Superconformal Electrodeposition for 3‐Dimensional Interconnects

Electrodeposition is a key fabrication process used in the state‐of‐the‐art multilevel Cu metallization of microelectronic interconnects, from transistor to circuit board length scale. Recent electrochemical surface science and feature filling studies have provided mechanistic insight into the role of additives in superconformal film growth responsible for void‐free filling of recessed surface features. These studies have shown that a physical model based on mass conservation of accelerating surfactant species during area change very effectively describes feature filling of Cu, Ag, and Au from different electrolytes. This paper presents a selective and cursory review of some relevant developments underway in our laboratory.