Nitride semiconductor free-standing substrate

• US 7,649,194 B2
• Filed: 10/03/2006
• Issued: 01/19/2010
• Est. Priority Date: 06/14/2006
• Status: Active Grant

• Current Assignee: Sumitomo Chemical Company Limited
• Original Assignee: Hitachi Cable Limited (Proterial Ltd.)
• Inventors: Yoshida, Takehiro
• Primary Examiner(s): Tran; Long K
• Application Number:
  US11/541,790
• Publication Number:
  US 20070290228A1
• Time in Patent Office: 1,204 Days
• Field of Search: 257/190, 257/103, 257/13, 257/79, 257/E33.059, 257/E25.032
• US Class Current: 257/13
• CPC Class Codes: C30B 25/18 characterised by the substrate
• CPC Class Codes: C30B 29/403 AIII-nitrides
• CPC Class Codes: H01L 21/0242 Crystalline insulating materials
• CPC Class Codes: H01L 21/02491 Conductive materials
• 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 21/02639 Preparation of substrate for selective deposition
• CPC Class Codes: H01L 21/02647 Lateral overgrowth
• CPC Class Codes: H01L 33/0075 comprising nitride compounds

Abstract

A nitride semiconductor free-standing substrate formed of a free-standing nitride-based compound semiconductor crystal that has a variation in lattice constant of ±12 ppm or less.

Claims

1. A nitride semiconductor free-standing substrate, comprising:

a free-standing nitride-based compound semiconductor crystal that comprises a variation in lattice constant of ±

12 ppm or less;

wherein the variation in lattice constant comprises a variation of measured a-axis lengths.

2. The nitride semiconductor free-standing substrate according to claim 1, wherein:

the free-standing nitride-based compound semiconductor crystal comprises Al_xIn_yGa_1-x-yN (0≦

x+y≦

1).

3. The nitride semiconductor free-standing substrate according to claim 1, wherein:

the variation in lattice constant comprises a variation of measured lattice constants in a plane of a region except a part ranging 2 mm inside from an outermost circumference of the substrate in a radius direction.

4. A light emitting device, comprising:

the nitride semiconductor free-standing substrate as defined in claim 1; and

a light emitting layer comprising a nitride-based compound semiconductor and formed on the substrate.

5. A nitride semiconductor free-standing substrate, comprising:

a free-standing nitride-based compound semiconductor crystal that comprises a variation in lattice constant of ±

12 ppm or less;

wherein the free-standing nitride-based compound semiconductor crystal comprises Al_xIn_yGa_1-x-yN (0≦

x+y≦

1).

6. The nitride semiconductor free-standing substrate according to claim 5, wherein:

the variation in lattice constant comprises a variation of measured lattice constants in a plane of a region except a part ranging 2 mm inside from an outermost circumference of the substrate in a radius direction.

7. A light emitting device, comprising:

the nitride semiconductor free-standing substrate as defined in claim 6; and

a light emitting layer comprising a nitride-based compound semiconductor and formed on the substrate.