Patent ID: 7750645

Claim:
In a plasma reactor including a controller and an RF or electrical power generator for processing a workpiece supported on a workpiece support pedestal having at least one electrode, a method of providing arc detection, comprising: sensing first transient voltages or currents on a conductor coupled to said workpiece; comparing in a first comparator the transient voltages or currents with a threshold level stored in said comparator; transmitting from said first comparator an arc flag signal whenever a transient voltage or current is sensed that exceeds said threshold level; deactivating said power generator in response to said arc flag signal; downloading a process recipe to be performed by said reactor; for each one of at least respective process steps in said process recipe, determining from RF power levels specified for the respective process step a threshold level for said first comparator that exceeds an expected noise level of the process step; at the beginning of each of said at least respective process steps, replacing in said first comparator the threshold level with a threshold level determined for the current process step.