Group III nitride crystal substrates and group III nitride crystal

• US 9,368,568 B2
• Filed: 08/27/2014
• Issued: 06/14/2016
• Est. Priority Date: 06/29/2009
• Status: Active Grant

• Current Assignee: Mitsubishi Chemical Corporation (Mitsubishi Chemical Group Corp.)
• Original Assignee: Sumitomo Electric Industries Limited (Sumitomo Corporation)
• Inventors: Uematsu, Koji, Osada, Hideki, Nakahata, Seiji, Fujiwara, Shinsuke
• Primary Examiner(s): Hossain, Moazzam
• Application Number:
  US14/470,903
• Publication Number:
  US 20140369920A1
• Time in Patent Office: 657 Days
• Field of Search: 257/E21.599, 438/460, 423/409
• US Class Current: 1/1
• CPC Class Codes: C01B 21/0632 with gallium, indium or thallium
• CPC Class Codes: C01P 2002/90 Other crystal-structural characteristics not specified above
• CPC Class Codes: C01P 2006/12 Surface area
• CPC Class Codes: C30B 29/403 AIII-nitrides
• CPC Class Codes: C30B 29/406 Gallium nitride
• CPC Class Codes: C30B 33/06 Joining of crystals
• CPC Class Codes: H01L 21/02389 Nitrides
• CPC Class Codes: H01L 21/0243 Surface structure
• CPC Class Codes: H01L 21/02433 Crystal orientation
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/02609 Crystal orientation
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 21/02658 Pretreatments cleaning in general H01L21/02041
• CPC Class Codes: H01L 29/045 by their particular orientation of crystalline planes
• CPC Class Codes: H01L 33/16 with a particular crystal structure or orientation, e.g. polycrystalline, amorphous or porous
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

Group III nitride crystal produced by cutting, from III nitride bulk crystal, a plurality of Group III nitride crystal substrates with major-surface plane orientation misoriented five degrees or less with respect to a crystal-geometrically equivalent plane orientation selected from the group consisting of {20-21}, {20-2-1}, {22-41}, and {22-4-1}, transversely arranging the substrates adjacent to each other such that their major surfaces are parallel to each other and such that their [0001] directions coincide with each other, and growing a Group III nitride crystal on the major surfaces. The Group III nitride crystal substrates are further characterized by satisfying at least either an oxygen-atom concentration of 1×10¹⁶ cm⁻³ to 4×10¹⁹ cm⁻³ or a silicon-atom concentration of 6×10¹⁴ cm⁻³ to 5×10¹⁸ cm⁻³, and by having a carrier concentration of 1×10¹⁶ cm⁻³ to 6×10¹⁹ cm⁻³.

Claims

1. A Group III nitride crystal substrate having a major surface with plane orientation being any one of [20-21], ([20-2-1], [22-41], and [22-4-1], the Group III nitride crystal substrate further characterized by:

satisfying at least one of either

an oxygen-atom concentration of between 5×

10¹⁶ cm<sup>−

3</sup> and 1×

10¹⁹ cm<sup>−

3</sup> inclusive, and

a silicon-atom concentration of between 6×

10¹⁴ cm<sup>−

3</sup> and 5×

10¹⁸ cm<sup>−

3</sup> inclusive;

having a carrier concentration of between (1×

10¹⁶ cm<sup>−

3</sup>) and (6×

10¹⁹ cm<sup>−

3</sup>) inclusive; and

in a cross-section through the crystal substrate perpendicular to either the <

1-210>

direction or to the <

10-10>

direction, an in-plane density of planar defects of from not fewer than 0.3 cm<sup>−

1</sup> to not more than 51 cm<sup>−

1</sup>.

2. A Group III nitride crystal substrate as recited in claim 1, being of at least 10 cm² area.

3. A Group III nitride crystal substrate as recited in claim 1, being of at least 40 cm² area.