Patent ID: 7109788
Filing Date: 2006-09-19
Classification: H01J

Abstract:
1. An apparatus for improved impedance matching between an RF signal and a multi-segmented electrode in a plasma reactor powered by the RF signal, said apparatus comprising an electrode segment adapted to be connected to the RF signal by a circuit comprising: a phase shifter adapted to be connected to the RF signal; an amplifier connected to an output of said phase shifter; a matching network connected to an output of said amplifier, said matching network being configured to match an impedance of the amplifier with an impedance of said electrode segment; a modulation source configured to modulate the RF signal prior to receipt by said matching network; a directional coupler connected to an output of said matching network, said directional coupler having an output connected to said electrode segment; a demodulator being configured to receive an output signal from said directional coupler and a reference signal; and a control system connected to an output of said demodulator, said control system being configured to control said matching network such that said output signal of said directional coupler and said reference signal produce a signal of substantially minimized amplitude.