Abstract: Methods and systems for controlling temperatures in plasma processing chamber with reduced controller response times and increased stability. Temperature control is based at least in part on a feedforward control signal derived from a plasma power input into the processing chamber. A feedforward control signal compensating disturbances in the temperature attributable to the plasma power may be combined with a feedback control signal counteracting error between a measured and desired temperature.

Abstract: Methods and systems for controlling temperatures in plasma processing chamber with reduced controller response times and increased stability. Temperature control is based at least in part on a feedforward control signal derived from a plasma power input into the processing chamber. A feedforward control signal compensating disturbances in the temperature attributable to the plasma power may be combined with a feedback control signal counteracting error between a measured and desired temperature.

Abstract: Methods and systems for controlling temperatures in plasma processing chamber with reduced controller response times and increased stability. Temperature control is based at least in part on a feedforward control signal derived from a plasma power input into the processing chamber. A feedforward control signal compensating disturbances in the temperature attributable to the plasma power may be combined with a feedback control signal counteracting error between a measured and desired temperature.

Abstract: Methods and systems for controlling temperatures in plasma processing chamber via pulsed application of heating power and pulsed application of cooling power. In an embodiment, temperature control is based at least in part on a feedforward control signal derived from a plasma power input into the processing chamber. In further embodiments, fluid levels in each of a hot and cold reservoir coupled to the temperature controlled component are maintained in part by a passive leveling pipe coupling the two reservoirs. In another embodiment, digital heat transfer fluid flow control valves are opened with pulse widths dependent on a heating/cooling duty cycle value and a proportioning cycle having a duration that has been found to provide good temperature control performance.

Abstract: Methods and systems for controlling temperatures in plasma processing chamber via pulsed application of heating power and pulsed application of cooling power. In an embodiment, temperature control is based at least in part on a feedforward control signal derived from a plasma power input into the processing chamber. In further embodiments, fluid levels in each of a hot and cold reservoir coupled to the temperature controlled component are maintained in part by a passive leveling pipe coupling the two reservoirs. In another embodiment, digital heat transfer fluid flow control valves are opened with pulse widths dependent on a heating/cooling duty cycle value and a proportioning cycle having a duration that has been found to provide good temperature control performance.

Abstract: Methods and systems for controlling temperatures in plasma processing chamber via pulsed application of heating power and pulsed application of cooling power. In an embodiment, temperature control is based at least in part on a feedforward control signal derived from a plasma power input into the processing chamber. In further embodiments, fluid levels in each of a hot and cold reservoir coupled to the temperature controlled component are maintained in part by a passive leveling pipe coupling the two reservoirs. In another embodiment, digital heat transfer fluid flow control valves are opened with pulse widths dependent on a heating/cooling duty cycle value and a proportioning cycle having a duration that has been found to provide good temperature control performance.

Abstract: Methods and systems for adapting and/or tuning feedforward control parameters in a plasma processing chamber. In embodiments, a dependent process parameter, such as a chamber component temperature, is controlled with a feedforward control algorithm based on one or more independent process parameters, such as RF power. A control algorithm may calculate steady-state deviation of the dependent parameter from a process recipe setpoint, estimate an amount by which an existing control gain coefficient is to be changed to better achieve the setpoint, associate the new control gain coefficient with the particular recipe operation, and store the new control gain coefficient for subsequent execution of the recipe operation. In embodiments, the amount by which a gain coefficient is to be changed is based on a model function derived from a lookup table associating gain coefficients with setpoints of the dependent process parameter and values of the independent process parameter.

Abstract: A stacked proportioning valve having a body with at least two sets of ports disposed at different positions along a longitudinal length of the body, each set of ports including at least three ports at different angular positions to couple to fluid conduits, a rotor disposed in the valve body has at least two sections stacked along the longitudinal length, each section comprising three fluid channels in longitudinal alignment with one of the sets of ports, and a drive shaft affixed to the rotor, the drive shaft to rotate the rotor over angular positions to fluidly couple together pairs of ports in each of the sets of ports synchronously as a function of the rotor's angular position. In embodiments a component of a plasma processing chamber, such as a plasma etch chamber is fluidly coupled by the stack proportioning valve to reservoirs of both a hot and cold chiller.

Abstract: A stacked proportioning valve having a body with at least two sets of ports disposed at different positions along a longitudinal length of the body, each set of ports including at least three ports at different angular positions to couple to fluid conduits, a rotor disposed in the valve body has at least two sections stacked along the longitudinal length, each section comprising three fluid channels in longitudinal alignment with one of the sets of ports, and a drive shaft affixed to the rotor, the drive shaft to rotate the rotor over angular positions to fluidly couple together pairs of ports in each of the sets of ports synchronously as a function of the rotor's angular position. In embodiments a component of a plasma processing chamber, such as a plasma etch chamber is fluidly coupled by the stack proportioning valve to reservoirs of both a hot and cold chiller.

Abstract: Polymer is removed from the backside of a wafer held on a support pedestal in a reactor using an arcuate side gas injection nozzle extending through the reactor side wall with a curvature matched to the wafer edge and supplied with plasma by-products from a remote plasma source.

Abstract: In a plasma reactor having an electrostatic chuck, wafer voltage may be determined from RF measurements at the bias input using previously determined constants based upon transmission line properties of the bias input, and this wafer voltage may be used to accurately control the DC wafer clamping voltage.

Abstract: Methods and systems for controlling temperatures in plasma processing chamber via pulsed application of heating power and pulsed application of cooling power. In an embodiment, temperature control is based at least in part on a feedforward control signal derived from a plasma power input into the processing chamber. In further embodiments, fluid levels in each of a hot and cold reservoir coupled to the temperature controlled component are maintained in part by a passive leveling pipe coupling the two reservoirs. In another embodiment, digital heat transfer fluid flow control valves are opened with pulse widths dependent on a heating/cooling duty cycle value and a proportioning cycle having a duration that has been found to provide good temperature control performance.

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: Methods and systems for controlling temperatures in plasma processing chamber with reduced controller response times and increased stability. Temperature control is based at least in part on a feedforward control signal derived from a plasma power input into the processing chamber. A feedforward control signal compensating disturbances in the temperature attributable to the plasma power may be combined with a feedback control signal counteracting error between a measured and desired temperature.

Abstract: A process is provided for removing polymer from a backside of a workpiece and/or photoresist from a front side of the workpiece. For backside polymer removal, the wafer is positioned near the ceiling to above a localized or remote plasma source having a side outlet through the sidewall of the chamber, and backside polymer is removed by rotating the workpiece while flowing plasma by-products from the side outlet to the wafer backside. For front side photoresist removal, the wafer is positioned away from the ceiling and below the side outlet of the localized plasma source, and front side photoresist is remove by rotating the workpiece while flowing plasma by-products from the side outlet to the wafer front side.

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: Embodiments of the present invention provide apparatus and method for front side protection while processing side and backside of a substrate. One embodiment of the present invention provides a showerhead configured to provide a purge gas to a front side of a substrate during a backside etch processing. The showerhead comprises a body configured to be disposed over the front side of the substrate. The body has a process surface configured to face the front side of the substrate. The process surface has an outer circular region, a central region, a middle region between the outer central region and the central region. The first plurality of holes are distributed in the outer circular region and configured to direct the purge gas towards an edge area of the front side of the substrate. No gas delivery hole is distributed within a substantial portion of the middle region.

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.

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.