A sputter deposition method and system for producing a metal oxide film, especially a dielectric standoff layer of a thin film/nanolayer capacitor. A noble gas, such as argon, is used to sputter metal ions from a metal target, such as niobium, in the presence of a partial pressure of oxygen in a vacuum chamber. And an oxygen-to-noble gas flow ratio entering the vacuum chamber is controlled by a flow controller to be within an operating range defined between a predetermined lower limit (such as 30% O.sub.2/Ar for niobium oxide) associated with a minimum transparency/stoichiometric threshold and a predetermined upper limit (such as 80% O.sub.2/Ar for niobium oxide) associated with a maximum roughness/porosity threshold, so that a reaction between the sputtered metal ions and the oxygen produces a substantially transparent metal oxide film with a substantially smooth non-porous surface.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 The United States Government has rights in this invention pursuant to Contract No. DE-AC52-07NA27344 between the United States Department of Energy and Lawrence Livermore National Security, LLC for the operation of Lawrence Livermore National Laboratory.