Microscopic Dynamics of Roughening in Copper Electroplating

电镀铜用于制造微电子器件。由于其优异的导电性和可扩展性，它很有可能取代铝合金作为片上互连。电镀工艺的工程设计和控制依赖于表面活性添加剂。这个项目是对化学和分子表面过程的实验研究，这些过程决定了镀膜表面的微观性质。氯离子和溶解氧将被用作模型添加剂，这是在晶体生长过程中推广表面处理对亚微米级材料组织的影响的第一步。该项目的中心工作将是利用原位原子力显微镜对铜单晶和气相沉积种子层上的同质外延沉积在电镀过程中和开路时的动态表面性质进行定量测量和分析。关键特征的变化率将用于评估表面过程，特别是成核、放电点和表面扩散，因为它们取决于沉积参数和添加剂膜的存在。用旋转的环盘电极研究了表面化学状态及其与生长机制的关系。将开始探索性工作，以确定无机成分与有机添加剂的相互作用。

Electroplated copper is used in the fabrication of microelectronic devices. Because of its superior conductivity and scalability, it is likely to replace aluminum alloys for on-chip interconnects. The engineering design and control of plating processes rely on surface-active additives. This project is an experimental study of chemical and molecular surface processes, which determine the microscopic properties of the plated surface. Chloride ion and dissolved oxygen will be used as model additives in a first step toward generalizing the impact of surface processes on the organization of material on the sub-micron level during crystal growth. The central work of the project will be the quantitative measurement and analysis, by in-situ atomic-force microscopy, of the dynamic surface properties of homoepitaxial deposits on copper single crystals and on vapor-deposited seed layers during plating and at open circuit. The rates of change of key features will be used to evaluate surface processes, particularly nucleation, point of discharge, and surface diffusion, as they depend on deposition parameters and the presence of additive films. A rotating ring-disk electrode will be used to study the surface chemical regime and its relationship to the growth mechanisms. Exploratory work to determine the interactions of inorganic components with organic additives will be initiated.