Multiscale modeling of island nucleation and growth during Cu(100) homoepitaxy
Multiscale modeling of island nucleation and growth during Cu(100) homoepitaxy
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DOI：
10.1103/physrevb.73.045422
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发表时间：
2006-01-01
影响因子：
3.7
通讯作者：
Mulheran, PA
中科院分区：
文献类型：
--
作者：
Basham, M;Montalenti, F;Mulheran, PA
研究了铜/铜(100)小岛的长时间尺度动力学。使用嵌入原子方法(EAM)势和二聚体方法鞍点搜索的原子模拟为基于格子的动力学蒙特卡罗(KMC)模拟提供了路径及其随温度变化的速率。KMC利用平移对称性来识别以前访问过的站点，并重复使用原子化率。因此，模拟可以获得很长的时间尺度，以无偏的方式揭示了小岛的解离和扩散机制。我们对岛屿扩散的结果很好地再现了以前工作中计算的活化能，并提供了相关的频率前置因子。根据先前预期的机制，岛屿解离路径是合理的。我们还利用我们在平均场速率方程中的结果，预测了在铜(100)同质外延过程中临界岛尺寸随温度和气相沉积速率变化的“动力学相图”。我们预测，更高的临界岛屿尺寸(I>；2)应该在更高的温度(类似于500K以上)下以实验可及的沉积速率观察到。
The long-time scale dynamics of small Cu/Cu(100) islands are studied. Atomistic simulations using embedded atom method (EAM) potentials and the dimer method saddle point searches provide pathways and their temperature-dependent rates to lattice-based kinetic Monte Carlo (KMC) simulations. The KMC utilizes translational symmetry to identify previously visited sites and re-use the atomistic rates. As a result very long time scales are accessible to the simulation which reveals the dissociation as well as the diffusion mechanisms of the small islands in an unbiased manner. Our results for island diffusion reproduce well the activation energies calculated in previous work, and provide in addition the associated frequency prefactors. The island dissociation pathways are rationalized in terms of previously anticipated mechanisms. We also utilize our results in mean field rate equations to predict "kinetic phase diagrams" for the critical island size as a function of temperature and vapor deposition rate during Cu(100) homoepitaxy. We predict that the higher critical island sizes (i > 2) should be observable at higher temperatures (above similar to 500 K) at experimentally accessible deposition rates.