Growth of free-standing wurtzite AlGaN by MBE using a highly efficient RF plasma source
Growth of free-standing wurtzite AlGaN by MBE using a highly efficient RF plasma source
复制标题
使用高效 RF 等离子体源通过 MBE 生长独立式纤锌矿 AlGaN
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
C. T. Foxon
中科院分区：
文献类型：
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作者：
S. Novikov;C. R. Staddon;J. Whale;A. Kent;C. T. Foxon
紫外光发光二极管(UV LED)目前正被开发用于各种潜在的应用，包括水净化、表面去污、光学传感和固态照明。这一发展的基础是用金属-有机气相外延(MOVPE)或分子束外延(MBE)生长的AlxGa1_xN紫外光LED的成功生产。最初的研究主要使用蓝宝石作为衬底，但这导致了外延薄膜中的高密度缺陷，现在正在使用块状GaN或AlN衬底来将其降低到可接受的值。然而，GaN和AlN的晶格参数明显不同，因此任何生长在这两种衬底上的AlGaN合金都将仍然处于应变状态。然而，如果AlGaN衬底可用，则可以避免这个问题并实现整体晶格匹配。目前，已有的体相GaN和AlN衬底是通过MOVPE和物理气相输运两种方法制备的，但这两种方法都很难制备出厚的AlGaN自支撑薄膜。作者使用等离子体辅助分子束外延生长了厚度达100 lm的自支撑AlxGa1_xN，使用了牛津应用研究所的HD25源和Riber的一种新的高效源来提供活性氮。电影是在2英寸和3英寸的屏幕上拍摄的。生长速率为0.2~3lm/h，AlN含量为0%和20%的直径蓝宝石和GaAs(111)B衬底。二次离子质谱仪研究表明，Al、Ga和N在整个薄膜中均匀掺入，并且在所有情况下都观察到了强烈的室温光致发光。对于生长在GaAs上的薄膜，作者通过使用标准的化学腐蚀剂去除GaAs，获得了独立的AlGaN衬底，以便随后通过MOVPE或MBE生长。由于AlxGa1_xN自支撑薄膜可以在一天内生长，因此使用高生长速率使其成为一种潜在的可行的商业过程，并且这种方法有可能扩展到具有合适的等离子体源的多晶片系统。
Ultraviolet light emitting diodes (UV LEDs) are now being developed for various potential applications including water purification, surface decontamination, optical sensing, and solid-state lighting. The basis for this development is the successful production of AlxGa1_xN UV LEDs grown by either metal-organic vapor phase epitaxy (MOVPE) or molecular beam epitaxy (MBE). Initial studies used mainly sapphire as the substrate, but this result in a high density of defects in the epitaxial films and now bulk GaN or AlN substrates are being used to reduce this to acceptable values. However, the lattice parameters of GaN and AlN are significantly different, so any AlGaN alloy grown on either substrate will still be strained. If, however, AlGaN substrates were available, this problem could be avoided and an overall lattice match achieved. At present, the existing bulk GaN and AlN substrates are produced by MOVPE and physical vapor transport, but thick freestanding films of AlGaN are difficult to produce by either method. The authors have used plasmaassisted MBE to grow free-standing AlxGa1_xN up to 100 lm in thickness using both an HD25source from Oxford Applied Research and a novel high efficiency source from Riber to provide active nitrogen. Films were grown on 2- and 3-in. diameter sapphire and GaAs (111)B substrates with growth rates ranging from 0.2 to 3 lm/h and with AlN contents of 0% and _20%. Secondary ion mass spectrometer studies show uniform incorporation of Al, Ga, and N throughout the films, and strong room temperature photoluminescence is observed in all cases. For films grown on GaAs, the authors obtained free-standing AlGaN substrates for subsequent growth by MOVPE or MBE by removing the GaAs using a standard chemical etchant. The use of high growth rates makes this a potentially viable commercial process since AlxGa1_xN free-standing films can be grown in a single day and potentially this method could be extended to a multiwafer system with a suitable plasma source.
影响因子：
1.8
作者：
S. Novikov;C. R. Staddon;R. E. L. Powell;A. Akimov;F. Luckert;P. Edwards;R. Martin;A. Kent;C. T. Foxon
通讯作者：
S. Novikov;C. R. Staddon;R. E. L. Powell;A. Akimov;F. Luckert;P. Edwards;R. Martin;A. Kent;C. T. Foxon