| 摘要 |
PROBLEM TO BE SOLVED: To improve surface flatness and crystallinity of a group III nitride semiconductor.SOLUTION: A sapphire substrate 10 having a C-surface as a main surface, is prepared, and one surface is subjected to irregularities processing by dry etching according to ICP(fig.1(a)). The sapphire substrate 10 subjected to irregularities processing, is subjected to heat treatment at higher than 800°C and equal to or less than 1100°C in hydrogen or nitrogen atmosphere. A buffer layer 20 consisting of AlN, is formed on a surface of the sapphire substrate 10, on which the irregularities processing is applied, by magnetron sputtering (fig.1(b)). Then a group III nitride semiconductor layer 30 having the C-surface as the main surface, is grown to 1 to 10 μm on the buffer layer 20 by a MOCVD method (fig.1(c)). |
