Abstract: A point of use irrigation water fertigation system utilizes plasma production of nitrogen-bearing species. Soluble nitrogen-bearing species are generated using an atmospheric air plasma treatment of an irrigation water supply. A plasma is generated by a tube having an air intake. A high frequency generator generates atmospheric plasma. The end of the tube is placed above the surface of the irrigation water supply and the plasma emanating from the tube generates nitrogen species in the water. The non-thermal plasma discharge efficiently produces highly reactive radicals and NOx species that have impact on water chemistry including inactivation of microorganisms with high efficacy and accelerated removal of persistent organic pollutants such as perfluorinated compounds (PFCs) from water samples. Plasma ignition can be initiated with a low flow of helium gas injection. Upon ignition, the gas is transitioned to a helium/room air mix, immediately followed by a transition to ambient room air only.

Abstract: A point of use irrigation water fertigation system utilizes plasma production of nitrogen-bearing species. Soluble nitrogen-bearing species are generated using an atmospheric air plasma treatment of an irrigation water supply. A plasma is generated by a tube having an air intake. A high frequency generator generates atmospheric plasma. The end of the tube is placed above the surface of the irrigation water supply and the plasma emanating from the tube generates nitrogen species in the water. The non-thermal plasma discharge efficiently produces highly reactive radicals and NOx species that have impact on water chemistry including inactivation of microorganisms with high efficacy and accelerated removal of persistent organic pollutants such as perfluorinated compounds (PFCs) from water samples. Plasma ignition can be initiated with a low flow of helium gas injection. Upon ignition, the gas is transitioned to a helium/room air mix, immediately followed by a transition to ambient room air only.

Abstract: A substrate cleaning chamber includes a contoured ceiling electrode having an arcuate surface that faces a substrate support and has a variable cross-sectional thickness to vary the gap size between the arcuate surface and the substrate support to provide a varying plasma density across the substrate support. A dielectric ring for the cleaning chamber comprises a base, a ridge, and a radially inward ledge that covers the peripheral lip of the substrate support. A base shield comprises a circular disc having at least one perimeter wall. Cleaning and conditioning processes for the cleaning chamber are also described.

Abstract: A substrate cleaning chamber includes a contoured ceiling electrode having an arcuate surface that faces a substrate support and has a variable cross-sectional thickness to vary the gap size between the arcuate surface and the substrate support to provide a varying plasma density across the substrate support. A dielectric ring for the cleaning chamber comprises a base, a ridge, and a radially inward ledge that covers the peripheral lip of the substrate support. A base shield comprises a circular disc having at least one perimeter wall. Cleaning and conditioning processes for the cleaning chamber are also described.

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 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: 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: A method and apparatus for confining a plasma are provided herein. In one embodiment, an apparatus for confining a plasma includes a substrate support and a magnetic field forming device for forming a magnetic field proximate a boundary between a first region disposed at least above the substrate support, where a plasma is to be formed, and a second region, where the plasma is to be selectively restricted. The magnetic field has b-field components perpendicular to a direction of desired plasma confinement that selectively restrict movement of charged species of the plasma from the first region to the second region dependent upon the process conditions used to form the plasma.

Abstract: A method of processing a workpiece in a plasma reactor chamber includes coupling RF power via an electrode to plasma in the chamber, the RF power being of a variable frequency in a frequency range that includes a fundamental frequency f. The method also includes coupling the electrode to a resonator having a resonant VHF frequency F which is a harmonic of the fundamental frequency f, so as to produce VHF power at the harmonic. The method controls the ratio of power near the fundamental f to power at harmonic F, by controlling the proportion of power from the generator that is up-converted from f to F, so as to control plasma ion density distribution.

Abstract: A method is provided for processing a workpiece in a plasma reactor chamber. The method includes coupling, to a plasma in the chamber, power of an RF frequency via a ceiling electrode and coupling, to the plasma, power of at least approximately the same RF frequency via a workpiece support electrode. The method also includes providing an edge ground return path. The method further includes adjusting the proportion between (a) current flow between said electrodes and (b) current flow to the edge ground return path from said electrodes, to control plasma ion density distribution uniformity over the workpiece.

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 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: 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: RF ground return current flow is diverted away from asymmetrical features of the reactor chamber by providing bypass current flow paths. One bypass current flow path avoids the pumping port in the chamber floor, and comprises a conductive symmetrical grill extending from the side wall to the grounded pedestal base. Another bypass current flow path avoids the wafer slit valve, and comprises an array of conductive straps bridging the section of the sidewall occupied by the slit valve.

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: A method for processing a workpiece in a plasma reactor chamber includes coupling RF power at a first VHF frequency f1 to a plasma via one of the electrodes of the chamber, and providing a center ground return path for RF current passing directly between the ceiling electrode and the workpiece support electrode for the frequency f1. The method further includes providing a variable height edge ground annular element and providing a ground return path through the edge ground annular element for the frequency f1. The method controls the uniformity of plasma ion density distribution by controlling the distance between the variable height edge ground annular element and one of: (a) height of ceiling electrode or (b) height of workpiece support electrode.

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: In a plasma reactor chamber a ceiling electrode and a workpiece support electrode, respective RF power sources of respective VHF frequencies f1 and f2 are coupled to either respective ones of the electrodes or to 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. Respective center ground return paths are provided for RF current passing directly between the ceiling electrode and the workpiece support electrode for the frequencies f1 and f2, and an edge ground return path is provided for each of the frequencies f1 and f2. The impedance of at least one of the ground return paths is adjusted so as to control the uniformity of the plasma ion density distribution.