AlN growth on nano-patterned sapphire: A route for cost efficient pseudo substrates for deep UV LEDs

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• 作者：Sylvia Hagedorn ; Arne Knauer ; Anna Mogilatenko ; Eberhard Richter and Markus Weyers
• 刊名：physica status solidi (a)
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：213
• 期：12
• 页码：3178-3185
• 全文大小：1820K
• ISSN：1862-6319

文摘

C-plane-oriented sapphire substrates that were patterned on the nanoscale were overgrown by AlN using metal-organic vapor phase epitaxy. The occurrence of undesired misaligned AlN growth was detected. We found that this misaligned growth can be overcome by a proper choice of growth temperature and V/III ratio. Up to 8 μm thick c-plane-oriented AlN with a coalesced surface was obtained. An effective dislocation reduction was found due to bending of threading dislocation lines toward free surfaces during lateral growth. The distribution of crystal defects suggests that step bunching in AlN is accompanied by dislocation accumulation. Furthermore, nearly defect-free AlN crystallites with a hexagonal shape and a size of about 2 μm were observed.