[19a-Z27-1~9] 15.4 III-V-group nitride crystals

[19a-Z27-6] Vacancy-type defects in AlN deposited by RF sputtering studied by positron annihilation

〇Akira Uedono¹, Kanako Shojiki², Kenjiro Uesugi³, Shigefusa F. Chichibu⁴, Shoji Ishibashi⁵, Marcel Dickmann⁶, Werner Egger⁶, Christoph Hugenschmidt⁷, Hideto Miyake^2,8 (1.Univ. of Tsukuba, 2.Grad. Sch. Eng. Mie Univ., 3.Str. Plan. Off. RR Mie Univ, 4.Tohoku Univ., 5.AIST, 6.UniBwM, 7.TUM, 8.Gra. Sch. RIS Mie Univ.)

Keywords:AlN, defect, positron annihilation

Positron annihilation is a useful technique for characterizing vacancy-type defects in semiconductors. In the present study, we used monoenergetic positron beams to study the annealing behaviors of vacancy-type defects in AlN films grown by using a radio frequency (RF) sputtering technique.
Vacancy-type defects in AlN films were probed by positron annihilation spectroscopy. The AlN films were deposited on sapphire substrates by using RF sputtering technique. For the sputtered AlN, the major defect species was identified to be complexes between Al-vacancy and oxygen atoms located at nitrogen sites. Vacancy clusters were introduced after annealing at 1300C in N2 atmosphere, but their concentration decreased with a higher annealing temperature. The vacancy-oxygen complexes, however, still existed in the AlN film even after annealing at 1700C.