| 摘要 |
An apparatus ( 14 ) for and method of measuring impedance in a capacitively coupled plasma reactor system ( 10 ). The apparatus includes a high-frequency RF source ( 150 ) in electrical communication with an upper electrode ( 50 ). A first high-pass filter ( 130 ) is arranged between the upper electrode and the high-frequency RF source, to block low-frequency, high-voltage signals from the electrode RF power source ( 66 ) from passing through to the impedance measuring circuit A current-voltage probe ( 140 ) is arranged between the high-frequency source and the high-pass filter, and is used to measure the current and voltage of the probe signal with and without the plasma present. An amplifier ( 250 ) is electrically connected to the current-voltage probe, and a data acquisition unit ( 260 ) is electrically connected to the amplifier. A second high-pass filter ( 276 ) is electrically connected to a lower electrode ( 56 ) and to ground, so as to complete the isolation of the high-frequency circuit of the impedance measurement apparatus from the low-frequency, high-voltage circuit of the capacitively coupled plasma reactor system. A method of measuring the plasma impedance using the apparatus of the present invention is also disclosed.
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