Defect Mediated Thin-Film Growth

本研究探讨了与缺陷相互作用在决定金属薄膜生长模式中的作用有关的问题。目标是学习如何操纵生长参数，使逐层生长成为动力学上首选的生长模式。生长模式的机制检查使用结合实验，模拟和理论的方法。为了在原子水平上观察生长模式转变的细节，电沉积实验使用原位扫描隧道显微镜进行。研究的金属对金属异质外延系统包括银/金、铜/金和银/铜。这些系统允许在生长模式转变中确定错配的作用。通过对电沉积系统的改进，将逐层生长模式扩展为多层生长模式。利用嵌入原子法进行了蒙特卡罗模拟，以确定缺陷相互作用对原子簇扩散系数的影响。这项研究具有重要的材料意义，因为许多重要的工程应用都需要逐层生长模式。＊＊＊

9510663 Sieradzki This research examines issues related to the role of defect interactions in determining thin metal film growth modes. The objective is to learn how to manipulate growth parameters such that layer-by-layer growth becomes the kinetically preferred growth mode. Growth mode mechanisms are examined using combined experimental, simulation, and theoretical approaches. Electrodeposition experiments are performed using in situ scanning tunneling microscopy in order to observe the details of the growth mode transition at the atomic level. Metal-on-metal heteroepitaxial systems studied include silver/gold, copper/gold, and silver/copper. These systems permit a determination of the role of misfit in the growth mode transition. The layer-by-layer growth mode is extended into the multilayer regime by employing modifications of the electrodeposition system. Monte Carlo simulations using Embedded Atom Method potentials are performed to determine the effects of defect interactions on adatom cluster diffusivities. %%% This research has important materials implications since the layer-by-layer growth mode is desired for many important engineering applications. ***