Growth of non-polar M-plane III-nitride film using metalorganic chemical vapor deposition (MOCVD)

• US 8,795,440 B2
• Filed: 12/07/2011
• Issued: 08/05/2014
• Est. Priority Date: 05/31/2005
• Status: Active Grant

• Current Assignee: Japan Science & Technology Trading Co. Limited, Regents of the University of California (University of California)
• Original Assignee: Japan Science & Technology Trading Co. Limited, Regents of the University of California (University of California)
• Inventors: Imer, Bilge M., Speck, James S., DenBaars, Steven P., Nakamura, Shuji
• Primary Examiner(s): Chaudhuri, Olik
• Assistant Examiner(s): Parker, John M
• Application Number:
  US13/313,335
• Publication Number:
  US 20120074429A1
• Time in Patent Office: 972 Days
• Field of Search: 438/46, 438/767, 438/481, 438/590, 438/604, 257/79, 257/86, 257/98, 257/627
• US Class Current: 148/33.4
• CPC Class Codes: C30B 25/02 Epitaxial-layer growth
• CPC Class Codes: C30B 25/18 characterised by the substrate
• CPC Class Codes: C30B 29/403 AIII-nitrides
• CPC Class Codes: C30B 29/406 Gallium nitride
• CPC Class Codes: H01L 21/02378 Silicon carbide
• CPC Class Codes: H01L 21/02389 Nitrides
• CPC Class Codes: H01L 21/0242 Crystalline insulating materials
• CPC Class Codes: H01L 21/02433 Crystal orientation
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/02516 Crystal orientation
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/02609 Crystal orientation
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 21/02658 Pretreatments cleaning in general H01L21/02041

Abstract

A method of growing non-polar m-plane III-nitride film, such as GaN, AlN, AlGaN or InGaN, wherein the non-polar m-plane III-nitride film is grown on a suitable substrate, such as an m-SiC, m-GaN, LiGaO₂ or LiAlO₂ substrate, using metalorganic chemical vapor deposition (MOCVD). The method includes performing a solvent clean and acid dip of the substrate to remove oxide from the surface, annealing the substrate, growing a nucleation layer, such as aluminum nitride (AlN), on the annealed substrate, and growing the non-polar m-plane III-nitride film on the nucleation layer using MOCVD.

Claims

1. A III-nitride crystal, comprising:

a top surface having an area of least 5 micrometers by 5 micrometers, wherein;

the top surface has a non-polar m-plane orientation, and

a surface roughness of the top surface, as grown, is not more than 2.54 nanometers at least for the area of 5 micrometers by 5 micrometers, and

the III-nitride crystal has a crystalline quality characterized by an off-axis rocking curve having an off-axis full width at half maximum (FWHM) of no more than 0.38°

, as measured by X-ray diffraction.

2. The III-nitride crystal of claim 1, wherein:

the III-nitride crystal has a crystalline quality characterized by an on-axis rocking curve having an on-axis (1-100) full width at half maximum (FWHM) of;

no more than 0.22°

, for an a-mosaic of the III-nitride crystal, or

no more than 1.2°

, for a c-mosaic of the III-nitride crystal or

no more than 0.22°

, for an a-mosaic of the III-nitride crystal and no more than 1.2°

, for a c-mosaic of the III-nitride crystal, and

the rocking curves are measured by X-ray diffraction.

3. The III-nitride crystal of claim 2, wherein the off-axis is (10-12).

4. The III-nitride crystal of claim 1, wherein the III-nitride crystal is a Gallium Nitride crystal.

5. The III-nitride crystal of claim 1, wherein the III-nitride crystal comprises AlN, AlGaN or InGaN.

6. The III-nitride crystal of claim 1, further comprising:

a nucleation or first nitride layer grown on a substrate; and

the III-nitride crystal grown on the nucleation layer or the first nitride layer.

7. The III-nitride crystal of claim 6, wherein the nucleation layer or first nitride layer comprises aluminum nitride (AlN).

8. The III-nitride crystal of claim 1, wherein the III-nitride crystal is a device, wafer, substrate, or template.

9. The III-nitride crystal of claim 8, wherein the III-nitride crystal comprises Gallium Nitride.

10. The III-nitride crystal of claim 1, wherein the III-nitride crystal is sufficiently thick to be free-standing.

11. The III-nitride crystal of claim 1, further comprising a non-polar optoelectronic or electronic device grown on the top surface.

12. The III-nitride crystal of claim 1, wherein the III-nitride crystal is grown on a Silicon Carbide substrate.

13. The III-nitride crystal of claim 1, wherein the III-nitride crystal is grown on a Gallium Nitride substrate.

14. The III-nitride crystal of claim 1, wherein the III-nitride crystal is grown on a LiGaO₂ or LiAlO₂ substrate.

15. The III-nitride crystal of claim 1, wherein individual grains of the III-nitride crystal are not distinguishable based on height measurements of the surface.

16. The III-nitride crystal of claim 1, wherein the surface results from predominantly stepped growth.

17. The crystal of claim 1, wherein the top surface is a largest surface of the III-nitride crystal.

18. The III-nitride crystal of claim 1, wherein the top surface is planar.

19. The III-nitride crystal of claim 1, wherein the III-nitride crystal is an initial III-nitride crystal.

20. A device structure comprising the III-nitride crystal of claim 1, wherein:

the III-nitride crystal is a non-polar m-plane film having a crystalline quality characterized by a rocking curve having a full width at half maximum (FWHM) of no more than 0.22°

as measured by X-Ray diffraction, and

the top surface of the non-polar m-plane film is epitaxially grown.

21. The device structure of claim 20, wherein the non-polar m-plane III-nitride film comprises different III-nitride layers.

22. A device structure, comprising:

a non-polar m-plane III-nitride crystal, wherein;

the non-polar m-plane III-nitride crystal is grown on a surface of a substrate,

a subsequent non-polar m-plane III-nitride layer is grown on a top surface of the non-polar m-plane III-nitride crystal,

the top surface includes an area with a root mean square surface roughness of not more than 2.54 nanometers at least for an area of 5 micrometers by 5 micrometers, and

the III-nitride crystal has a crystalline quality characterized by an off-axis rocking curve having an off-axis full width at half maximum (FWHM) of no more than 0.38°

, as measured by X-ray diffraction.

23. A method for growing an III-nitride crystal, comprising:

growing a top surface of a III-nitride crystal using growth conditions, wherein;

the top surface has an area of least 5 micrometers by 5 micrometers,

the top surface has a non-polar m-plane orientation,

a surface roughness of the top surface, as grown, is not more than 2.54 nanometers

at least for the area of 5 micrometers by 5 micrometers,

the III-nitride crystal has a crystalline quality characterized by an off-axis rocking

curve having an off-axis full width at half maximum (FWHM) of no more than 0.38°

, as measured by X-ray diffraction.

24. The method of claim 23, wherein the growing is by Metal Organic Chemical Vapor Deposition using optimized growth conditions.

25. The method of claim 23, wherein the III-nitride crystal is Gallium Nitride or Aluminum Nitride, and the growing is at:

a V/III ratio between 200-5500,

a growth pressure between 50-760 Torr, and

a growth temperature of at least 1000°

C.

26. The method of claim 25, further comprising:

growing an Aluminum Nitride (AlN) layer on the substrate at a temperature over 1175°

C. and to a thickness below 150 nanometers; and

growing the III-nitride crystal on the AlN layer.

27. The method of claim 23, wherein the III-nitride crystal is Gallium Nitride and the growing is at a growth pressure below 100 Torr.

28. The method of claim 27, wherein the growing is at a V/III ratio below 700.

29. The method of claim 28, wherein the growing is at a temperature in a range of 1100°

C.-1160°

C.

30. The method of claim 23, further comprising:

growing a first nitride layer on a substrate at a temperature of at least 1000°

C., and growing the non-polar m-plane III-Nitride layer on the first nitride layer, at the temperature of at least 1000°

C.

31. The method of claim 30, wherein the first III-nitride layer comprises aluminum nitride (AlN) or Gallium Nitride.