A mass flow controller controls the delivery of a precursor to a mist generator. The precursor is misted utilizing a venturi in which a combination of oxygen and nitrogen gas is charged by a corona wire and passes over a precursor-filled throat. The mist is refined using a particle inertial separator, electrically filtered so that it comprises predominantly negative ions, passes into a velocity reduction chamber, and then flows into a deposition chamber through inlet ports in an inlet plate that is both a partition between the chambers and a grounded electrode. The inlet plate is located above and substantially parallel to the plane of the substrate on which the mist is to be deposited. The substrate is positively charged to a voltage of about 5000 volts. There are 440 inlet ports per square inch in an 39 square inch inlet port area of the inlet plate directly above the substrate. The inlet port area is approximately equal to the substrate area. An exhaust port defines a channel about the periphery of an exhaust plane parallel to and below the substrate plane.