Abstract: A method for creating a dielectric coating on a substrate produces near bulk density metal oxide coatings with extremely low surface roughness, microstructure and low defect density. The coatings have a low scatter of less than 50 ppm, low loss of less than 100 ppm, and an environmental stability of 0.1 or less spectral shift. A high vacuum chamber is provided which includes a substrate carrier device, an electron beam gun, a substrate, an evaporant source of coating material, a plasma bridge neutralizer and an ion gun. Coating material is evaporated with the electron beam gun to form a coating material evaporant that is directed to the substrate. An ion gun is directed toward the substrate and produces ions that arrive substantially simultaneously with the coating material evaporant at the substrate. The ions provide a momentum assist to the coating material. The result is a formation of a desirable dielectric thin film of coating material on the substrate.