Chemical-mechanical polish (CMP) pad conditioner

An apparatus for planarizing semiconductor substrates comprising:

• a semiconductor substrate carrier and rotating polishing platen for chemically-mechanically polishing (CMP) the semiconductor substrate;
• a rotating polishing pad with a counter-electrode embedded within;
• a reservoir for a polishing slurry and means to dispense the slurry onto said rotating polishing pad;
• a rotating pad conditioner having an abrasive surface afixed thereon and a plurality of electrodes embedded in the pad conditioner holder and abrasive surface;
• 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;
• a means of applying a constant voltage between each electrode embedded in said rotating pad conditioner and said counter-electrode embedded within said rotating polishing pad;
• a means of measuring the current density in each said embedded electrode during the pad conditioning operation;
• a means of 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;
• a means of 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;
• a means of storing in a computer memory factors, generally called "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;
• a means to compare, for each electrode, the "computed Sherwood Number" during conditioning of a "used polish pad" to the "stored Sherwood Number" of a "fresh polish pad";
• a means to detect online the difference between the "computed Sherwood Number" and the "stored Sherwood Number;
• and
• a means to change online a conditioning parameter when a difference is detected between the "computed Sherwood Number" and the "stored Sherwood Number".