Paper Title
Effect of pH on the CoWP Films Electrodeposited in Alkali-Metal-Free Electrolytes

Abstract
CoWP films were electrodeposited in alkali-metal-free electrolytes, and the effects of pH of the electrolyte on the film characteristics such as current density, thickness, composition, and structure were investigated. Larger variation of the CoWP film composition could be made by changing the pH of electrolyte from 3.5 to 8.5. The films deposited from very acidic solutions contained larger amounts of tungsten and smaller cobalt. Regardless of pH of the electrolyte, the CoWP film had amorphous-like structure, indicating that the CoWP film electrodeposited in alkali-metal-free electrolytes could be an effective capping/barrier layer for copper interconnections. Index Terms - Alkali-metal-free electrolyte, Barrier layer, CoWP film, Electrodeposition, pH