Tungsten CMP is conducted with improved alignment mark integrity and reduced edge residue by employing a retaining ring having a mechanical hardness greater than about 85 durometer and a relatively soft polishing pad. Embodiments of the present invention include conducting CMP employing a carrier comprising a retaining ring additionally having a wear rate during CMP of less than about 1 mil per hour and a polishing pad having a hardness less than about 60 durometer. Suitable retaining ring materials include ceramics, quartz, polymers and fiber reinforced polymers.