1. A system comprising:a chamber;
a multi-substrate holder to rotate about a vertical axis within the chamber and simultaneously deposits coating onto a plurality of substrates;
a pair of inlets, connected to a reservoir, to feed a first portion of a mixture of a reactive gas and water vapor into the chamber;
a pair of ring cathode targets,
wherein an inlet, of the pair of inlets, is disposed at a center of a ring cathode target of the pair of ring cathode targets; and
an anode to add a second portion of the mixture of the reactive gas and the water vapor to the chamber,
wherein the anode is positioned separately from the pair of ring cathode targets.