Patent ID: 7096819
Filing Date: 2006-08-29
Classification: H01J

Abstract:
1. An inductive plasma processor for processing a workpiece, comprising a plasma excitation coil, the coil including plural parallel connected windings, a source for supplying power to the plural parallel connected windings, the source being connected to the plural parallel connected windings for causing current from the source to flow in parallel to the plural parallel connected windings, variable impedance arrangements respectively coupled with the plural parallel connected windings for varying the currents flowing from the source to each of the plural parallel connected windings, and a controller coupled to the source and components for (a) directly varying the total output power of the source and the total power the source supplies to the plural parallel connected windings and (b) varying values of components of the variable impedance arrangements so that for different distributions of electromagnetic fields the source is arranged to supply different amounts of total power and different relative currents to the plural parallel connected windings wherein the source is an RF source and the controller is arranged for varying the total power and the variable impedance arrangements so that for different distributions of electromagnetic fields generated by and supplied by the different windings to the plasma the current flowing in one of the windings remains substantially constant and the current in the remainder of the coil changes, each of the windings including first and second end terminals and each of the impedance arrangements including first and second variable capacitors, each of the first capacitors being connected in series with its respective first terminal for supplying RF energy from the RF source to the respective winding, each of the second capacitors being connected in series between its respective second terminal and ground, the controller being arranged for varying the values of the first and second variable capacitors.