Abstract In this study we show how to realize a self-assembled nano-patterned sapphire surface on 2 inch diameter epi-ready wafer and the subsequent AlN overgrowth both in the same metal-organic vapor phase epitaxial process. For this purpose in-situ annealing in H 2 environment was applied prior to AlN growth to thermally decompose the c-plane oriented sapphire surface. By proper AlN overgrowth management misoriented grains that start to grow on non c-plane oriented facets of the roughened sapphire surface could be overcome. We achieved crack-free, atomically flat AlN layers of 3.5 µm thickness. The layers show excellent material quality homogeneously over the whole wafer as proved by the full width at half maximum of X-ray measured ω-rocking curves of 120 arcsec to 160 arcsec for the 002 reflection and 440 arcsec to 550 arcsec for the 302 reflection. The threading dislocation density is 2 ∗ 10 9 cm −2 which shows that the annealing and overgrowth process investigated in this work leads to cost-efficient AlN templates for UV LED devices.

中文翻译：

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在热分解蓝宝石表面上生长的高质量 AlN

摘要 在这项研究中，我们展示了如何在相同的金属有机气相外延工艺中在直径为 2 英寸的外延晶片上实现自组装纳米图案蓝宝石表面和随后的 AlN 过度生长。为此目的，在 AlN 生长之前应用 H 2 环境中的原位退火以热分解 c 面取向的蓝宝石表面。通过适当的 AlN 过度生长管理，可以克服开始在粗糙蓝宝石表面的非 c 面取向小面上生长的错误取向晶粒。我们实现了 3.5 µm 厚的无裂纹、原子级平坦的 AlN 层。这些层在整个晶片上均匀地显示出优异的材料质量，这由 X 射线测量的 ω-摇摆曲线的半高全宽证明，002 反射为 120 弧秒至 160 弧秒，302 反射为 440 弧秒至 550 弧秒。穿透位错密度为 2 ∗ 10 9 cm -2 这表明本工作中研究的退火和过度生长过程导致了用于 UV LED 器件的具有成本效益的 AlN 模板。