NON-INTRUSIVE MEASUREMENT OF A WAFER DC SELF-BIAS IN SEMICONDUCTOR PROCESSING EQUIPMENT

摘要

A direct (DC) voltage is applied to an electrode at a voltage value to clamp a workpiece to an electrostatic chuck in a processing chamber. The electrode is embedded into the electrostatic chuck. An electrostatic chuck current through the electrode at the DC voltage is measured. A DC self bias induced on the workpiece by a plasma is determined based on the electrostatic chuck current and the applied voltage.