A cautious approach to the removal of Ta in the CMP polishing of Cu/Ta structures

摘要

This work examines the electrochemical behavior of Ta in a variety of electrolytes with varying pH, with and without oxidizers, complexing agents and inhibitors, as well as in actual polishing slurries. Tests are conducted under static and dynamic conditions, with and without surface abrasion. Results are utilized to evaluate the most important factors determining the rate of Ta dissolution, the applicable polishing mechanism, and the selection of a single or two-step approach in chemical mechanical polishing of Cu/Ta structures.