Lateral growth method for defect reduction of semipolar nitride films

• US 8,148,244 B2
• Filed: 07/13/2006
• Issued: 04/03/2012
• Est. Priority Date: 07/13/2005
• Status: Active Grant

• Current Assignee: Japan Science And Technology Agency
• Original Assignee: Japan Science And Technology Agency, Regents of the University of California (University of California)
• Inventors: Baker, Troy J., Haskell, Benjamin A., Speck, James S., Nakamura, Shuji
• Primary Examiner(s): Landau, Matthew
• Assistant Examiner(s): MCCALL SHEPARD, SONYA D
• Application Number:
  US11/486,224
• Publication Number:
  US 20070015345A1
• Time in Patent Office: 2,091 Days
• Field of Search: 257/E21.133, 257E21131-E21132, 438/481
• US Class Current: 438/481
• CPC Class Codes: C30B 25/02 Epitaxial-layer growth
• CPC Class Codes: C30B 29/40 AIIIBV compounds wherein A is B, Al, Ga, In or Tl and B is N, P, As, Sb or Bi
• CPC Class Codes: H01L 21/0237 Materials
• CPC Class Codes: H01L 21/02378 Silicon carbide
• CPC Class Codes: H01L 21/0242 Crystalline insulating materials
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/02513 Microstructure
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/02609 Crystal orientation
• CPC Class Codes: H01L 21/02639 Preparation of substrate for selective deposition
• CPC Class Codes: H01L 21/02647 Lateral overgrowth
• CPC Class Codes: H01L 21/0265 Pendeoepitaxy

Abstract

A lateral growth method for defect reduction of semipolar nitride films. The process steps include selecting a semipolar nitride plane and composition, selecting a suitable substrate for growth of the semipolar nitride plane and composition, and applying a selective growth process in which the semipolar nitride nucleates on some areas of the substrate at the exclusion of other areas of the substrate, wherein the selective growth process includes lateral growth of nitride material by a lateral epitaxial overgrowth (LEO), sidewall lateral epitaxial overgrowth (SLEO), cantilever epitaxy or nanomasking.

Claims

1. A method of defect reduction for a semipolar nitride film, comprising:

performing a lateral growth of a semipolar nitride over a mask or gaps on or above a top surface of a substrate, to reduce defect density in the semipolar nitride, resulting in the semipolar nitride film having less than 2 ×

10⁹ cm<sup>−

2</sup> threading dislocations and a top surface of the semipolar nitride film that is a semipolar plane, wherein the top surface of the semipolar nitride film is planar and parallel to the top surface of the substrate.

2. The method of claim 1, wherein the lateral growth is a lateral epitaxial overgrowth (LEO).

3. The method of claim 1, wherein the lateral growth is a sidewall lateral epitaxial overgrowth (SLEO).

4. The method of claim 1, wherein the lateral growth is a cantilever epitaxy.

5. The method of claim 1, wherein the lateral growth is a nanomasking.

6. The method of claim 1, wherein the step of performing the lateral growth comprises the steps of:

selecting a semipolar nitride plane and composition;

selecting a suitable substrate for growth of the semipolar nitride plane and composition; and

applying a selective growth process in which the semipolar nitride nucleates on some areas of the substrate or template at the exclusion of other areas of the substrate or template due to the mask or gaps, wherein the selective growth process includes the lateral growth of nitride material.

7. A device fabricated using the method of claim 1.

8. The method of claim 1, resulting in the semipolar nitride film comprising less than 2 ×

10⁵ cm<sup>−

1</sup> basal plane stacking faults.

9. The method of claim 1, wherein the semipolar nitride film is a base layer for subsequent semipolar nitride device growth.

10. The method of claim 6, wherein the step of applying comprises applying a masking material that the nitride material does not adhere to during the selective growth process.

11. The method of claim 6, wherein the step of applying comprises defining elevated regions to act as nucleation sites for the nitride material.

12. The method of claim 6, wherein the lateral growth of the nitride material proceeds until adjacent islands or stripes of the nitride material merge or coalesce.

13. The method of claim 6, wherein the lateral growth of the nitride material results in uncoalesced laterally grown nitride material.

14. The method of claim 6, further comprising performing the lateral growth multiple times.

15. The method of claim 10, wherein the nitride material adheres to the substrate or template.

16. A semipolar nitride film, laterally grown over a mask or gaps on or above a top surface of a substrate, having less than 2 ×

10⁹ cm<sup>−

2</sup> threading dislocations and a top surface that is a semipolar plane, wherein the top surface of the semipolar nitride film is planar and parallel to the top surface of the substrate.

17. The film of claim 16, wherein the semipolar nitride film is a base layer for subsequent semipolar nitride device growth.

18. A semipolar nitride film, laterally grown over the mask or gaps on or above a top surface of a substrate, having less than 2 ×

10⁵ cm<sup>−

1</sup> basal plane stacking faults and a top surface that is a semipolar plane, wherein the top surface of the semipolar nitride film is planar and parallel to the top surface of the substrate.

19. The film of claim 18, wherein the semipolar nitride film is a base layer for subsequent semipolar nitride device growth.