[16p-Z27-1~15] 15.4 III-V-group nitride crystals

[16p-Z27-6] Discrete AlN mole fraction observed in AlGaN Layer with Dense Macrosteps (1)

〇Akira Hirano¹, Yosuke Nagasawa¹, Masamichi Ippommatsu¹, Hideki Sako², Ai Hashimoto², Ryuichi Sugie², Yoshio Honda³, Hiroshi Amano³, Isamu Akasaki⁴, Kazunobu Kojima⁵, Shigefusa Chichibu⁵ (1.UV Craftory Co., Ltd, 2.Toray Research Center Inc., 3.IMaSS, Nagoya Univ., 4.Meijo Univ., 5.IMRAM, Tohoku Univ.)

Keywords:AlGaN, DUV, LED

When n-AlGaN is grown on AlN with dense macrosteps, 20 nm-wide Ga-rich stripe zones originating from the macrosteps are formed, which are considered to function as current pathways towards the edgelines in QWs. Owing to this structure, electrons are preferentially injected to the edgelines in the QW where exhibit the high internal quantum efficiency. Thus, AlGaN-based deep ultraviolet (DUV) LEDs with this unique structure can obtain the high external quantum efficiency. In this work, method to analyze the AlGaN composition of the 20 nm-wide current pathways was demonstrated with high spatial resolution of ~ 3 nm keeping the accuracy of <2 %.