Langegger Rupert, Hradil Klaudia, Steiger-Thirsfeld Andreas, Bertagnolli Emmerich, Lugstein Alois
Institute for Solid State Electronics, Vienna University of Technology, Vienna, Austria.
Nanotechnology. 2014 Aug 1;25(30):305302. doi: 10.1088/0957-4484/25/30/305302. Epub 2014 Jul 10.
In this paper, we report on the surface evolution of focused ion beam treated single crystalline Bi(001) with respect to different beam incidence angles and channeling effects. 'Erosive' sputtering appears to be the dominant mechanism at room temperature (RT) and diffusion processes during sputtering seem to play only a minor role for the surface evolution of Bi. The sputtering yield of Bi(001) shows anomalous behavior when increasing the beam incidence angle along particular azimuthal angles of the specimen. The behavior of the sputtering yield could be related to channeling effects and the relevant channeling directions are identified. Dynamic annealing processes during ion irradiation retain the crystalline quality of the Bi specimen allowing ion channeling at RT. Lowering the specimen temperature to T = -188 °C reduces dynamic annealing processes and thereby disables channeling effects. Furthermore unexpected features are observed at normal beam incidence angle. Spike-like features appear during the ion beam induced erosion, whose growth directions are not determined by the ion beam but by the channeling directions of the Bi specimen.
在本文中，我们报告了聚焦离子束处理的单晶Bi(001)在不同束入射角和沟道效应下的表面演化情况。“侵蚀性”溅射似乎是室温（RT）下的主导机制，溅射过程中的扩散过程对Bi的表面演化似乎只起次要作用。当沿样品的特定方位角增加束入射角时，Bi(001)的溅射产率表现出异常行为。溅射产率的行为可能与沟道效应有关，并确定了相关的沟道方向。离子辐照过程中的动态退火过程保持了Bi样品的晶体质量，使得在室温下能够进行离子沟道效应。将样品温度降低到T = -188 °C会减少动态退火过程，从而消除沟道效应。此外，在正常束入射角下观察到了意想不到的特征。在离子束诱导的侵蚀过程中出现了尖峰状特征，其生长方向不是由离子束决定的，而是由Bi样品的沟道方向决定的。
