Department of Physics, University of North Texas, Denton, TX 76203, USA.
Small. 2012 Apr 10;8(7):1066-72. doi: 10.1002/smll.201102350. Epub 2012 Feb 14.
The removal of single atomic layers from multi-layer graphene using a He plasma is reported. By applying sample biases of -60 and +60 V during He plasma exposure, layer removal is found to be due to electrons instead of He ions or neutrals in the plasma. The rate of layer removal depends on exposure time, sample bias, and pre-annealing treatments. Optical contrast microscopy and atomic force microscopy studies show that the removal of C atoms occurs approximately one layer at a time across the entire multi-layer sample with no observable production of large pits or reduction in lateral dimensions. Layer removal is proposed to arise from the electron-stimulated dissociation of C atoms from the basal plane. This process differs from plasma techniques that use reactive species to etch multi-layer graphene.
使用氦等离子体从多层石墨烯中去除单层的方法被报道。通过在氦等离子体暴露期间施加-60 和+60V 的样品偏压，发现层去除是由于电子而不是等离子体中的氦离子或中性粒子引起的。层去除的速率取决于暴露时间、样品偏压和预退火处理。光学对比显微镜和原子力显微镜研究表明，C 原子的去除是逐个单层进行的，整个多层样品上没有观察到大凹坑的产生或横向尺寸的减小。提出层去除是由于电子激发从基面解离 C 原子。这个过程与使用反应性物种刻蚀多层石墨烯的等离子体技术不同。
