Department of Physics, Purdue University, West Lafayette, Indiana 47907, USA.
Nano Lett. 2013 Jun 12;13(6):2786-91. doi: 10.1021/nl4010332.
Semiconducting nanowires have attracted lots of attention because of their potential applications. Compared with free-standing nanowires, self-aligned planar nanowires grown epitaxially on the substrate have shown advantageous properties such as being twin defect free and ready for device fabrication, opening potentials for the large-scale device applications. Understanding of planar nanowire growth, which is essential for selective growth of planar vs free-standing wires, is still limited. In this paper, we reported different growth behaviors for self-aligned planar and free-standing InAs nanowires under identical growth conditions. We present a new model based on a revised Gibbs–Thomson equation for the planar nanowires. Using this model, we predicted and successfully confirmed through experiments that higher arsenic vapor partial pressure promoted free-standing InAs nanowire growth. A smaller critical diameter for planar nanowire growth was predicted and achieved experimentally. Successful control and understanding of planar and free-standing nanowire growth established in our work opens up the potential of large-scale integration of self-aligned nanowires for practical device applications.
半导体纳米线由于其潜在的应用而引起了广泛关注。与独立纳米线相比，在衬底上外延生长的自对准平面纳米线具有无孪晶缺陷和适合器件制造等优势，为大规模器件应用开辟了潜力。对于选择性生长平面纳米线与独立纳米线的平面纳米线生长的理解仍然有限。在本文中，我们在相同的生长条件下报道了自对准平面和独立的 InAs 纳米线的不同生长行为。我们提出了一个基于修正的 Gibbs–Thomson 方程的新模型，用于平面纳米线。使用该模型，我们预测并通过实验成功证实，较高的砷蒸气分压有利于独立的 InAs 纳米线生长。我们预测并通过实验实现了较小的平面纳米线生长临界直径。我们工作中成功地控制和理解了平面纳米线和独立纳米线的生长，为自对准纳米线的大规模集成应用于实际器件打开了潜力。
