Patent ID: 7733095

Claim:
A plasma reactor comprising: a chamber and a workpiece support pedestal in the chamber, the workpiece support pedestal comprising at least one electrode; an RF bias power generator having a first shut-off control input; an impedance matching circuit coupled to said at least one electrode; a first RF power conductor connected between said RF bias power generator and said impedance matching circuit; a first RF current sensor comprising: (a) a first ring conductor wrapped around a portion of said first RF power conductor; (b) a first inductive winding having a pair of ends and wrapped around a portion of said first ring conductor; a first arc detection comparator circuit having a first comparison threshold and having a first comparator output and having a first comparator input coupled to said first inductive winding; a process controller coupled to the first comparator output of said first arc detection comparator circuit and having a first process controller output coupled to said first shut-off control input of said RF bias power generator; a plasma RF power applicator capable of coupling RF power into said chamber; an RF source power generator having a second shut-off control input; a second impedance matching circuit coupled to said plasma RF power applicator; and a second RF power conductor connected between said RF source power generator and said second impedance matching circuit; a second RF current sensor comprising: (a) a second ring conductor wrapped around a portion of said second RF power conductor; and (b) a second inductive winding having a pair of ends and wrapped around a portion of said second ring conductor; and a second arc detection comparator circuit having a second comparison threshold, and having a second comparator input coupled to said second inductive winding.