Department of Physics, Colorado State University, Fort Collins, Colorado 80523, USA.
Phys Rev E. 2016 Apr;93:040802. doi: 10.1103/PhysRevE.93.040802. Epub 2016 Apr 25.
Bombardment of a solid surface with a broad, obliquely incident ion beam frequently produces nanoscale surface ripples. The primary obstacle that prevents the adoption of ion bombardment as a nanofabrication tool is the high density of defects in the patterns that are typically formed. Our simulations indicate that ion bombardment can produce nearly defect-free ripples on the surface of an elemental solid if the sample is concurrently and periodically rocked about an axis orthogonal to the surface normal and the incident beam direction. We also investigate the conditions necessary for rocking to produce highly ordered ripples and discuss how the results of our simulations can be reproduced experimentally. Finally, our simulations show that periodic temporal oscillations of coefficients in the Kuramoto-Sivashinsky equation can suppress spatiotemporal chaos and lead to patterns with a high degree of order.
用宽角度倾斜入射的离子束轰击固体表面通常会产生纳米级的表面波纹。阻碍离子束成为纳米制造工具的主要障碍是通常形成的图案中存在高密度的缺陷。我们的模拟表明，如果样品同时沿垂直于表面法线和入射光束方向的轴周期性地晃动，离子束可以在元素固体表面上产生几乎无缺陷的波纹。我们还研究了晃动产生高度有序波纹的必要条件，并讨论了如何在实验中再现我们的模拟结果。最后，我们的模拟表明，Kuramoto-Sivashinsky 方程中的系数的周期性时间振荡可以抑制时空混沌，并导致具有高度有序性的图案。
