Vacuum processing chambers incorporating a moveable flow equalizer

A vacuum processing system, comprising:

• a first vacuum processing chamber including a first workpiece support disposed therein, the first workpiece support having a top surface spanning a first radial distance from a longitudinal axis of the first chamber, and a lower surface opposite the top surface;
• a second vacuum processing chamber including a second workpiece support disposed therein and having a top surface spanning a first radial distance from a longitudinal axis of the second chamber, and a lower surface opposite the top surface, wherein the second vacuum processing chamber is positioned adjacent to the first vacuum processing chamber and isolated from the first vacuum processing chamber by a shared interior chamber wall, and wherein a pump port shared by the first and second vacuum processing chambers is disposed in the shared interior chamber wall, to couple the first and second vacuum processing chambers to a shared vacuum pump;
• a first movable flow equalizer disposed in the first vacuum processing chamber between the first workpiece support and the shared pump port;
• and
• a second movable flow equalizer disposed in the second vacuum processing chamber between the second workpiece support and the shared pump port, wherein each of the first and second flow equalizers further comprise:
• an annular top surface spanning a second radial distance from the longitudinal axis of the respective chamber wherein at least a portion of the annular top surface underlying the workpiece support and spaced apart from the workpiece support lower surface by a first gap in a direction parallel to said longitudinal axis, said first gap extending over a radial distance where the first and second radial distances overlap, the first gap modulated by the movement of the flow equalizer along the longitudinal chamber axis;
• and
• a side surface concentrically surrounding a stem of the workpiece support along the longitudinal axis of the respective chamber, the stem extending a third radial distance that is less than the first radial distance, and the side surface disposed a radial distance from the stem to form a radial gap between the workpiece support and the flow equalizer which is smaller than a radial distance between the longitudinal axis of the respective chamber and the pump port, wherein the radial gap is fluidly coupled to the first gap to conduct gas from the first gap toward the pump port.