Copper Chemical Mechanical Polishing was characterized in hydrogen peroxide and L - arginine based basic slurries. CMP and etch rate experiments were conducted to understand the complexing role of arginine in peroxide based slurries. Both polish and etch rate were studied for hydrogen peroxide concentration 0 to 10 vol% with 1 wt% L-arginine. The relative roles played by the both the chemicals were elucidated by electrochemical techniques. © 2006 Materials Research Society.