Gas flow for condensation reduction with a substrate processing chuck

A plasma processing system comprising:

• a plasma chamber;
• a plasma source to generate a plasma containing gas ions in the plasma chamber;
• and
• a workpiece holder in the chamber having a puck to carry the workpiece for fabrication processes, a top plate thermally coupled to the puck, a cooling plate fastened to and thermally coupled to the top plate, a base plate fastened to the cooling plate opposite the puck, a dry gas outlet of the base plate positioned between a central shaft and a periphery of the base plate, the dry gas outlet to supply a dry gas under pressure to a space between the base plate and the cooling plate, wherein the base plate has a groove configured to allow the dry gas to flow in and out of the groove to the space between the base plate and the cooling plate, the groove having a path from the dry gas outlet to the central shaft, wherein a portion of the path is from the periphery of the base plate to the central shaft, and a cylindrical bore through the cooling plate to allow the dry gas to flow between the base plate and the cooling plate to between the cooling plate and the top plate, the cylindrical bore being positioned so that the groove leads the dry gas to flow to the cylindrical bore.

A method comprising:

• attaching a workpiece to a puck of a carrier to carry the workpiece for fabrication processes, the carrier including a top plate thermally coupled to the puck, a cooling plate fastened to and thermally coupled to the top plate, and a base plate fastened to the cooling plate opposite the puck;
• applying a fabrication process to the workpiece in a processing chamber while the workpiece is attached to the carrier;
• and
• supplying a dry gas under pressure to an outlet of the base plate positioned between a central shaft and a periphery of the base plate during the fabrication process, the outlet to supply the dry gas under pressure to a space between the base plate and the cooling plate, wherein the base plate has a groove configured to allow the dry gas to flow in and out of the groove to the space between the base plate and the cooling plate, the groove having a path from the outlet to the central shaft, wherein a portion of the path is from the periphery of the base plate to the central shaft, and a cylindrical bore through the cooling plate to allow the dry gas to flow between the base plate and the cooling plate to between the cooling plate and the top plate, the cylindrical bore being positioned so that the groove leads the dry gas to flow to the cylindrical bore.