Adaptive electric field shielding in an electroplating processor using agitator geometry and motion control

An electroplating method, comprising:

• placing a wafer into contact with liquid electrolyte in a vessel;
• conducting ionic current through the liquid electrolyte;
• moving an agitator below the wafer with a movement that selectively shields a portion of the wafer;
• with the agitator having a stagger movement so that the time-averaged presence of a first side of the agitator over a first side of the wafer is greater than over a second side of the wafer.

An electroplating method, comprising:

• placing a wafer into contact with liquid electrolyte in a vessel;
• conducting ionic current through the liquid electrolyte;
• moving an agitator below the wafer with a movement that selectively shields a portion of the wafer;
• with the agitator having an array of ribs, a top side, a bottom side, a first side and a second side, and with the first side of the agitator having fewer ribs than the second side of the agitator.