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

• US 20030157376A1
• Filed: 02/19/2003
• Published: 08/21/2003
• Est. Priority Date: 03/13/2000
• Status: Active Grant

• Current Assignee: Wolfspeed, Inc.
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Brandes, George R., Vaudo, Robert P., Redwing, Joan M., Flynn, Jeffrey S., Tischler, Michael A.
• Granted Patent: US 7,655,197 B2
• Time in Patent Office: Days
• US Class Current: 428/698
• 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 microelectronic device quality (Al,Ga,In) N boule.

2. The boule of claim 1, having a transverse area greater than 5 square centimeters.

3. The boule of claim 2, having a length of greater than 5 mm.

4. The boule of claim 1, grown from native seed crystal.

5. The boule of claim 1, grown by VPE.

6. The boule of claim 1, grown from native seed crystal, having a diameter greater than 1 centimeter, and a length greater than 1 millimeter, which is substantially crack-free and has a top surface defect density of less than 10⁷ defects cm⁻

2.

7. The boule of claim 1, having a length greater than 4 millimeters.

8. The boule of claim 1, having a length greater than 10 millimeters.

9. The boule of claim 1, grown from a native seed crystal, wherein the boule has an extremity with a greater transverse area than the seed crystal.

10. The boule of claim 1, grown on a seed crystal having 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.

11. The boule of claim 1, grown on the N-face or (Al,Ga,In)-face of a c-axis-oriented seed crystal.

12. The boule of claim 1, of n-type.

13. The boule of claim 1, doped with a dopant species selected from the group consisting of silicon and germanium.

14. The boule of claim 13, wherein the silicon dopant species is derived from silane.

15. The boule of claim 13, wherein the germanium dopant species is derived from germane.

16. The boule of claim 1, doped to yield a room temperature electron concentration of from about 1E15 to about 5E19 cm⁻

3.

17. The boule of claim 1, doped to yield a room temperature electron concentration of from about 5E17 to about 1E19 cm⁻

3.

18. The boule of claim 1, of p-type.

19. The boule of claim 18, doped with a dopant species selected from the group consisting of beryllium, magnesium and zinc.

20. The boule of claim 19, doped using an organometallic source of the dopant species.

21. The boule of claim 18, doped to yield a room temperature hole concentration of from about 1E15 to about 1E19 cm⁻

3.

22. The boule of claim 18, doped to yield a room temperature hole concentration of from about 5E17 to about 1E19 cm⁻

3.

23. The boule of claim 1, doped with a dopant species selected from the group consisting of vanadium, chromium, iron, arsenic, manganese, cobalt, nickel and copper.

24. The boule of claim 23, doped using a vapor source of the dopant species.

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

26. The boule of claim 23, having a resistivity greater than 1E3 (more preferably greater than 1E6) ohm-cm.

27. The boule of claim 1, grown on a non-native seed crystal.

33. The boule of claim 1, having a surface defect density of less than 10⁶ defects cm⁻

2.

34. The boule of claim 1, having a surface defect density of less than 10⁴ defects cm⁻

2.

35. The boule of claim 1, having a diameter greater than 1 centimeter, and a length greater than 1 millimeter, which is substantially crack-free.

36. The boule of claim 1, 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.

37. The boule of claim 1, wherein the (Al, Ga, In) nitride comprises (Al,Ga,In)N.

38. The boule of claim 1, wherein the (Al, Ga, In) nitride comprises GaN.

41. The boule of claim 1 or a wafer derived therefrom, doped by diffusion at temperature greater than 600 degrees C.

42. The boule of claim 1, grown on a seed crystal produced by an optical liftoff technique.

43. The boule of claim 1, grown on a seed crystal 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.

44. A wafer derived from the boule of claim 1.

45. The wafer of claim 44, having an orientation selected from the group consisting of c-axis, a-axis, m-axis, r-axis.

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

47. The wafer of claim 44, having at least one of the N-face and (Al,Ga,In)-face of a c-axis-oriented wafer prepared for epitaxial growth.

48. The wafer of claim 44, wherein the boule has been grown from a native seed crystal.

49. The wafer of claim 48, parted from the native seed crystal by other than slicing or cutting.

110. A microelectronic device structure comprising a substrate derived from a boule as in claim 1, and having a device fabricated on and/or in the substrate.

111. The microelectronic device structure of claim 110, wherein the device is selected from the group consisting of light emitting diodes and lasers.

112. The microelectronic device structure of claim 110, wherein the substrate has been cleaved.

113. The microelectronic device structure of claim 112, on free-standing material.

28. A (Al, Ga, In) N boule comprising seed material and boule material grown thereon, with an interlayer between said seed material and said boule material.

29. The boule of claim 28, wherein the interlayer material has a functional character of at least one of:

alleviating or accomodating strain in the wafer source material, altering electrical characteristics of the wafer source material, reducing defect density of the wafer source material, facilitating separation of the wafer source material from the seed material, and facilitating growth nucleation of the wafer source material.

30. The boule of claim 28, wherein the interlayer is deposited by a deposition process selected from the group consisting of VPE, CVD, PVD, MBE, MOVPE, and HVPE.

31. The boule of claim 28, wherein the interlayer is formed by modifying, etching or patterning the seed crystal.

32. The boule of claim 28, wherein the interlayer is composed on one or multiple layers or materials.

39. A (Al,Ga,In) nitride boule or wafer, doped by nuclear transmutation doping.

40. The boule or wafer of claim 39, doped to yield a room temperature electron concentration of from 1E15 to 5E19 cm³.

50. A wafer parted from a boule including sequential wafer material and parting material layers, wherein the parting material is more highly absorptive of a selected radiation than is the wafer material, and wherein the wafer has been parted from the boule by impingement of said selected radiation on said parting material.

51. A device-quality (Al,Ga,In) N wafer.

52. The wafer of claim 51, having a surface with an RMS roughness less than 5 Angstroms over a 10×

10 micrometers² area.

53. The wafer of claim 51, having a radius of curvature greater than 1 meter.

54. The wafer of claim 51, having a flat oriented to better than ±

0.3 degrees.

55. The wafer of claim 51, having a flat produced by cleaving.

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

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

58. The wafer of claim 51, having a warp of less than 50 micrometers.

59. The wafer of claim 51, having a warp of less than 10 micrometers.

60. The wafer of claim 51, further comprising a microelectronic device structure therein or thereon.

61. The wafer of claim 51, 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.