High through-put Cu CMP is achieved with reduced erosion and dishing by a multi-step
polishing technique. Deposited Cu is polished with fixed abrasive polishing pads
initially at a high removal rate and subsequently at a reduced removal rate and
high Cu:barrier layer (Ta) selectivity. Embodiments of the present invention include
reducing dishing by: controlling platen rotating speeds; increasing the concentration
of active chemicals; and cleaning the polishing pads between wafers. Embodiments
also include removing particulate material during CMP by increasing the flow rate
of the chemical agent or controlling the static etching rate between about 100
and about 150 per minute, and recycling the chemical agent. Embodiments
further include flowing an inhibitor across the wafer surface after each CMP step
to reduce the static etching rate.