Study of Slurry Composition Transition in a Rotary Copper CMP Process

Abstract

AbstractThe polishing pad is one of the prime components in a typical Chemical Mechanical Polishing (CMP) process. The structure and transport properties of a polishing pad are critical in determining the particle and chemical utilization in a conventional CMP process. Our earlier paper investigated the particle retention and transport on two different polishing pads, IC-1400 and Suba-500, during copper polishing. In this paper, the results of chemical retention and transport of IC-1400 and Suba-500 pads during copper polishing are presented. The polish rate results from slurry-step-flow experiments with H2O2-glycine based slurries, where the concentrations of chemicals in the slurry are altered in steps during polishing, are correlated to the chemical retention and transport characteristics of these pads. It is found that IC-1400 has a higher chemical transport capability than Suba-500 pad, which is shown to affect the polish rates of copper.