Chason E, Chan W L
Brown University, Division of Engineering, Providence, RI 02192, USA.
J Phys Condens Matter. 2009 Jun 3;21(22):224016. doi: 10.1088/0953-8984/21/22/224016. Epub 2009 May 12.
Kinetic Monte Carlo simulations model the evolution of surfaces during low energy ion bombardment using atomic level mechanisms of defect formation, recombination and surface diffusion. Because the individual kinetic processes are completely determined, the resulting morphological evolution can be directly compared with continuum models based on the same mechanisms. We present results of simulations based on a curvature-dependent sputtering mechanism and diffusion of mobile surface defects. The results are compared with a continuum linear instability model based on the same physical processes. The model predictions are found to be in good agreement with the simulations for predicting the early-stage morphological evolution and the dependence on processing parameters such as the flux and temperature. This confirms that the continuum model provides a reasonable approximation of the surface evolution from multiple interacting surface defects using this model of sputtering. However, comparison with experiments indicates that there are many features of the surface evolution that do not agree with the continuum model or simulations, suggesting that additional mechanisms are required to explain the observed behavior.
动力学蒙特卡罗模拟利用缺陷形成、复合和表面扩散的原子级机制，对低能离子轰击过程中表面的演化进行建模。由于各个动力学过程是完全确定的，因此由此产生的形态演化可以直接与基于相同机制的连续介质模型进行比较。我们给出了基于曲率相关溅射机制和可移动表面缺陷扩散的模拟结果。将这些结果与基于相同物理过程的连续介质线性不稳定性模型进行了比较。发现模型预测与模拟结果在预测早期形态演化以及对诸如通量和温度等工艺参数的依赖性方面吻合良好。这证实了连续介质模型使用这种溅射模型，能对多个相互作用的表面缺陷引起的表面演化提供合理的近似。然而，与实验的比较表明，表面演化的许多特征与连续介质模型或模拟结果不一致，这表明需要额外的机制来解释观察到的行为。
