[21p-146-1~17] 15.4 III-V-group nitride crystals

[21p-146-11] AlN template using DC sputtered AlN films with high-temperature annealing

〇Yosuke Mogami^1,2, Shogo Motegi^1,2, Atsushi Osawa³, Kazuto Osaki³, Yukitake Tanioka³, Atsushi Maeoka³, Masafumi Jo¹, Noritoshi Maeda¹, Hiroyuki Yaguchi², Hideki Hirayama¹ (1.RIKEN, 2.Saitama Univ., 3.SCREEN Finetech Solutions Co.Ltd.)

Keywords:UV-LED, sputtering, AlN template

AlGaN-based UV light-emitting diodes (LEDs) have attracted much attention because of their wide-range applications in disinfection and bio-medical fields. Recently, high-temperature annealing (HTA) technique has been proposed to improve the crystalline quality of sputtered AlN on sapphire which paves the way for high-efficiency AlGaN LEDs with low cost. During the annealing, columnar AlN with small boundaries coalesced into a uniform film, reducing the crystal mosaicity. However, the recrystallization process may also produce large hillocks if AlN islands with different crystal orientation are contained in the initial sputtered film. Here, we investigate the evolution of the surface morphology and crystalline quality of sputtered AlN films in terms of the annealing temperature.