| 摘要 |
Fracture toughness of AlGaN single-crystal substrate is improved and its absorption coefficient reduced. A nitride semiconductor single-crystal substrate has a composition represented by the formula Al<SUB>x</SUB>Ga<SUB>1-x</SUB>N (0<=x<=1), and is characterized by having a fracture toughness of (1.2-0.7x) MPa.m<SUP>1/2 </SUP>or greater and a surface area of 20 cm<SUP>2</SUP>, or, if the substrate has a composition represented by the formula Al<SUB>x</SUB>Ga<SUB>1-x</SUB>N (0.5<=x<=1), by having an absorption coefficient of 50 cm<SUP>-1 </SUP>or less in a 350 to 780 nm total wavelength range.
|
