A method of making a showerhead for a semiconductor processing apparatus is disclosed. In one embodiment, the method includes providing a substrate; forming first holes in the substrate; forming a protective film on the substrate, where the protective film covers sidewalls of the first holes; and forming second holes in the substrate, where a part of the protective film within the first holes is removed. In another embodiment, the method includes providing a substrate; forming islands on the substrate; forming a protective film on the substrate, where the protective film does not cover the tops of the islands; and forming holes in the islands.