Described herein are exemplary methods and apparatuses for fabricating a gas distribution showerhead assembly in accordance with one embodiment. In one embodiment, a method includes providing a gas distribution plate having a first set of through-holes for delivering processing gases into a semiconductor processing chamber. The first set of through-holes is located on a backside of the plate (e.g., Aluminum substrate). The method includes spraying (e.g., plasma spraying) a coating material (e.g., Ytrria based material) onto a cleaned surface of the gas distribution plate. The method includes removing (e.g., surface grinding) a portion of the coating material from the surface to reduce a thickness of the coating material. The method includes forming (e.g., UV laser drilling, machining) a second set of through-holes in the coating material such that the through-holes are aligned with the first-set of through-holes.