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 evaporators inside respective inner and outer zones of the electrostatic chuck and a refrigeration loop having respective inner and cuter expansion valves for controlling flow of coolant through the inner and outer evaporators respectively. 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: A method of transferring heat from or to a workpiece support in an RF coupled plasma reactor includes placing coolant in an internal flow channel that is located inside the workpiece support and transferring heat from or to the coolant by circulating the coolant through a refrigeration loop in which the internal flow channel of the workpiece support constitutes an evaporator of the refrigeration loop. The method further includes maintaining thermal conditions of the coolant inside the evaporator within a range in which heat exchange between the workpiece support and the coolant is primarily or exclusively through the latent heat of vaporization of the coolant.

Abstract: A system for improving the thermal efficiency of a thermal control loop in which refrigerant after compression and condensation is applied to an evaporator employs a subsidiary counter-current heat exchange intercepting refrigerant flow to maintain the quality of the refrigerant by exchanging thermal energy between the input flow and the output flow from the evaporator. The same principle is effective, with particular advantage when small connections have to be made, in systems using mixed phase media and using the concept of direct energy transfer with saturated fluid.

Abstract: A method of controlling wafer temperature in a plasma reactor by obtaining the next scheduled change in RF heat load on the workpiece, and using thermal modeling to estimate respective changes in wafer backside gas pressure and in coolant flow through a wafer support pedestal that would compensate for the next scheduled change in RF heat load, and making the respective changes in the backside gas pressure or in the coolant flow prior to the time of the next scheduled change.

Abstract: A system for improving the thermal efficiency of a thermal control loop in which refrigerant after compression and condensation is applied to an evaporator employs a subsidiary counter-current heat exchange intercepting refrigerant flow to maintain the quality of the refrigerant by exchanging thermal energy between the input flow and the output flow from the evaporator. The same principle is effective, with particular advantage when small connections have to be made, in systems using mixed phase media and using the concept of direct energy transfer with saturated fluid.

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 method of processing a workpiece in a plasma reactor having an electrostatic chuck for supporting the workpiece within a reactor chamber, the method including circulating a coolant through a refrigeration loop that includes an evaporator inside the electrostatic chuck, while pressurizing a workpiece-to-chuck interface with a thermally conductive gas, sensing conditions in the chamber including temperature near the workpiece and simulating heat flow through the electrostatic chuck in a thermal model of the chuck based upon the conditions.

Abstract: A system for improving the thermal efficiency of a thermal control loop in which refrigerant after compression and condensation is applied to an evaporator employs a subsidiary counter-current heat exchange intercepting refrigerant flow to maintain the quality of the refrigerant by exchanging thermal energy between the input flow and the output flow from the evaporator. The same principle is effective, with particular advantage when small connections have to be made, in systems using mixed phase media and using the concept of direct energy transfer with saturated fluid.

Abstract: A plasma reactor with a reactor chamber and an electrostatic chuck having 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, a thermal model capable of simulating heat transfer between the evaporator and the surface based upon measurements from the temperature sensor and an agile control processor coupled to the thermal model and governing the backside gas pressure source in response to predictions from the model of changes in the selected pressure that would bring the temperature measured by the sensor closer to a desired temperature.

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 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: 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: A system and method for controlling the temperature of a process tool uses the vaporizable characteristic of a refrigerant that is provided in direct heat exchange relation with the process tool. Pressurized refrigerant is provided as both condensed liquid and in gaseous state. The condensed liquid is expanded to a vaporous mix, and the gaseous refrigerant is added to reach a target temperature determined by its pressure. Temperature corrections can thus be made very rapidly by gas pressure adjustments. The process tool and the operating parameters will usually require that the returning refrigerant be conditioned and processed for compatibility with the compressor and other units, so that cycling can be continuous regardless of thermal demands and changes.

Abstract: A system for improving the thermal efficiency of a thermal control loop in which refrigerant after compression and condensation is applied to an evaporator employs a subsidiary counter-current heat exchange intercepting refrigerant flow to maintain the quality of the refrigerant by exchanging thermal energy between the input flow and the output flow from the evaporator. The same principle is effective, with particular advantage when small connections have to be made, in systems using mixed phase media and using the concept of direct energy transfer with saturated fluid.

Abstract: A system and method for controlling the temperature of a process tool uses the vaporizable characteristic of a refrigerant that is provided in direct heat exchange relation with the process tool. Pressurized refrigerant is provided as both condensed liquid and in gaseous state. The condensed liquid is expanded to a vaporous mix, and the gaseous refrigerant is added to reach a target temperature determined by its pressure. Temperature corrections can thus be made very rapidly by gas pressure adjustments. The process tool and the operating parameters will usually require that the returning refrigerant be conditioned and processed for compatibility with the compressor and other units, so that cycling can be continuous regardless of thermal demands and changes.

Abstract: A system and method for controlling the temperature of a process tool uses the vaporizable characteristic of a refrigerant that is provided in direct heat exchange relation with the process tool. Pressurized refrigerant is provided as both condensed liquid and in gaseous state. The condensed liquid is expanded to a vaporous mix, and the gaseous refrigerant is added to reach a target temperature determined by its pressure. Temperature corrections can thus be made very rapidly by gas pressure adjustments. The process tool and the operating parameters will usually require that the returning refrigerant be conditioned and processed for compatibility with the compressor and other units, so that cycling can be continuous regardless of thermal demands and changes.

Abstract: Systems and methods for heat exchange in accordance with the invention define adequately long-interchange distances for two fluids by wrapping a tube containing a first fluid about the wall of an inner cylindrical tank, within a gap formed with a second concentric tank. A second fluid is transmitted in the space defined between the turns of the tube and the two walls, providing effective short length thermal interchange through the tube walls. The tube is in the line contact with both tank walls and the fluids can flow rapidly over an adequately long length, so that high efficiency is provided in a low cost system.

Abstract: A system and method for controlling the temperature of a process tool uses the vaporizable characteristic of a refrigerant that is provided in direct heat exchange relation with the process tool. Pressurized refrigerant is provided as both condensed liquid and in gaseous state. The condensed liquid is expanded to a vaporous mix, and the gaseous refrigerant is added to reach a target temperature determined by its pressure. Temperature corrections can thus be made very rapidly by gas pressure adjustments. The process tool and the operating parameters will usually require that the returning refrigerant be conditioned and processed for compatibility with the compressor and other units, so that cycling can be continuous regardless of thermal demands and changes.