Filed: 09/24/2010
• Published: 01/20/2011
• Est. Priority Date: 02/17/2006
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Nakamua, Shuji, Kaeding, John F., Zhong, Hong, Speck, James S., Sharma, Rajat, DenBaars, Steven P.
• Granted Patent: US 8,203,159 B2
• Time in Patent Office: Days
• US Class Current: 257/615
• CPC Class Codes: C30B 25/186 being specially pre-treated by, e.g. chemical or physical means
• CPC Class Codes: C30B 29/403 AIII-nitrides
• CPC Class Codes: H01L 21/02389 Nitrides
• CPC Class Codes: H01L 21/0242 Crystalline insulating materials
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/02647 Lateral overgrowth
• CPC Class Codes: H01L 21/02658 Pretreatments cleaning in general H01L21/02041
• CPC Class Codes: H01L 29/2003 Nitride compounds
• CPC Class Codes: H01L 29/778 with two-dimensional charge carrier gas channel, e.g. HEMT ; with two-dimensional charge-carrier layer formed at a heterojunction interface H01L29/803 takes precedence
• CPC Class Codes: H01L 31/0236 Special surface textures
• CPC Class Codes: H01L 31/18 Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
• CPC Class Codes: H01L 33/0075 comprising nitride compounds
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

A method of fabricating an optoelectronic device, comprising growing an active layer of the device on an oblique surface of a suitable material, wherein the oblique surface comprises a facetted surface. The present invention also discloses a method of fabricating the facetted surfaces. One fabrication process comprises growing an epitaxial layer on a suitable material, etching the epitaxial layer through a mask to form the facets having a specific crystal orientation, and depositing one or more active layers on the facets. Another method comprises growing a layer of material using a lateral overgrowth technique to produce a facetted surface, and depositing one or more active layers on the facetted surfaces. The facetted surfaces are typically semipolar planes.

Claims

1. An optoelectronic device, comprising:

(a) one or more oblique or facetted surfaces formed on a substrate or template, wherein the oblique or facetted surfaces are semi-polar planes or non-polar planes;

(b) one or more active layers formed epitaxially on the oblique or facetted surfaces or on one or more epitaxial layers formed on the oblique or facetted surfaces,

(c) wherein at least one of the active layers, epitaxial layers, substrate, or template, is comprised of (Al, Ga, In)N-based material.

2. The device of claim 1, wherein the surface of the substrate or template is c-plane before the oblique or facetted surfaces are formed.

3. The device of claim 1, wherein the oblique or facetted surfaces do not all have the same orientation.

4. The device of claim 1, wherein the oblique or facetted surfaces have an inclination angle in a range from 25 to 50 degrees.

5. The device of claim 1, wherein the oblique or facetted surfaces are formed with an inclination angle larger than desired because subsequent layers deposited on the oblique or facetted surfaces reduce the inclination angle.

6. The device of claim 1, wherein the oblique or facetted surfaces are etched oblique or facetted surfaces.

7. The device of claim 6, wherein:

(1) the etched oblique or facetted surfaces have a maximum depth in a range between 1 nanometer and 10 microns, which determines a surface area of the oblique or facetted surfaces; and

(2) the surface area of the oblique or facetted surfaces have a width in a range between 3 and 10 microns, which determines an angle of inclination of the oblique or facetted surfaces.

8. The device of claim 1, wherein the oblique or facetted surfaces are sidewalls or facets of trenches, grooves, or pits in the surface of the substrate or template.

9. The device of claim 1, wherein the oblique or facetted surfaces are surfaces of epitaxial lateral overgrowths on the surface of the substrate or template.

10. A method for fabricating an optoelectronic device, comprising:

(a) forming one or more oblique or facetted surfaces on a substrate or template, wherein the oblique or facetted surfaces are semi-polar planes or non-polar planes;

(b) forming one or more active layers epitaxially on the oblique or facetted surfaces or on one or more epitaxial layers formed on the oblique or facetted surfaces,

(c) wherein at least one of the active layers, epitaxial layers, substrate, or template, is comprised of (Al, Ga, In)N-based material.

11. The method of claim 10, wherein the surface of the substrate or template is c-plane before the oblique or facetted surfaces are formed.

12. The method of claim 10, wherein the oblique or facetted surfaces do not all have the same orientation.

13. The method of claim 10, wherein the oblique or facetted surfaces have an inclination angle in a range from 25 to 50 degrees.

14. The method of claim 10, wherein the oblique or facetted surfaces are formed with an inclination angle larger than desired because subsequent layers deposited on the oblique or facetted surfaces reduce the inclination angle.

15. The method of claim 10, wherein the oblique or facetted surfaces are etched oblique or facetted surfaces.

16. The method of claim 15, wherein:

(1) the etched oblique or facetted surfaces have a maximum depth in a range between 1 nanometer and 10 microns, which determines a surface area of the oblique or facetted surfaces; and

(2) the surface area of the oblique or facetted surfaces have a width in a range between 3 and 10 microns, which determines an angle of inclination of the oblique or facetted surfaces.

17. The method of claim 10, wherein the oblique or facetted surfaces are sidewalls or facets of trenches, grooves, or pits in the surface of the substrate or template.

18. The method of claim 10, wherein the oblique or facetted surfaces are surfaces of epitaxial lateral overgrowths on the surface of the substrate or template.

19. A device fabricated using the method of claim 10.