Embodiments of a plug for use in an electrostatic chuck are provided herein. In some embodiments, a plug for use in an electrostatic chuck includes a polymer sleeve having a central opening; and a core disposed in the central opening of the polymer sleeve, the core having a central protrusion and a peripheral ledge, wherein an outer surface of the core includes a helical channel extending from a lower surface of the core towards the peripheral ledge to at least partially define a gas flow path through the plug, and wherein the peripheral ledge is disposed between an upper surface of the polymer sleeve and the lower surface of the core.