Semi-insulating group III metal nitride and method of manufacture

• US 8,878,230 B2
• Filed: 03/04/2011
• Issued: 11/04/2014
• Est. Priority Date: 03/11/2010
• Status: Active Grant

• Current Assignee: SL Technology Incorporated (Reliv' International, Inc.)
• Original Assignee: Soraa, Inc.
• Inventors: D'Evelyn, Mark P.
• Primary Examiner(s): Nadav, Ori
• Application Number:
  US13/041,199
• Publication Number:
  US 20110220912A1
• Time in Patent Office: 1,341 Days
• Field of Search: 257/76, 257/79, 257/101, 257/102, 257/627
• US Class Current: 257/102
• CPC Class Codes: C30B 29/406 Gallium nitride
• CPC Class Codes: C30B 7/105 using ammonia as solvent, i.e. ammonothermal processes
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/02573 Conductivity type
• CPC Class Codes: H01L 21/02581 Transition metal or rare earth elements
• CPC Class Codes: H01L 21/02667 Crystallisation or recrystallisation of non-monocrystalline semiconductor materials, e.g. regrowth
• CPC Class Codes: H01L 21/3221 of silicon bodies, e.g. for gettering
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

A large-area, high-purity, low-cost single crystal semi-insulating gallium nitride that is useful as substrates for fabricating GaN devices for electronic and/or optoelectronic applications is provided. The gallium nitride is formed by doping gallium nitride material during ammonothermal growth with a deep acceptor dopant species, e.g., Mn, Fe, Co, Ni, Cu, etc., to compensate donor species in the gallium nitride, and impart semi-insulating character to the gallium nitride.

Claims

1. A bulk gallium-containing nitride crystal comprising:

a length greater than about 5 millimeters;

a wurtzite crystal structure;

a concentration of oxygen from about 10¹⁰ atoms per cubic centimeter to about 10¹⁷ atoms per cubic centimeter;

an impurity concentration greater than about 10¹⁵ cm<sup>−

3</sup> of at least one of Li, Na, K, Rb, Cs, Ca, F, and Cl;

a compensatory dopant selected from V, Cr, Mo, W, Mn, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Hg, and a combination of any of the foregoing, wherein the concentration of the compensatory dopant is between about 10¹⁴ cm<sup>−

3</sup> and about 10¹⁶ cm<sup>−

3</sup>;

an optical absorption coefficient less than about 10 cm<sup>−

1</sup> at wavelengths between about 395 nm and about 460 nm; and

an electrical resistivity at room temperature greater than about 10⁷ ohm-centimeter.

2. The gallium-containing nitride crystal of claim 1, comprising an impurity concentration of oxygen less than about 10¹⁶ cm⁻

3.

3. The gallium-containing nitride crystal of claim 1, comprising an impurity concentration of oxygen less than about 10¹⁵ cm⁻

3.

4. The gallium-containing nitride crystal of claim 1, wherein the concentration of the compensatory dopants is less than about 10¹⁶ cm⁻

3.

5. The gallium-containing nitride crystal of claim 1, wherein the optical absorption coefficient at wavelengths between about 395 nm and about 460 nm is less than about 2 cm⁻

1.

6. The gallium-containing nitride crystal of claim 1, wherein the optical absorption coefficient at wavelengths between about 395 nm and about 460 nm is less than about 0.2 cm⁻

1.

7. The gallium-containing nitride crystal of claim 1, wherein the gallium-containing nitride crystal has a thickness of greater than about 1 millimeter.

8. The gallium-containing nitride crystal of claim 7, wherein the length is greater than about 20 millimeters.

9. The gallium-containing nitride crystal of claim 1, wherein the length is greater than about 100 millimeters.

10. The gallium-containing nitride crystal of claim 1, wherein the crystal is characterized by a crystallographic radius curvature of greater than 100 meters.

11. The gallium-containing nitride crystal of claim 1, comprising a large-area surface characterized by-a root-mean-square surface roughness of 1 nanometer and less.

12. The gallium-containing nitride crystal of claim 11, wherein the large-area surface has a crystallographic orientation within about 5 degrees of (0 0 0 ±

1) c-plane.

13. The gallium-containing nitride crystal of claim 11, wherein the large-area surface has a crystallographic orientation within about 5 degrees of (1 0 −

1

     0) m-plane.

14. A device comprising the gallium-containing nitride crystal of claim 1, wherein the device is selected from a light emitting diode, a laser diode, a photodetector, an avalanche photodiode, a transistor, a rectifier, a thyristor;

a transistor, a rectifier, a Schottky rectifier, a thyristor, a p-i-n diode, a metal-semiconductor-metal diode, high-electron mobility transistor, a metal semiconductor field effect transistor, a metal oxide field effect transistor, a power metal oxide semiconductor field effect transistor, a power metal insulator semiconductor field effect transistor, a bipolar junction transistor, a metal insulator field effect transistor, a heterojunction bipolar transistor, a power insulated gate bipolar transistor, a power vertical junction field effect transistor, a cascode switch, an inner sub-band emitter, a quantum well infrared photodetector, a quantum dot infrared photodetector, a solar cell, and a diode for photoelectrochemical water splitting and hydrogen generation.

15. The gallium-containing nitride crystal of claim 1, wherein the electrical resistivity at room temperature is greater than about 10⁹ ohm-centimeter.

16. The gallium-containing nitride crystal of claim 1, wherein the electrical resistivity at room temperature is greater than about 10¹¹ ohm-centimeter.

17. The gallium-containing nitride crystal of claim 1, comprising an oxygen content as a substitutional impurity less than about 10 parts per million.

18. The gallium-containing nitride crystal of claim 1, comprising an oxygen content as a substitutional impurity less than about 1 parts per million.

19. The gallium-containing nitride crystal of claim 1, wherein the gallium-containing nitride crystal is semi-insulating.

20. The gallium-containing nitride crystal of claim 1, wherein the room temperature resistivity is from 10⁷ ohm-centimeters to 10¹² ohm-centimeters.

21. The gallium-containing nitride crystal of claim 1, wherein the crystal is free-standing.

22. A bulk gallium-containing nitride crystal, comprising:

a wurtzite structure;

an impurity concentration greater than about 10¹⁵ cm<sup>−

3</sup> of at least one of Li, Na, K, Rb, Cs, Ca, F, and Cl;

a concentration of oxygen from about 10¹⁰ atoms per cubic centimeter to about 10¹⁷ atoms per cubic centimeter;

a compensatory dopant selected from V, Cr, Mo, W, Mn, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Hg, and a combination of any of the foregoing, wherein the concentration of the compensatory dopant is between about 10¹⁴ cm<sup>−

3</sup> and about 10¹⁶ cm<sup>−

3</sup>;

an optical absorption coefficient less than about 2 cm<sup>−

1</sup> at wavelengths between about 395 nm and about 460 nm; and

an electrical resistivity at room temperature greater than about 10⁷ ohm-centimeter.