Abstract: Versatile temperature control systems adaptable to many different applications employ different states and proportions of a pressurized dual phase medium in direct contact with a thermal load. In one aspect of the invention, thermal energy generated by pressurization of a gaseous medium is stored at a selected temperature level so that it is later readily accessible. In addition, in accordance with the invention temperature control of a two-phase medium can be exercised across selectable dynamic ranges and with different resolutions. In accordance with such features, the control can be exerted by varying the input flow rate of a mixture applied to a thermal load, or by controlling the back pressure of the flow through the thermal load. In accordance with another feature of the invention, substantial energy conservation can be effected by employing an ambient temperature evaporator configuration between the thermal load and the input to the compressor.

Abstract: In a temperature control system using a controlled mix of high temperature pressurized gas and a cooled vapor/liquid flow of the same medium to cool a thermal load to a target temperature in a high energy environment, particular advantages are obtained in precision and efficiency by passing at least a substantial percentage of the cooled vapor/liquid flow through the thermal load directly, and thereafter mixing the output with a portion of the pressurized gas flow. This “post load mixing” approach increases the thermal transfer coefficient, improves control and facilities target temperature change. Ad added mixing between the cooled expanded flow and a lesser flow of pressurized gas also is used prior to the input to the thermal load. A further feature, termed a remote “Line Box”, enables transport of the separate flows of the two phase medium through a substantial spacing from pressurizing and condensing units without undesired liquefaction in the transport lines.

Abstract: A temperature control system is disclosed where thermal energy generated by pressurization of a gaseous medium is stored at a selected temperature level so that it is later readily accessible. Temperature control of a two-phase medium is exercised across selectable dynamic ranges and with different resolutions and the control can be exerted by varying the input flow rate of a mixture applied to a thermal load, or by controlling the back pressure of the flow through the thermal load.

Abstract: In a temperature control system using a controlled mix of high temperature pressurized gas and a cooled vapor/liquid flow of the same medium to cool a thermal load to a target temperature in a high energy environment, particular advantages are obtained in precision and efficiency by passing at least a substantial percentage of the cooled vapor/liquid flow through the thermal load directly, and thereafter mixing the output with a portion of the pressurized gas flow. This “post load mixing” approach increases the thermal transfer coefficient, improves control and facilities target temperature change. Ad added mixing between the cooled expanded flow and a lesser flow of pressurized gas also is used prior to the input to the thermal load. A further feature, termed a remote “Line Box”, enables transport of the separate flows of the two phase medium through a substantial spacing from pressurizing and condensing units without undesired liquefaction in the transport lines.

Abstract: A temperature control system is disclosed where thermal energy generated by pressurization of a gaseous medium is stored at a selected temperature level so that it is later readily accessible. Temperature control of a two-phase medium is exercised across selectable dynamic ranges and with different resolutions and the control can be exerted by varying the input flow rate of a mixture applied to a thermal load, or by controlling the back pressure of the flow through the thermal load.

Abstract: In a temperature control system using a controlled mix of high temperature pressurized gas and a cooled vapor/liquid flow of the same medium to cool a thermal load to a target temperature in a high energy environment, particular advantages are obtained in precision and efficiency by passing at least a substantial percentage of the cooled vapor/liquid flow through the thermal load directly, and thereafter mixing the output with a portion of the pressurized gas flow. This “post load mixing” approach increases the thermal transfer coefficient, improves control and facilities target temperature change. Ad added mixing between the cooled expanded flow and a lesser flow of pressurized gas also is used prior to the input to the thermal load. A further feature, termed a remote “Line Box”, enables transport of the separate flows of the two phase medium through a substantial spacing from pressurizing and condensing units without undesired liquefaction in the transport lines.

Abstract: Versatile temperature control systems adaptable to many different applications employ different states and proportions of a pressurized dual phase medium in direct contact with a thermal load. In one aspect of the invention, thermal energy generated by pressurization of a gaseous medium is stored at a selected temperature level so that it is later readily accessible. In addition, in accordance with the invention temperature control of a two-phase medium can be exercised across selectable dynamic ranges and with different resolutions. In accordance with such features, the control can be exerted by varying the input flow rate of a mixture applied to a thermal load, or by controlling the back pressure of the flow through the thermal load. In accordance with another feature of the invention, substantial energy conservation can be effected by employing an ambient temperature evaporator configuration between the thermal load and the input to the compressor.

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: In a temperature control system using a controlled mix of high temperature pressurized gas and a cooled vapor/liquid flow of the same medium to cool a thermal load to a target temperature in a high energy environment, particular advantages are obtained in precision and efficiency by passing at least a substantial percentage of the cooled vapor/liquid flow through the thermal load directly, and thereafter mixing the output with a portion of the pressurized gas flow. This “post load mixing” approach increases the thermal transfer coefficient, improves control and facilities target temperature change. Ad added mixing between the cooled expanded flow and a lesser flow of pressurized gas also is used prior to the input to the thermal load. A further feature, termed a remote “Line Box”, enables transport of the separate flows of the two phase medium through a substantial spacing from pressurizing and condensing units without undesired liquefaction in the transport lines.

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: In a temperature control system using a controlled mix of high temperature pressurized gas and a cooled vapor/liquid flow of the same medium to cool a thermal load to a target temperature in a high energy environment, particular advantages are obtained in precision and efficiency by passing at least a substantial percentage of the cooled vapor/liquid flow through the thermal load directly, and thereafter mixing the output with a portion of the pressurized gas flow. This “post load mixing” approach increases the thermal transfer coefficient, improves control and facilities target temperature change. Ad added mixing between the cooled expanded flow and a lesser flow of pressurized gas also is used prior to the input to the thermal load. A further feature, termed a remote “Line Box”, enables transport of the separate flows of the two phase medium through a substantial spacing from pressurizing and condensing units without undesired liquefaction in the transport lines.

Abstract: A system and method for controlling cooling of a thermal load having different cooling requirements in different sections based on direct thermal exchange using a two-phase refrigerant employs the pressure/temperature characteristics of the refrigerant to particular benefit for this multi-level cooling system. The two-phase refrigerant is first adjusted to have temperature/enthalpy characteristics chosen as the starting level for different cooling demands at related temperatures. After appropriate generation of a mixture of two-phase refrigerant initial reference temperature and pressure are established. Thereafter, incremental changes in the comprising hot gas and expanded cooled liquid/vapor, an temperature cooling medium area made by lowering the pressure by predetermined amounts, or alternatively by bypassing the pressure drop and proceeding to the next stage.

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: In a thermal control system of the type employing a two phase refrigerant that is first compressed and then is divided into a variable mass flow of refrigerant into a hot pressurized gas form and a differential remainder flow of cooled vapor derived from condensation and then thermal expansion, transitions between different temperature levels are enhanced by incremental variations of the mass flow at different control rates.

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.