Method of growing group III nitride crystals

• US 10,316,431 B2
• Filed: 10/20/2015
• Issued: 06/11/2019
• Est. Priority Date: 04/07/2006
• Status: Active Grant

• Current Assignee: Seoul Semiconductor Co., Ltd.
• Original Assignee: Seoul Semiconductor Co., Ltd., SixPoint Materials, Inc.
• Inventors: Hashimoto, Tadao, Letts, Edward, Hoff, Sierra
• Primary Examiner(s): Langman, Jonathan C
• Application Number:
  US14/918,474
• Publication Number:
  US 20160040318A1
• Time in Patent Office: 1,330 Days
• CPC Class Codes: B28D 5/045 by cutting with wires or closed-loop blades B28D5/042 takes precedence
• 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 29/64 Flat crystals, e.g. plates, strips or discs
• CPC Class Codes: C30B 33/06 Joining of crystals
• CPC Class Codes: C30B 7/10 by application of pressure, e.g. hydrothermal processes
• CPC Class Codes: C30B 7/105 using ammonia as solvent, i.e. ammonothermal processes
• CPC Class Codes: H01L 21/02389 Nitrides
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/02628 using solutions
• 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 29/32 the imperfections being within the semiconductor body
• CPC Class Codes: Y10S 117/902 Specified orientation, shape, crystallography, or size of seed or substrate
• CPC Class Codes: Y10T 428/192 Sheets or webs coplanar

Abstract

The present invention provides a method of growing an ingot of group III nitride. Group III nitride crystals such as GaN are grown by the ammonothermal method on both sides of a seed to form an ingot and the ingot is sliced into wafers. The wafer including the first-generation seed is sliced thicker than the other wafers so that the wafer including the first-generation seed does not break. The wafer including the first-generation seed crystal can be used as a seed for the next ammonothermal growth.

Claims

1. A group III nitride seed having a first uncracked surface and a second uncracked surface comprising a first layer of group III nitride wafers, the first layer having a first face and a second face, and a second layer of group III nitride wafers, the second layer having a first face and a second face, the first face of the first layer facing the first face of the second layer, the second face of the first layer having at least one crack, and overlying the second face of the first layer a sufficient thickness of group III nitride to provide said first uncracked surface.

2. A group III nitride seed according to claim 1 wherein the second face of the second layer has at least one crack, and overlying the second face of the second layer is a sufficient thickness of the group III nitride to provide the second uncracked surface of the group III nitride seed.

3. A group III nitride seed according to claim 2, wherein the wafers of the first layer are c-plane wafers and the wafers of the second layer are c-plane wafers, each having misorientation within +/−

10 degrees.

4. A group III nitride seed according to claim 3, wherein the first uncracked surface and the second uncracked surface are each nitrogen polar surfaces.

5. A group III nitride seed according to claim 2, wherein the first uncracked surface and the second uncracked surface are each nitrogen polar surfaces.

6. A group III nitride seed according to claim 1, wherein the wafers of the first layer are c-plane wafers and the wafers of the second layer are c-plane wafers, each having misorientation within +/−

10 degrees.

7. A group III nitride seed according to claim 6, wherein the first uncracked surface and the second uncracked surface are each nitrogen polar surfaces.

8. A group III nitride seed according to claim 1, wherein the first uncracked surface and the second uncracked surface are each nitrogen polar surfaces.

9. A group III nitride seed according to claim 1 wherein the second face of the first layer and the second face of the second layer are each nitrogen polar faces.

10. An ingot of crystalline group III nitride having the formula Ga_xAl_yIn_1-x-yN (0≤

x≤

1, 0≤

x+y≤

1) and having a first side with a first face and a second side with a second face, the first face having a crystalline structure polarity and the second face also having said crystalline structure polarity, wherein said ingot contains the seed of claim 1 within the ingot.

11. An ingot according to claim 10 wherein the first face has nitride polarity and the second face has nitride polarity.

12. An ingot according to claim 10 wherein the first face has group III element polarity and the second face has group III element polarity.

13. A set of pieces cut from the ingot of claim 10, wherein said set comprises a first piece cut from the first side, a second piece cut from the second side, and a third piece that contains said seed, wherein the third piece has a thickness greater than a thickness of the first piece, and wherein the thickness of the third piece is greater than a thickness of the second piece.

14. An ingot of crystalline group III nitride having the formula Ga_xAl_yIn_1-x-yN (0≤

x≤

1, 0≤

x+y≤

1) and having a first side with a first face and a second side with a second face, the first face having a crystalline structure polarity and the second face also having said crystalline structure polarity, wherein said ingot contains the seed of claim 1 within the ingot, and wherein the group III nitride wafers of the first and second layers were formed using vapor phase epitaxy.

15. An ingot according to claim 14 wherein the first face has nitride polarity and the second face has nitride polarity.

16. An ingot according to claim 14 wherein the first face has group III element polarity and the second face has group III element polarity.

17. A set of pieces cut from the ingot of claim 14, wherein said set comprises a first piece cut from the first side, a second piece cut from the second side, and a third piece that contains said seed, wherein the third piece has a thickness greater than a thickness of the first piece, and wherein the thickness of the third piece is greater than a thickness of the second piece.