Abstract: Methods and apparatus for controlling power distribution in a substrate processing system are provided. In some embodiments, a substrate processing system including a process chamber having a substrate support and a processing region disposed above the substrate support; a first conduit disposed above the processing region to provide a portion of a first toroidal path that extends through the first conduit and across the processing region; a second conduit disposed above the processing region to provide a portion of a second toroidal path that extends through the second conduit and across the processing region; an RF generator coupled to the first and second conduits to provide RF energy having a first frequency to each of the first and second conduits; an impedance matching network disposed between the RF generator and the first and second conduits; and a power divider to control the amount of RF energy provided to the first and second conduits from the RF generator.

Abstract: Dose uniformity of a scanning ion implanter is determined. A base beam current is measured at the beginning and/or the end of a complete scan over the whole substrate area. This base beam current is measured at a time when the measurement should be unaffected by outgassing from a substrate being implanted and a base dose distribution map is then calculated for the scan in question. During the scan itself beam instability events are detected and the magnitude and position in the scan of the detected instability events is measured. Corresponding deviations in the calculated base dose map are determined and subtracted from the previously calculated base dose distribution map to provide a corrected distribution map. By determining overall dose uniformity substractively in this way, good overall accuracy can be obtained with lesser accuracy in the measurement of the beam instability events.

Abstract: A performance parameter for an ion implanter is obtained by monitoring vacuum pressure in a vacuum chamber of the implanter to identify pulses of said pressure caused by outgassing from the wafer surfaces during respective scans or groups of scans of the wafer through the ion beam. The pressure values are integrated during the identified pulses to provide a series of pulse pressure integral values which provide the performance parameter. An increase in the integral values indicates deterioration in vacuum system performance.