Advanced temperature control for wafer carrier in plasma processing chamber

A workpiece processing system comprising:

• a plasma chamber;
• a plasma source to generate a plasma containing gas ions in the plasma chamber;
• a workpiece holder in the chamber to hold the workpiece during plasma processing and to control the temperature of the workpiece, the workpiece holder having a fluid channel and a temperature sensor;
• a heat exchanger to provide a thermal fluid to the fluid channel of the workpiece holder and to receive the thermal fluid from the fluid channel, the thermal fluid in the fluid channel to control the temperature of the carrier during substrate processing;
• a proportional valve to control the rate of flow of thermal fluid from the heat exchanger to the fluid channel;
• a pneumatic valve between the heat exchanger and the fluid channel also to control the rate of flow of thermal fluid from the heat exchanger and the fluid channel;
• and
• a temperature controller to receive a measured temperature from a thermal sensor of the carrier and to control the proportional valve and the pneumatic valve in response to the measured temperature to adjust the rate of flow of the thermal fluid.

A method for processing a workpiece comprising:

• generating a plasma containing gas ions in a plasma chamber;
• applying the plasma to a workpiece on a workpiece holder;
• and
• regulating the temperature of the workpiece through a first thermal fluid channel in a first thermal zone and a second thermal fluid channel in a second thermal zone of the workpiece holder, using a heat exchanger to provide a thermal fluid to the fluid channels and to receive the thermal fluid from the fluid channels, the thermal fluid in the fluid channels to control the temperature of the workpiece carrier in the respective first and second thermal zones during substrate processing using a first valve coupled to the first fluid channel and a second valve in the second fluid channel to control the rate of flow of thermal fluid from the heat exchanger to the respective fluid channels and a temperature controller to receive a measured temperature from a first thermal sensor for the first thermal zone and a second thermal sensor of the second thermal zone of the workpiece holder and to control the first and the second valve in response to the measured temperature by applying a predictive model to adjust the rate of flow of the thermal fluid.