1H-Benzotriazole Incorporated Pad for Chemical Mechanical Planarization of Copper

Chemical mechanical polishing (CMP) pads are generally designed to play a passive role in terms of chemical reactions that occur on the surface to be polished. For copper CMP, a pad that is capable of initiating and controlling various chemical reactions on the copper surface can bring another dimension of flexibility to the CMP process. This work investigates such a model pad for its potential applications in copper CMP. More specifically, the physical and chemical properties of a polyurethane pad containing 1H-benzotriazole (BTA) are examined. When applied to Cu blanket wafers, the BTA-containing pad yielded a higher removal rate compared to the conventional CMP process with the reference pad. For patterned wafer polishing, the results indicate that the BTA-containing pad is effective in improving the step height reduction efficiency and in minimizing dishing and erosion. The potential applications of a pad with such a design for gaining a fundamental understanding of the copper CMP process are discussed based on these experimental results.