Annealing of an AlN buffer layer in N2-CO for growth of a high-quality AlN film on sapphire

• Published in: Applied physics express 2016-01, Vol.9 (2)
• Main Authors: Miyake, Hideto, Nishio, Gou, Suzuki, Shuhei, Hiramatsu, Kazumasa, Fukuyama, Hiroyuki, Kaur, Jesbains, Kuwano, Noriyuki
• Format: Article
• Language: English
• ISSN: 1882-0778; 1882-0786
• DOI: 10.7567/APEX.9.025501

The annealing of an AlN buffer layer in a carbon-saturated N2-CO gas on a sapphire substrate was investigated. The crystal quality of the buffer layer was significantly improved by annealing at 1650-1700 °C. An AlN buffer layer with a thickness of 300 nm was grown by metalorganic vapor phase epitaxy (MOVPE), and was annealed at 1700 °C for 1 h. We fabricated a 2-µm-thick AlN layer on the annealed AlN buffer layer by MOVPE. The full widths at half maximum of the (0002)- and ()-plane X-ray rocking curves were 16 and 154 arcsec, respectively, and the threading dislocation density was 4.7 × 108 cm−2.