III-V nitride substrate boule and method of making and using the same

• US 7,655,197 B2
• Filed: 02/19/2003
• Issued: 02/02/2010
• Est. Priority Date: 03/13/2000
• Status: Expired due to Fees

• Current Assignee: Wolfspeed, Inc.
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Vaudo, Robert P., Redwing, Joan M., Brandes, George R., Flynn, Jeffrey S., Tischler, Michael A.
• Primary Examiner(s): Warden; Jill
• Assistant Examiner(s): Chorbaji; Monzer R
• Application Number:
  US10/369,846
• Publication Number:
  US 20030157376A1
• Time in Patent Office: 2,540 Days
• Field of Search: 422/245.1, 422/251, 422/292, 422/307, 422/1, 422/245, 422/251.1, 422/145, 437/39, 437/100, 437/106, 437/48, 117/97, 117/88, 117/87, 117/952, 117/90, 117/95
• US Class Current: 422/292
• CPC Class Codes: C30B 23/00 Single-crystal growth by condensing evaporated or sublimed materials
• CPC Class Codes: C30B 25/00 Single-crystal growth by chemical reaction of reactive gases, e.g. chemical vapour-deposition growth
• CPC Class Codes: C30B 25/02 Epitaxial-layer growth
• CPC Class Codes: C30B 25/183 being provided with a buffer layer, e.g. a lattice matching layer
• CPC Class Codes: C30B 29/403 AIII-nitrides
• CPC Class Codes: C30B 29/406 Gallium nitride
• CPC Class Codes: H01L 21/02389 Nitrides
• CPC Class Codes: H01L 21/0243 Surface structure
• CPC Class Codes: H01L 21/02433 Crystal orientation
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/02576 N-type
• CPC Class Codes: H01L 21/02579 P-type
• CPC Class Codes: H01L 21/02581 Transition metal or rare earth elements
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

A boule formed by high rate vapor phase growth of Group III-V nitride boules (ingots) on native nitride seeds, from which wafers may be derived for fabrication of microelectronic device structures. The boule is of microelectronic device quality, e.g., having a transverse dimension greater than 1 centimeter, a length greater than 1 millimeter, and a top surface defect density of less than 10⁷ defects cm⁻². The Group III-V nitride boule may be formed by growing a Group III-V nitride material on a corresponding native Group III-V nitride seed crystal by vapor phase epitaxy at a growth rate above 20 micrometers per hour.

Claims

1. A single crystal article comprising:

an (Al,Ga,In)N seed crystal having a first growth surface, and

a microelectronic device quality (Al,Ga,In)N boule grown on said seed crystal, the boule having a thickness of at least 4 millimeters in a direction perpendicular to the first growth surface;

wherein the boule has a diameter greater than 1 centimeter, is substantially crack-free, and has a top surface defect density of less than 10⁷ defects cm<sup>−

2</sup>.

2. A microelectronic device structure comprising a substrate derived from the single crystal article of claim 1, and having a device fabricated on and/or in the substrate.

3. A single crystal article comprising:

an (Al,Ga,In)N seed crystal having a first growth surface, and

a microelectronic device quality (Al,Ga,In)N boule grown on said seed crystal, the boule having a thickness of at least 4 millimeters in a direction perpendicular to the first growth surface;

wherein the seed crystal has an orientation selected from the group consisting of c-axis, a-axis, m-axis, r-axis, and offcut less than 10 degrees from a primary crystal axis.

4. The single crystal article of claim 3, wherein the boule has a transverse area greater than 5 square centimeters.

5. The single crystal article of claim 4, wherein the boule has a thickness of greater than 5 millimeters in a direction perpendicular to said first growth surface.

6. The single crystal article of claim 3, wherein the boule is grown by VPE.

7. The single crystal article of claim 3, wherein the boule has a thickness greater than 10 millimeters in a direction perpendicular to said first growth surface.

8. The single crystal article of claim 3, grown from a native seed crystal, wherein the boule has an extremity with a greater transverse area than the seed crystal.

9. The single crystal article of claim 3, wherein the seed crystal has a c-axis orientation, and the first growth surface is either the N-face or (Al,Ga,In)-face of the c-axis-oriented seed crystal.

10. The single crystal article of claim 3, wherein the boule is of n-type.

11. The single crystal article of claim 3, wherein the boule is doped with a dopant species selected from the group consisting of silicon and germanium.

12. The single crystal article of claim 11, wherein the boule is doped with silicon dopant species derived from silane.

13. The single crystal article of claim 11, wherein the boule is doped with germanium dopant species derived from germane.

14. The single crystal article of claim 3, wherein the boule is doped to yield a room temperature electron concentration of from about 1E15 to about 5E19 cm⁻

3.

15. The single crystal article of claim 3, wherein the boule is doped to yield a room temperature electron concentration of from about 5E17 to about 1E19 cm⁻

3.

16. The single crystal article of claim 3, wherein the boule is of p-type.

17. The single crystal article of claim 16, wherein the boule is doped with a dopant species selected from the group consisting of beryllium, magnesium and zinc.

18. The single crystal article of claim 17, wherein the boule is doped using an organometallic source of the dopant species.

19. The single crystal article of claim 16, wherein the boule is doped to yield a room temperature hole concentration of from about 1E15 to about 1E 19 cm⁻

3.

20. The single crystal article of claim 16, wherein the boule is doped to yield a room temperature hole concentration of from about 5E17 to about 1E¹⁹ cm⁻

3.

21. The single crystal article of claim 3, wherein the boule is doped with a dopant species selected from the group consisting of vanadium, chromium, iron, arsenic, manganese, cobalt, nickel and copper.

22. The single crystal article of claim 21, wherein the boule is doped using a vapor source of the dopant species.

23. The single crystal article of claim 21, wherein the dopant species is derived from a solid source selected from the group consisting of p-type and deep level dopant solid sources.

24. The single crystal article of claim 21, wherein the boule has a resistivity greater than 1E3 ohm-cm.

25. The boule of claim 3, wherein the (Al, Ga, In) nitride comprises any of AlGaN, InGaN, AlInN, and AlInGaN.

26. The boule of claim 3, wherein the (Al, Ga, In) nitride comprises GaN.

27. The single crystal article of claim 3, doped by diffusion at temperature greater than 600 degrees C.

28. The single crystal article of claim 3, wherein prior to said growth the seed crystal was produced by an optical liftoff technique.

29. The single crystal article of claim 3, wherein prior to said growth the seed crystal was produced by growth of (Al,Ga,In)—

N on a sacrificial template and removal of the template by a removal technique selected from the group consisting of physical, thermal, etching, H-fracture and embrittlement removal techniques.

30. A microelectronic device structure comprising a substrate derived from the article of claim 3, and having a device fabricated on and/or in the substrate.

31. The microelectronic device structure of claim 30, wherein the device is selected from the group consisting of light emitting diodes and lasers.

32. The microelectronic device structure of claim 30, wherein the substrate has been cleaved.

33. The microelectronic device structure of claim 32, formed on free-standing material.

34. A plurality of wafers derived from the single crystal article of claim 3.

35. The article of claim 3, wherein the (Al,Ga,In)N seed crystal is devoid of any non-native substrate.

36. A single crystal article comprising:

an (Al,Ga,In)N seed crystal having a first growth surface, and

a microelectronic device quality (Al,Ga,In)N boule grown on said seed crystal, the boule having a thickness of at least 4 millimeters in a direction perpendicular to the first growth surface;

wherein the boule has a surface defect density of less than 10⁶ defects cm<sup>−

2</sup>.

37. The single crystal article of claim 36, wherein the boule has a surface defect density of less than 10⁴ defects cm⁻

2.

38. The kettle single crystal article of claim 36, having a diameter greater than 1 centimeter, and being substantially crack-free.

39. A microelectronic device structure comprising a substrate derived from the single crystal article of claim 36, and having a device fabricated on and/or in the substrate.

40. A (Al,Ga,In)N boule comprising crystalline seed material and boule material grown thereon, with an interlayer between said seed material and said boule material, the boule having a thickness of at least 4 millimeters in a direction perpendicular to a growth surface, wherein the boule is grown on a seed crystal having an orientation selected from the group consisting of c-axis, a-axis, m-axis, r-axis, offcut orientation offcut from 1 to 10 degrees from the primary crystal axis, N-face and (In,Al,Ga)-face.

41. A microelectronic device structure comprising a substrate derived from the boule of claim 40, and having a device fabricated on and/or in the substrate.

42. An (Al,Ga,In)N wafer derived from a single crystal article, the single crystal article including an (Al,Ga,In)N seed crystal having a first growth surface, and including a microelectronic device quality (Al,Ga,In)N boule grown on said seed crystal, the boule having a thickness of at least 4 millimeters in a direction perpendicular to the first growth surface, wherein the wafer is characterized by at least one of the following features (a) to (f):

(a) the wafer has an orientation offcut from 0.5 to 10 degrees from a primary crystal axis;

(b) the wafer has a surface with an RMS roughness less than 5 Angstroms over a 10×

10 micrometers² area;

(c) the wafer has a radius of curvature greater than 1 meter;

(d) the wafer has a flat oriented to better than +0.3 degrees;

(e) the wafer has a TTV of less than 20% of the average wafer thickness; and

(f) the wafer has a warp of less than 50 micrometers.

43. The wafer of claim 42, having an orientation selected from the group consisting of c-axis, a-axis, m-axis, r-axis.

44. The wafer of claim 42, having an orientation offcut from 0.5 to 10 degrees from a primary crystal axis.

45. of claim 42, having at least one of the N-face and (Al,Ga,In)-face of a c-axis-oriented wafer prepared for epitaxial growth.

46. The wafer of claim 42, parted from the (Al,Ga,In)N seed crystal by other than slicing or cutting.

47. The wafer of claim 42, having a surface with an RMS roughness less than 5 Angstroms over a 10×

10 micrometers² area.

48. The wafer of claim 42, having a radius of curvature greater than 1 meter.

49. The wafer of claim 42, having a flat oriented to better than +0.3 degrees.

50. The wafer of claim 42, having a flat produced by cleaving.

51. The wafer of claim 42, having a TTV of less than 20% of the average wafer thickness.

52. The wafer of claim 51, having a TTV of less than 5% of the average wafer thickness.

53. The wafer of claim 42, having a warp of less than 50 micrometers.

54. The wafer of claim 53, having a warp of less than 10 micrometers.

55. An article comprising the wafer of claim 42, and a microelectronic device structure disposed in or on said wafer.

56. The article of claim 55, wherein the microelectronic device structure is selected from the group consisting of light emitting diodes, laser diodes, ultraviolet photodetectors, high electron mobility transistors, bipolar transistor, heterojunction bipolar transistor, wavelength division multiplexing components, and high power rectifiers.

57. An (Al,Ga,In)N wafer having a surface with an RMS roughness less than 5 Angstroms over a 10×

10 micrometers² area.

58. The wafer of claim 57, having a radius of curvature greater than 1 meter.

59. The wafer of claim 57, having a flat oriented to better than +0.3 degrees.

60. The wafer of claim 57, having a flat produced by cleaving.

61. The wafer of claim 57, having a TTV of less than 20% of the average wafer thickness.

62. The wafer of claim 57, having a TTV of less than 5% of the average wafer thickness.

63. The wafer of claim 57, having a warp of less than 50 micrometers.

64. The wafer of claim 57, having a warp of less than 10 micrometers.

65. An article comprising the wafer of claim 57, and a microelectronic device structure disposed in or on said wafer.

66. The article of claim 65, wherein the microelectronic device structure is selected from the group consisting of light emitting diodes, laser diodes, ultraviolet photodetectors, high electron mobility transistors, bipolar transistors, heterojunction bipolar transistors, wavelength division multiplexing components, and high power rectifiers.