Comparative Spectroscopic Study of Aluminum Nitride Grown by MOCVD in H2 and N2 Reaction Environment
Comparative Spectroscopic Study of Aluminum Nitride Grown by MOCVD in H2 and N2 Reaction Environment
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DOI：
10.3390/coatings12070924
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发表时间：
2022-06
期刊：
影响因子：
3.4
通讯作者：
Samiul Hasan;M. Jewel;S. Karakalos;M. Gaevski;I. Ahmad
中科院分区：
文献类型：
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作者：
Samiul Hasan;M. Jewel;S. Karakalos;M. Gaevski;I. Ahmad
本文报道了在氢（H2）和氮（N2）气体反应环境中在蓝宝石（Al 2 O3）基片上外延生长的氮化铝（AlN）薄膜的比较光谱研究。通过金属有机化学气相沉积（MOCVD）生长类似厚度（~3.0 µm）的AlN膜以进行比较。采用高分辨X射线衍射（HR-XRD）、X射线光电子能谱（XPS）、拉曼散射（RS）、二次离子质谱（西姆斯）、阴极发光（CL）、原子力显微镜（AFM）和扫描电子显微镜（SEM）等测试手段，研究了气体环境对AlN外延层的影响。研究表明，在氮气环境中生长的AlN层具有50%的应力（~0.5 GPa）和相似的总位错密度（~109/cm 2）相比，在氢气环境中生长的薄膜。另一方面，与在N2生长环境中生长的膜相比，在H2气体环境中生长的AlN膜具有约少33%的碳和少41%的氧杂质。讨论了在蓝宝石衬底上MOCVD系统中两种不同气体环境下生长AlN外延层的结构质量和杂质掺入的可能机制。
We report a comparative spectroscopic study on the thin films of epitaxial aluminum nitride (AlN) on basal plane sapphire (Al2O3) substrates grown in hydrogen (H2) and nitrogen (N2) gas reaction environments. AlN films of similar thicknesses (~3.0 µm) were grown by metal-organic chemical vapor deposition (MOCVD) for comparison. The impact of the gas environment on the AlN epilayers was characterized using high-resolution X-ray diffraction (HR-XRD), X-ray photoelectron spectroscopy (XPS), Raman scattering (RS), secondary ion mass spectroscopy (SIMS), cathodoluminescence (CL), atomic force microscopy (AFM), and scanning electron microscopy (SEM). The study showed that AlN layers grown in a N2 environment have 50% less stress (~0.5 GPa) and similar total dislocation densities (~109/cm2) as compared to the films grown in a H2 environment. On the other hand, AlN films grown in a H2 gas environment have about 33% lesser carbon and 41% lesser oxygen impurities than films grown in a N2 growth environment. The possible mechanisms that influenced the structural quality and impurity incorporation for two different gas environments to grow AlN epilayers in the MOCVD system on sapphire substrates were discussed.