Cu contamination control for advanced interconnect manufacturing

As IC manufacturers are moving to copper metallization for their most advan ced products, contamination control presents a big challenge for the back-e nd-of-line manufacturing processes. Copper contamination could be introduce d or spread from various sources, such as copper processing tools or wafers with open copper surfaces, and might cause catastrophic effects on product ion. By looking into a generic copper damascene process flow, requirements for critical cleaning steps can be identified, especially for fabs with mix ed conventional aluminum and copper metallization.