Patent attributes
An impedance matching system includes an impedance matching network coupled between an alternating current (AC) generator and electrodes of a plasma chamber. The AC generator is configured to generate a multi-level pulse signal of cyclically recurring pulse intervals with differing amplitude levels. A controller or other device identifies each recurring pulse interval, and for each pulse interval, determines an impedance mis-match level between the AC generator and the electrodes, adjusts a configuration of the impedance matching network according to the determined impedance mis-match level, and stores information associated with the adjusted configuration. When an ensuing pulse interval occurs, the controller obtains the stored information from memory, adjusts the configuration of the impedance matching network according to the stored information, determines another impedance mis-match level between the AC generator and the electrodes, and adjusts the configuration of the impedance matching network to iteratively reduce the impedance mismatch level.
