[18a-E310-1~10] 15.4 III-V-group nitride crystals

[18a-E310-8] Increased Strain Relaxation in AlGaN Layers Grown on Sputter-based AlN Templates

〇Yosuke Mogami^1,2, Atsushi Osawa³, Kazuto Ozaki³, Yukitake Tanioka³, Atsushi Maeoka³, Yuri Itokazu^1,2, Shunsuke Kuwaba^1,2, Jo Masafumi¹, Noritoshi Maeda¹, Hiroyuki Yaguchi², Hideki Hirayama¹ (1.RIKEN, 2.Saitama Univ., 3.SCREEN)

Keywords:sputter, annealing, strain

AlGaN-based deep-UV light-emitting diodes are applicable to various fields such as disinfection, water/air purification and bio-medical. Since AlGaN crystal structure is wurtzite which has a large effect of polarization due to strain, it is important to control the strain state of the active layer to improve the characteristics of the AlGaN LED. Recently, sputtering and high-temperature annealing technique has attracted much attention because it can produce a high-quality AlN layer with a relatively thin film thickness. Sputtered AlN layer with HTA is, then, a promising candidate for controlling the strain state of the AlGaN/AlN LEDs. To examined this possibility, we investigated the relaxation ratio and the curvature of the AlGaN/AlN layer as a function of the n-AlGaN layer thickness (0.5-6.0 μm) using AlN templates with different thickness (1.2 μm and 4.0 μm).