Heteroepitaxy of N-polar AlN on C-face 4H-SiC: Structural and optical properties
Heteroepitaxy of N-polar AlN on C-face 4H-SiC: Structural and optical properties
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DOI：
10.1063/5.0168970
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发表时间：
2023-12
期刊：
影响因子：
6.1
通讯作者：
Mingtao Hu;Ping Wang;Ding Wang;Yuanpeng Wu;Shubham Mondal;Danhao Wang;E. Ahmadi;Tao Ma;Zetian Mi
中科院分区：
文献类型：
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作者：
Mingtao Hu;Ping Wang;Ding Wang;Yuanpeng Wu;Shubham Mondal;Danhao Wang;E. Ahmadi;Tao Ma;Zetian Mi
迄今为止，实现N极性AlN仍然具有挑战性，这对于高功率，高频和高温电子器件，声学谐振器和滤波器，紫外（UV）光电子学和集成光子学非常重要。在这里，我们进行了详细的研究，分子束外延N-极性氮化铝的C面4 H-SiC衬底和表征。在优化条件下生长的N-极性AlN薄膜具有原子级光滑的表面和强的激子发射，在室温下的深紫外发光效率超过50%。详细的扫描透射电子显微镜（STEM）的研究表明，大多数位错终止/湮灭在200 nm的AlN直接生长在SiC衬底上，由于AlN和SiC之间的晶格失配相对较小（1%）。通过STEM和显微拉曼光谱进一步分析了AlN的应变分布，并阐明了其对温度依赖的深紫外发射的影响。
To date, it has remained challenging to achieve N-polar AlN, which is of great importance for high power, high frequency, and high temperature electronics, acoustic resonators and filters, ultraviolet (UV) optoelectronics, and integrated photonics. Here, we performed a detailed study of the molecular beam epitaxy and characterization of N-polar AlN on C-face 4H-SiC substrates. The N-polar AlN films grown under optimized conditions exhibit an atomically smooth surface and strong excitonic emission in the deep UV with luminescence efficiency exceeding 50% at room temperature. Detailed scanning transmission electron microscopy (STEM) studies suggest that most dislocations are terminated/annihilated within ∼200 nm AlN grown directly on the SiC substrate due to the relatively small (1%) lattice mismatch between AlN and SiC. The strain distribution of AlN is further analyzed by STEM and micro-Raman spectroscopy, and its impact on the temperature-dependent deep UV emission is elucidated.