Chemical mechanical planarization apparatus and methods

A chemical mechanical planarization apparatus, comprising:

• at least one platen;
• a polishing pad disposed on the platen, the polishing pad including a conductive metal layer and a polishing layer on the conductive metal layer;
• an insulation layer between and being directly contacted with the platen and the conductive metal layer of the polishing pad for electrically insulating the platen and the conductive metal layer of the polishing pad;
• a polishing head disposed above the platen and configured to clamp a to-be-polished wafer;
• a basic solution supply port disposed above the platen and configured to supply a basic solution onto a surface of the polishing layer of the polishing pad;
• a slurry arm disposed above the platen and configured to supply a polishing slurry onto the surface of the polishing layer;
• and
• a deionized water supply port configured to supply deionized water onto the surface of the polishing layer;
• and
• a power source having a first end physically connected to the platen and a second end physically connected to an edge of the conductive metal layer underlying the polishing layer to apply a voltage between the conductive metal layer and the platen to provide an interface potential to a bottom of the polishing layer through the conductive metal layer, wherein
• the insulation layer is parallel to a top surface of the platen and intervening between the conductive metal layer and the top surface of the platen, and the interface potential is applied to the parallelly arranged conductive metal layer and the platen so that the interface potential is uniformly distributed on the polishing layer through the conductive metal layer.