Method and apparatus for real time metal film thickness measurement

A metrological monitoring system configured to provide real-time thickness data with minimal inaccuracies, comprising:

• a first group of sensors configured to generate data representing a thickness map associated with a wafer located within a detection region of the first group of sensors, the thickness map generated prior to a processing operation;
• a second group of sensors configured to detect a thickness at a location on the wafer corresponding to one of the second group of sensors during a processing operation;
• and
• a computing device in communication with the first group of sensors and the second group of sensors, the computing device enabled to remove inaccuracies introduced into the thickness data at the location from a conductive body through the application of a calibration coefficient determined from the data representing the thickness map.

A method for calibrating an eddy current sensor to substantially eliminate inaccuracies introduced by the presence of third bodies within a detection region of the eddy current sensor, comprising:

• scanning a surface of a wafer in an absence of third bodies;
• generating a calibration coefficient from data captured by the scanning;
• transferring the wafer to a processing station;
• detecting a signal indicating a thickness of the wafer in a presence of third bodies;
• and
• applying the calibration coefficient to the signal to remove inaccuracies caused by the third bodies.