Process control via valve position and rate of position change monitoring

摘要

A computer implemented method for endpointing an etch process comprising the acts of monitoring an attribute of a pressure control valve and determining an endpoint of the process based upon the monitored attribute. The monitored attribute includes the position of the pressure control valve or the rate of change of the pressure control valve. The method is advantageously employed in an in-situ cleaning process of a polymerized plasma chamber.