Group III nitride semiconductor crystal, production method thereof and group III nitride semiconductor epitaxial wafer

• US 20050227453A1
• Filed: 02/14/2003
• Published: 10/13/2005
• Est. Priority Date: 02/15/2002
• Status: Active Grant

• Current Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Original Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Inventors: Miki, Hisayuki, Sakurai, Tetsuo, Okuyama, Mineo
• Granted Patent: US 8,236,103 B2
• Time in Patent Office: Days
• US Class Current: 438/438
• 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 25/14 Feed and outlet means for the gases; Modifying the flow of the reactive gases
• CPC Class Codes: C30B 29/403 AIII-nitrides
• CPC Class Codes: C30B 29/406 Gallium nitride
• CPC Class Codes: H01L 21/0242 Crystalline insulating materials
• 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 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/42 Transparent materials

Abstract

A method for producing a Group III nitride semiconductor crystal includes a first step of supplying a Group III raw material and a Group V raw material at a V/III ratio of 0 to 1,000 to form and grow a Group III nitride semiconductor on a heated substrate and a second step of vapor-phase-growing a Group III nitride semiconductor crystal on the substrate using a Group III raw material and a nitrogen raw material.

Claims

1. A method for producing a Group III nitride semiconductor crystal, comprising a first step of supplying a Group III raw material and a Group V raw material at a V/III ratio of 0 to 1,000 to form and grow a Group III nitride semiconductor on a heated substrate and a second step of vapor-phase-growing a Group III nitride semiconductor crystal on the substrate using a Group III raw material and a nitrogen raw material.

2. The method according to claim 1, wherein the substrate is a sapphire (Al₂O₃) substrate.

3. The method according to claim 1, wherein the Group III raw material supplied in the first step contains at least Al.

4. The method according to claim 1, wherein the Group III nitride semiconductor crystal vapor-phase-grown on the substrate in the second step comprises GaN.

5. The method according to claim 1, wherein in at least one of the first step and the second step, the growth is performed by the metal-organic chemical vapor deposition (MOCVD) method.

6. The method according to claim 1, wherein the nitrogen raw material used in the second step is ammonia (NH₃).

7. The method according to claim 1, wherein the Group III nitride semiconductor formed in the first step is an island like crystal grain.

8. The method according to claim 1, wherein the Group III nitride semiconductor formed in the first step is a columnar crystal.

9. The method according to claim 8, wherein the columnar crystal is attached onto the substrate such that a side surface of the columnar crystal stands approximately perpendicular to a surface of the substrate.

12. A Group III nitride semiconductor crystal produced by the method according to claim 1.

13. A Group III nitride semiconductor epitaxial wafer having a Group III nitride semiconductor crystal layer formed on the Group III nitride semiconductor crystal according to claim 12.

10. A method for producing a Group III nitride semiconductor crystal, comprising producing a first Group III nitride semiconductor on a heated substrate and producing a second Group III nitride semiconductor crystal on the first Group III nitride semiconductor, wherein the first Group III nitride semiconductor is an aggregate of columnar crystals or island-like crystals.

11. The method according to claim 10, wherein the columnar crystals are attached onto the substrate such that each side surface of the columnar crystals stands approximately perpendicular to a surface of the substrate.