Inductive plasma processor including current sensor for plasma excitation coil

• Main Authors: Veltrop, Robert G, Chen, Jian J, Wicker, Thomas E
• Format: Patent
• Language: English
• Published: 24.06.2003

The present invention relates generally to inductive plasma processors including an RF excitation coil and more particularly to such a processor including a shielded current sensor coupled to a low voltage portion of a branch including a winding of the coil. An inductive plasma processor includes an RF plasma excitation coil having plural windings, each having a first end connected in parallel to be driven by a single RF source via a single matching network. Second ends of the windings are connected to ground by termination capacitors, in turn connected by a lead to ground. A current sensor including a winding around a toroidal core is coupled to the lead between each termination capacitor and ground. The current sensor is surrounded by a grounded shield. There is minimum electromagnetic interference from an ambient RF environment to the current sensor, to provide an accurate current sensor.