Plasma parameters such as plasma ion density, wafer voltage, etch rate and wafer current in the chamber are determined from external measurements on the applied RF bias electrical parameters such as voltage and current. The method includes sensing RF parameters corresponding to an input impedance, an...http://www.google.es/patents/US7553679?utm_source=gb-gplus-sharePatente US7553679 - Method of determining plasma ion density, wafer voltage, etch rate and wafer current from applied bias voltage and current
Method of determining plasma ion density, wafer voltage, etch rate and wafer ...
