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: Apparatus for processing a substrate is disclosed herein. In some embodiments, a substrate support may include a substrate support having a support surface for supporting a substrate the substrate support having a central axis; a first electrode disposed within the substrate support to provide RF power to a substrate when disposed on the support surface; an inner conductor coupled to the first electrode about a center of a surface of the first electrode opposing the support surface, wherein the inner conductor is tubular and extends from the first electrode parallel to and about the central axis in a direction away from the support surface of the substrate support; an outer conductor disposed about the inner conductor; and an outer dielectric layer disposed between the inner and outer conductors, the outer dielectric layer electrically isolating the outer conductor from the inner conductor. The outer conductor may be coupled to electrical ground.

Abstract: Methods and apparatus for controlling the temperature of a substrate during processing are provided herein. In some embodiments, an apparatus for retaining and controlling substrate temperature may include a puck of dielectric material; an electrode disposed in the puck proximate a surface of the puck upon which a substrate is to be retained; and a plurality of heater elements disposed in the puck and arranged in concentric rings to provide independent temperature control zones.

Abstract: An electrostatic chuck assembly including a dielectric layer with a top surface to support a workpiece. A cooling channel base disposed below the dielectric layer includes a plurality of inner fluid conduits disposed beneath an inner portion of the top surface, and a plurality of outer fluid conduits disposed beneath an outer portion of the top surface. A chuck assembly includes a thermal break disposed within the cooling channel base between the inner and outer fluid conduits. A chuck assembly includes a fluid distribution plate disposed below the cooling channel base and the base plate to distribute a heat transfer fluid delivered from a common input to each inner or outer fluid conduit. The branches of the inner input manifold may have substantially equal fluid conductance.

Abstract: A plasma reactor for processing a workpiece includes a reactor chamber, an electrostatic chuck within the chamber having a top surface for supporting a workpiece and having indentations in the top surface that form enclosed gas flow channels whenever covered by a workpiece resting on the top surface. The reactor further includes thermal control apparatus thermally coupled to the electrostatic chuck, an RF plasma bias power generator coupled to apply RF power to the electrostatic chuck, a pressurized gas supply of a thermally conductive gas, a controllable gas valve coupling the pressurized gas supply to the indentations to facilitate filling the channels with the thermally conductive gas for heat transfer between a backside of a workpiece and the electrostatic chuck at a heat transfer rate that is a function of the pressure against the backside of the workpiece of the thermally conductive gas.

Abstract: A plasma reactor for processing a workpiece includes a reactor chamber, an electrostatic chuck within the chamber for supporting a workpiece, an RF plasma bias power generator coupled to apply RF power to the electrostatic chuck and a refrigeration loop having an evaporator inside the electrostatic chuck with a refrigerant inlet and a refrigerant outlet. Preferably, the evaporator includes a meandering passageway distributed in a plane beneath a top surface of the electrostatic chuck. Preferably, refrigerant within the evaporator is apportioned between a vapor phase and a liquid phase. As a result, heat transfer between the electrostatic chuck and the refrigerant within the evaporator is a constant-temperature process. This feature improves uniformity of temperature distribution across a diameter of the electrostatic chuck.

Abstract: A plasma reactor having a reactor chamber and an electrostatic chuck with a surface for holding a workpiece inside the chamber includes a backside gas pressure source coupled to the electrostatic chuck for applying a thermally conductive gas under a selected pressure into a workpiece-surface interface formed whenever a workpiece is held on the surface and an evaporator inside the electrostatic chuck and a refrigeration loop having an expansion valve for controlling flow of coolant through the evaporator. The reactor further includes a temperature sensor in the electrostatic chuck and a memory storing a schedule of changes in RF power or wafer temperature.

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: A triaxial rod assembly for providing both RF power and DC voltage to a chuck assembly that supports a workpiece in a processing chamber during a manufacturing operation. In embodiments, a rod assembly includes a center conductor to be coupled to a chuck electrode for providing DC voltage to clamp a workpiece. Concentrically surrounding the center conductor is an annular RF transmission line to be coupled to an RF powered base to provide RF power to the chuck assembly. An insulator is disposed between the center conductor and RF transmission line. Concentrically surrounding the RF transmission line is a ground plane conductor coupled to a grounded base of the chuck to provide a reference voltage relative to the DC voltage. An insulator is disposed between the RF transmission line and the ground plane conductor.

Abstract: A method of controlling the temperature of a workpiece on a workpiece support in a plasma reactor includes placing coolant in a flow channel thermally coupled to the workpiece support, supporting a thermally conductive gas between the workpiece and the workpiece support to establish a backside gas pressure, providing sensors to measure the temperature of the workpiece support and the workpiece, and determining whether the rate of change in workpiece temperature is less or more than a rate limited by a thermal mass of the workpiece support. If the rate is less or equal, the thermal conditions of the coolant in the flow channel are changed to reduce a difference between the measured workpiece support temperature and a target workpiece support temperature. If the rate is more, the pressure of the thermally conductive gas is changed to reduce a difference between the measured workpiece temperature and a target workpiece temperature.

Abstract: A method of processing a workpiece in a plasma reactor having an electrostatic chuck for holding a workpiece in a chamber of the reactor includes providing a thermally conductive gas under pressure between a backside of the workpiece and a top surface of the electrostatic chuck, controlling the temperature of the electrostatic chuck, defining a desired workpiece temperature, measuring a current workpiece temperature or temperature related to the workpiece temperature and inputting the measured temperature to a thermal model representative of the electrostatic chuck. The method further includes determining from the thermal model a change in the pressure of the thermally conductive gas that would at least reduce the difference between the measured temperature and the desired temperature, and changing the pressure of the thermally conductive gas in accordance with the change determined from the thermal model.

Abstract: A plasma reactor having a reactor chamber and an electrostatic chuck having a surface for holding a workpiece inside the chamber includes inner and outer zone backside gas pressure sources coupled to the electrostatic chuck for applying a thermally conductive gas under respective pressures to respective inner and outer zones of a workpiece-surface interface formed whenever a workpiece is held on the surface, and inner and outer zone heat exchangers coupled to respective inner and outer zones of said electrostatic chuck. The reactor further includes inner and outer zone temperature sensors in inner and outer zones of the electrostatic chuck and a thermal model capable of simulating heat transfer through the inner and outer zones, respectively, between the evaporator and the surface based upon measurements from the inner and outer temperature sensors, respectively.

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: In a plasma reactor having an electrostatic chuck with an electrostatic chuck top surface for supporting a workpiece, thermal transfer medium flow channels in the interior of the electrostatic chuck, a method for controlling temperature of the workpiece during plasma processing includes circulating thermal transfer medium through the thermal transfer medium flow passages and supplying a thermally conductive gas between the workpiece and the electrostatic chuck top surface, and changing thermal transfer medium thermal conditions of thermal transfer medium flowing in the thermal transfer medium flow channels so as to change the temperature of the electrostatic chuck at a first rate limited by the thermal mass of the electrostatic chuck. The method further includes changing the backside gas pressure of the thermally conductive gas so as to change the temperature of the workpiece at a second rate faster than the first rate.

Abstract: Apparatus for controlling thermal uniformity of a substrate is provided herein. In some embodiments, the thermal uniformity of the substrate may be controlled to be more uniform. In some embodiments, the thermal uniformity of the substrate may be controlled to be non-uniform in a desired pattern. In some embodiments, an apparatus for controlling thermal uniformity of a substrate may include a substrate support having a support surface to support a substrate thereon; and a plurality of flow paths having a substantially equivalent fluid conductance disposed within the substrate support to flow a heat transfer fluid beneath the support surface.

Abstract: An apparatus for controlling thermal uniformity of a substrate-facing surface of a showerhead is provided herein. In some embodiments, the thermal uniformity of the substrate facing surface of the showerhead may be controlled to be more uniform. In some embodiments, the thermal uniformity of the substrate facing surface of the showerhead may be controlled to be non-uniform in a desired pattern. In some embodiments, an apparatus for controlling thermal uniformity of a substrate-facing surface of a showerhead may include a showerhead having a substrate facing surface and one or more plenums for providing one or more process gases through a plurality of gas distribution holes formed through the substrate facing surface of the showerhead; and a plurality of flow paths having a substantially equivalent fluid conductance disposed within the showerhead to flow a heat transfer fluid.

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: Embodiments of electrostatic chucks are provided herein. In some embodiments, an electrostatic chuck may include a body having a notched upper peripheral edge, defined by a first surface perpendicular to a body sidewall and a stepped second surface disposed between the first surface and a body upper surface, and a plurality of holes disposed through the body along the first surface; a plurality of fasteners disposed through the plurality of holes to couple the body to a base disposed beneath the body; a dielectric member disposed above the body upper surface to electrostatically retain a substrate; an insulator ring disposed about the body within the notched upper peripheral edge and having a stepped inner sidewall that mates with the stepped second surface to define a non-linear interface therebetween; and an edge ring disposed over the insulator ring, the non-linear interface limiting arcing between the edge ring and the fastener.

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.