Abstract: Exemplary semiconductor processing systems may include a chamber body having a bottom plate. The systems may include a substrate support disposed within the chamber body. The substrate support may include a support plate and a shaft. The shaft may include a cooling hub that extends through the bottom plate. The shaft may include a ground shaft that is seated atop the cooling hub. The ground shaft may include a ceramic material. The systems may include an inner isolator coupled with a bottom of the support plate. The inner isolator may define an aperture therethrough that receives the shaft. The systems may include an outer isolator that is seated atop the inner isolator. Each of the inner isolator and the outer isolator may include a ceramic material.

Abstract: Exemplary choke plates for use in a substrate processing system may include a plate defining a first aperture through the plate and a second aperture through the plate. The second aperture may be laterally offset from the first aperture. The plate may include a flange that defines a purging inlet. The plate may include a rim defining a plurality of purging outlets that are fluidly coupled with the purging inlet. Each of the plurality of purging outlets may be fluidly coupled with the first aperture.