The disclosure describes a plasma source assemblies comprising a differential screw assembly, an RF hot electrode, a top cover, an upper housing and a lower housing. The differential screw assembly is configured to provide force to align the plasma source assembly vertically matching planarity of a susceptor. More particularly, the differential screw assembly increases a distance between the top cover and the upper housing to align the gap with the susceptor. The disclosure also provides a better thermal management by cooling fins. A temperature capacity of the plasma source assemblies is extended by using titanium electrode. The disclosure provides a cladding material covering a portion of a first surface of RF hot electrode, a second surface of RF hot electrode, a bottom surface of RF hot electrode, a portion of a surface of the showerhead and a portion of lower housing surface.