Chemical mechanical planarization is becoming increasingly important in the fabrication of multilayer semiconductor devices. Ideally, one wants a slurry that does not etch planar metallization layers, yet does dissolve metallic fragments abraded from the device surface. This requires the planarization process to be under kinetic control, and the leaching of fragments to be under, or closer to, thermodynamic control. As a first step towards better understanding the underlying surface science, with an eventual goal of developing better polishing slurries, we are examining the chemical and electrochemical action of different complexing agents at specific pH and redox potentials. Our results are evaluated with reference to the Eh-pH diagram for the system. A different project will examine the fundamental physicochemical phenomena controlling the behavior of polishing slurries, with a view to formulating better slurries, reducing the consumption of slurries, and allowing recycle and detoxification of slurries.
Graduate Student: Serdar
Aksu