Abstract: A dual frequency matching circuit for plasma enhanced semiconductor processing chambers having dual frequency cathodes is provided. The matching circuit includes two matching circuits with variable shunts combined to a common output. The matching circuit balances the load of the independent RF sources to that of the plasma in the processing chamber during operation.

Abstract: A method is provided for processing a workpiece in a plasma reactor chamber having electrodes including at least a ceiling electrode and a workpiece support electrode. The method includes coupling respective RF power sources of respective VHF frequencies f1 and f2 to either (a) respective ones of the electrodes or (b) a common one of the electrodes, where f1 is sufficiently high to produce a center-high non-uniform plasma ion distribution and f2 is sufficiently low to produce a center-low non-uniform plasma ion distribution. The method further includes adjusting a ratio of an RF parameter at the f1 frequency to the RF parameter at the f2 frequency so as to control plasma ion density distribution, the RF parameter being any one of RF power, RF voltage or RF current.

Abstract: Methods for monitoring process drift using plasma characteristics are provided. In one embodiment, a method for monitoring process drift using plasma characteristics includes obtaining metrics of current and voltage information of a first waveform coupled to a plasma during a plasma process formed on a substrate, obtaining metrics of current and voltage information of a second waveform coupled to the plasma during the plasma process formed on the substrate, the first and second waveforms having different frequencies, determining at least one characteristic of the plasma using the metrics obtained from each different frequency waveform, and adjusting the plasma process in response to the determined at least one characteristic of the plasma.

Abstract: A method and apparatus for controlling characteristics of a plasma in a semiconductor substrate processing chamber using a dual frequency RF source is provided. The method comprises supplying a first RF signal to a first electrode disposed in a processing chamber, and supplying a second RF signal to the first electrode, wherein an interaction between the first and second RF signals is used to control at least one characteristic of a plasma formed in the processing chamber.

Abstract: In one implementation, a method is provided for testing a plasma reactor multi-frequency matching network comprised of multiple matching networks, each of the multiple matching networks having an associated RF power source and being tunable within a tunespace. The method includes providing a multi-frequency dynamic dummy load having a frequency response within the tunespace of each of the multiple matching networks at an operating frequency of its associated RF power source. The method further includes characterizing a performance of the multi-frequency matching network based on a response of the multi-frequency matching network while simultaneously operating at multiple frequencies.

Abstract: An electrostatic chuck in a reactor chamber has a cathode electrode insulated from ground, a chucking electrode insulated from the cathode electrode and a dielectric layer overlying the chucking electrode that provides a workpiece support surface. A D.C. chucking voltage supply is coupled to the chucking electrode. An RF power generator is coupled to the cathode electrode. A voltage sensing apparatus is coupled to the chucking electrode and to the cathode electrode to monitor the voltage difference between them during discharge after removal of RF and DC power at the conclusion of processing. The reactor includes a controller programmed to raise the lift pins during electrode discharge as soon as the voltage sensing apparatus detects equal voltages simultaneously on the chucking and cathode electrodes.

Abstract: A method for processing a workpiece in a plasma reactor. The method comprises constraining plasma in the chamber away from the floor of the pumping annulus, providing an annular baffle while compensating for asymmetry of gas flow attributable to the pumping port, and providing a gas flow equalizer below the baffle having an eccentrically shaped opening. The method further includes modifying the radial distribution of plasma ion density and providing a magnetic plasma steering field having an edge high plasma ion density distribution tendency. The method further comprises locating the baffle at a sufficient distance below the workpiece to provide an edge low plasma ion density distribution tendency that compensates the edge high plasma ion density distribution tendency of the magnetic plasma steering field.

Abstract: Methods and apparatus for controlling characteristics of a plasma, such as the spatial distribution of RF power and plasma uniformity, are provided herein. In some embodiments, an apparatus for controlling characteristics of a plasma includes a resonator for use in conjunction with a plasma reactor, the resonator including a source resonator for receiving an RF signal having a first frequency; a return path resonator disposed substantially coaxially with, and at least partially within, the source resonator; and an outer conductor having the source resonator and the return path resonator disposed substantially coaxially with, and at least partially within, the outer conductor, the outer conductor for providing an RF ground connection.

Abstract: An apparatus configured to confine a plasma within a processing region in a plasma processing chamber. In one embodiment, the apparatus includes a ring that has a baffle having a plurality of slots and a plurality of fingers. Each slot is configured to have a width less than the thickness of a plasma sheath contained in the processing region.

Abstract: Apparatus and methods are provided for a power matching apparatus for use with a processing chamber. In one aspect of the invention, a power matching apparatus is provided including a first RF power input coupled to a first adjustable capacitor, a second RF power input coupled to a second adjustable capacitor, a power junction coupled to the first adjustable capacitor and the second adjustable capacitor, a receiver circuit coupled to the power junction, a high voltage filter coupled to the power junction and the high voltage filter has a high voltage output, a voltage/current detector coupled to the power junction and a RF power output connected to the voltage/current detector.

Abstract: Fluctuations in a plasma characteristic such as load impedance are compensated by a controller that modulates a stabilization RF generator coupled to the plasma having a frequency suitable for stabilizing the plasma characteristic, the controller being responsive to the fluctuations in the plasma characteristic.

Abstract: A method of processing a workpiece in a plasma reactor chamber in which plasma RF source and bias power is delivered into the chamber, by sensing fluctuations in a plasma parameter such as load impedance or reflected power at one of the generators, and modulating the output of the other generator to minimize the fluctuation.

Abstract: A plasma reactor, having source and bias RF power generators of different frequencies, is provided with a controller responsive to fluctuations in plasma load impedance measured at one of the generators to modulate the output of the other generator to compensate for the fluctuations.

Abstract: A method processing a workpiece in a plasma reactor chamber in which a first one of plural applied RF plasma powers is modulated in accordance with a time-varying modulation control signal corresponding to a desired process transient cycle. The method achieves a reduction in reflected power by modulating a second one of the plural plasma powers in response to the time-varying modulation control signal.

Abstract: In a plasma reactor employing source and bias RF power generators, plasma is stabilized against an engineered transient in the output of either the source or bias power generator by a compensating modulation in the other generator.

Abstract: A plasma reactor for processing a workpiece such as a semiconductor wafer using predetermined transients of plasma bias power or plasma source power has unmatched low power RF generators synchronized to the transients to minimize transient-induced changes in plasma characteristics.

Abstract: A workpiece is processed in a plasma reactor chamber using stabilization RF power delivered into the chamber, by determining changes in load impedance from RF parameters sensed at an RF source or bias power generator and resolving the changes in load impedance into first and second components thereof, and changing the power level of the stabilization RF power as a function one of the components of changes in load impedance.

Abstract: A method is provided in plasma processing of a workpiece for stabilizing the plasma against engineered transients in applied RF power, by modulating an unmatched low power RF generator in synchronism with the transient.

Abstract: Methods for determining characteristics of a plasma are provided. In one embodiment, a method for determining characteristics of a plasma includes obtaining metrics of current and voltage information for first and second waveforms coupled to a plasma at different frequencies, determining at least one characteristic of the plasma using the metrics obtained from each different frequency waveform. In another embodiment, the method includes providing a plasma impedance model of a plasma as a function of frequency, and determining at least one characteristic of a plasma using model. In yet another embodiment, the method includes providing a plasma impedance model of a plasma as a function of frequency, measuring current and voltage for waveforms coupled to the plasma and having at least two different frequencies, and determining ion mass of a plasma from model and the measured current and voltage of the waveforms.

Abstract: An apparatus configured to confine a plasma within a processing region in a plasma processing chamber. In one embodiment, the apparatus includes a ring that has a baffle having a plurality of slots and a plurality of fingers. Each slot is configured to have a width less than the thickness of a plasma sheath contained in the processing region.