III Nitride Crystal Substrate, and Light-Emitting Device and Method of Its Manufacture

• US 20090140287A1
• Filed: 11/28/2008
• Published: 06/04/2009
• Est. Priority Date: 11/30/2007
• Status: Active Grant

• Current Assignee: Sumitomo Electric Industries Limited (Sumitomo Corporation)
• Original Assignee: Sumitomo Electric Industries Limited (Sumitomo Corporation)
• Inventors: Fujiwara, Shinsuke, Yoshida, Hiroaki
• Granted Patent: US 8,546,166 B2
• Time in Patent Office: Days
• US Class Current: 257/103
• CPC Class Codes: C30B 19/02 using molten solvents, e.g. flux
• CPC Class Codes: C30B 23/02 Epitaxial-layer growth
• CPC Class Codes: C30B 25/02 Epitaxial-layer growth
• 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 21/02458 Nitrides
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 21/02625 using melted materials
• CPC Class Codes: H01L 21/02658 Pretreatments cleaning in general H01L21/02041
• CPC Class Codes: H01L 29/32 the imperfections being within the semiconductor body
• CPC Class Codes: H01L 33/0075 comprising nitride compounds
• CPC Class Codes: H01L 33/025 Physical imperfections, e.g. particular concentration or distribution of impurities

Abstract

Toward making available III nitride crystal substrates advantageously employed in light-emitting devices, and light-emitting devices incorporating the substrates and methods of manufacturing the light-emitting devices, a III nitride crystal substrate has a major face whose surface area is not less than 10 cm² and, in a major-face principal region excluding the peripheral margin of the major face from its outer periphery to a 5 mm separation from its outer periphery, the total dislocation density is from 1×10⁴ cm⁻² to 3×10⁶ cm⁻², and the ratio of screw-dislocation density to the total dislocation density is 0.5 or greater.

Claims

1. A Group-III nitride crystal substrate having a major face whose surface area is not less than 10 cm², wherein, in a major-face principal region excluding the peripheral margin of the major face from its outer periphery to a 5 mm separation from its outer periphery, the total dislocation density is between 1×

10⁴ cm<sup>−

2</sup> and 3×

10⁶ cm<sup>−

2</sup> inclusive, and the ratio of screw-dislocation density to the total dislocation density is 0.5 or greater.

2. A III-nitride crystal substrate as set forth in claim 1, wherein the ratio of the screw-dislocation density to the total dislocation density is 0.9 or greater.

3. A light-emitting device comprising:

a III-nitride crystal substrate as set forth in claim 1; and

an at least single-lamina III nitride layer formed onto the III nitride crystal substrate.

4. A light-emitting device comprising:

a III-nitride crystal substrate as set forth in claim 2; and

an at least single-lamina III nitride layer formed onto the III nitride crystal substrate.

5. A light-emitting device manufacturing method, comprising:

a step of preparing a III nitride crystal substrate as set forth in claim 1; and

a step of forming an at least single-lamina III nitride layer onto the III nitride crystal substrate.

6. A light-emitting device manufacturing method, comprising:

a step of preparing a III nitride crystal substrate as set forth in claim 2; and

a step of forming an at least single-lamina III nitride layer onto the III nitride crystal substrate.