Large area, low-defect gallium-containing nitride crystals, method of making, and method of use

• US 10,301,745 B2
• Filed: 08/02/2016
• Issued: 05/28/2019
• Est. Priority Date: 07/07/2008
• Status: Active Grant

• Current Assignee: SL Technology Incorporated (Reliv' International, Inc.)
• Original Assignee: SL Technology Incorporated (Reliv' International, Inc.)
• Inventors: D'Evelyn, Mark P., Ehrentraut, Dirk, Jiang, Wenkan, Downey, Bradley C.
• Primary Examiner(s): Song, Matthew J
• Application Number:
  US15/226,552
• Publication Number:
  US 20170029978A1
• Time in Patent Office: 1,029 Days
• CPC Class Codes: C30B 25/02 Epitaxial-layer growth
• CPC Class Codes: C30B 25/18 characterised by the substrate
• CPC Class Codes: C30B 25/20 the substrate being of the same materials as the epitaxial layer
• CPC Class Codes: C30B 29/403 AIII-nitrides
• CPC Class Codes: C30B 29/406 Gallium nitride
• CPC Class Codes: C30B 33/00 After-treatment of single crystals or homogeneous polycrystalline material with defined structure C30B31/00 takes precedence
• CPC Class Codes: C30B 33/06 Joining of crystals
• CPC Class Codes: C30B 7/105 using ammonia as solvent, i.e. ammonothermal processes
• CPC Class Codes: H01L 29/045 by their particular orientation of crystalline planes
• CPC Class Codes: H01L 29/2003 Nitride compounds
• CPC Class Codes: H01L 31/03044 comprising a nitride compounds, e.g. GaN
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01S 2304/00 Special growth methods for semiconductor lasers
• CPC Class Codes: H01S 5/32341 blue laser based on GaN or GaP
• CPC Class Codes: Y02E 10/544 Solar cells from Group III-V materials
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 428/24355 Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]

Abstract

An ultralow defect gallium-containing nitride crystal and methods of making ultralow defect gallium-containing nitride crystals are disclosed. The crystals are useful as substrates for light emitting diodes, laser diodes, transistors, photodetectors, solar cells, and photoelectrochemical water splitting for hydrogen generators.

Claims

1. A method for forming an ultralow-defect gallium-containing nitride crystal derived from a proto-seed comprising a gallium-containing nitride crystal with a length and a first thickness substantially orthogonal to a first direction of the length and a second thickness orthogonal to the first direction of the length, the ultralow-defect gallium-containing nitride crystal being characterized by a dislocation density below about 10⁵ cm⁻

2 and a stacking fault concentration below about 10² cm<sup>−

1</sup> the method comprising;

subjecting the proto-seed to an ammonothermal growth of a gallium based crystalline material to cause the proto-seed to grow in a second direction lateral to the first direction of the length to form a laterally-grown sector comprising at least one of an a-wing, a +c sector, a −

c sector, an m-m′

sector, and an m′

-m′

sector;

wherein if the laterally-grown sector comprises an a-wing,

separating the a-wing from a portion of the ultralow-defect gallium-containing nitride crystal comprising the proto-seed by slicing substantially parallel to an a-plane, and

removing residual defective material from the a-wing by removing material from a −

c-surface positioned opposite to a +c-surface of the a-wing or from a +c-surface positioned opposite to a −

c-surface of the a-wing to form said ultralow-defect gallium-containing nitride crystal;

wherein if the laterally-grown sector comprises at least one of a +c sector or a −

c sector,

separating the ±

c sector from a portion of the ultralow-defect gallium-containing nitride crystal comprising the proto-seed by slicing substantially parallel to a c-plane;

removing residual defective material from the ±

c sector by removing material substantially parallel to a c axis or by removing material substantially parallel to an m-plane to form said ultralow-defect gallium-containing nitride crystal; and

wherein if the laterally-grown sector comprises at least one of an m-m′

sector and an m′

-m′

sector,

separating an m/a wing from a portion of the ultralow-defect gallium-containing nitride crystal comprising the proto-seed by slicing substantially parallel to an a-plane; and

removing residual defective material from the m/a wing by removing material along a plane that is substantially perpendicular to an m-plane to form said ultralow-defect gallium-containing nitride crystal.

2. The method of claim 1, wherein removing comprises at least one of sawing, laser-cutting, slicing, cleaving, lapping, polishing, grinding, or chemical-mechanical polishing.

3. The method of claim 1, wherein if the laterally-grown sector comprises at least one of a +c sector or a −

c sector, further comprising removing at least one of a {10-1-1} region and a {10-11} region from the ±

c sector.

4. The method of claim 1, wherein said length is at least 5 mm and each of the first thickness and the second thickness being at least 0.1 mm.

5. The method of claim 4, wherein the ultralow-defect gallium-containing nitride crystal has a maximum dimension greater than about 5 millimeters and a minimum dimension greater than about 0.1 millimeter.

6. The method of claim 1, wherein said ultralow-defect gallium-containing nitride crystal having at least one surface characterized by a dislocation density below about 10⁴ cm⁻

2 and a stacking fault concentration below about 10 cm<sup>−

1</sup>, and wherein said residual defective material contains a higher concentration of threading dislocations and/or stacking faults than the ultralow-defect gallium-containing nitride crystal.

7. The method of claim 6, wherein the ultralow-defect gallium-containing nitride crystal has a dislocation density below about 10³ cm⁻

2 and a stacking fault concentration below about 1 cm<sup>−

1</sup>.

8. The method of claim 6, wherein the ultralow-defect gallium-containing nitride crystal has impurity concentrations of oxygen (O), hydrogen (H), and at least one of fluorine (F) and chlorine (Cl) between about 1×

10¹⁶ cm<sup>−

3</sup> and 1×

10¹⁹ cm<sup>−

3</sup>, between about 1×

10¹⁶ cm<sup>−

3</sup> and 2×

10¹⁹ cm<sup>−

3</sup>, and between about 1×

10¹⁵ cm<sup>−

3</sup> and 1×

10¹⁷ cm<sup>−

3</sup>, respectively.

9. The method of claim 1, further comprising forming at least one ultralow-defect wafer from the ultralow-defect gallium-containing nitride crystal, the ultralow-defect wafer being characterized by a dislocation density below about 10⁵ cm⁻

2 and a stacking fault concentration below about 10² cm<sup>−

1</sup>.

10. The method of claim 9, further comprising:

bonding at least two ultralow-defect wafers to a handle substrate, wherein a polar misorientation angle γ

between a first ultralow-defect wafer and second ultralow-defect wafer is less than 0.5 degree and azimuthal misorientation angles α and

β

are less than 1 degree; and

growing the at least two ultralow-defect wafers to cause a coalescence into a merged crystal.

11. The method of claim 1, further comprising:

subjecting the proto-seed to an ammonothermal growth of a gallium based crystalline material to cause the proto-seed to grow in a second direction lateral to the first direction of the length by a distance of at least 5 mm to form a laterally-grown wing or sector.

12. The method of claim 1, further comprising:

using the ultralow-defect gallium-containing nitride crystal, or a wafer or portion prepared therefrom, as a seed crystal for further bulk crystal growth;

forming an enlarged, ultralow-defect gallium-containing nitride crystal; and

forming at least one ultralow-defect wafer from the enlarged, ultralow-defect gallium-containing nitride crystal.

13. The method of claim 12, wherein the enlarged, ultralow-defect gallium-containing nitride crystal is formed by ammonothermal crystal growth.

14. The method of claim 12, wherein the enlarged, ultralow-defect gallium-containing nitride crystal is formed by hydride vapor phase epitaxy.

15. The method of claim 12, further comprising:

incorporating the ultralow-defect wafer into a semiconductor structure, wherein the semiconductor structure comprises at least one Al_xIn_yGa_(1-x-y)N epitaxial layer, where 0≤

x, y, x+y≤

1, and forms a portion of a gallium-nitride-based electronic device or optoelectronic device.