Chemical-mechanical polish (CMP) pad conditioner

A method for conditioning a polishing pad comprising the steps of:

• providing said polishing pad affixed to a rotatable polishing platen, said polishing pad having a counter-electrode embedded therein;
• providing a rotating pad conditioner having an abrasive surface affixed thereon, a pad conditioner holder, and a plurality of electrodes embedded in the pad conditioner holder and abrasive surface;
• providing a means for holding said abrasive surface of said rotating pad conditioner in juxtaposition relative to said rotating polishing pad with an applied pressure between the pad conditioner and the polishing pad;
• dispensing a polishing slurry onto said rotating polishing pad;
• applying a constant voltage between each electrode embedded in said rotating pad conditioner and said counter-electrode embedded within said rotating polishing pad;
• measuring current density in each said embedded electrode during the pad conditioning operation;
• storing in a computer memory data for current density versus polish pad conditioning time for each said electrode among the plurality of electrodes embedded in said rotating pad conditioner;
• integrating the measured current density with polish pad conditioning time for each said electrode among the plurality of electrodes embedded in said rotating pad conditioner;
• storing in a computer memory factors, known as Sherwood Numbers, which are the integrated current density with polish pad conditioning time for each said electrode among the plurality of electrodes embedded in said rotating pad conditioner;
• comparing, for each electrode, a computed Sherwood Number during conditioning of a used polish pad to a stored Sherwood Number from a fresh polish pad;
• detecting the difference between the computed Sherwood Number and the stored Sherwood Number;
• and
• changing a conditioning parameter when a difference is detected between the computed Sherwood Number and the stored Sherwood Number.