Exemplary substrate processing systems may include a chamber body defining a transfer region. The systems may include a first lid plate seated on the chamber body along a first surface of the first lid plate. The first lid plate may define a plurality of apertures through the first lid plate. The systems may include a plurality of lid stacks equal to a number of apertures of the plurality of apertures defined through the first lid plate. The systems may include a plurality of isolators. An isolator of the plurality of isolators may be positioned between each lid stack of the plurality of lid stacks and a corresponding aperture of the plurality of apertures defined through the first lid plate. The systems may include a plurality of dielectric plates. A dielectric plate of the plurality of dielectric plates may be seated on each isolator of the plurality of isolators.