Characteristics of high quality tantalum oxide films deposited by photoinduced chemical vapor deposition

A method is presented for the photodeposition of tantalum oxide films from tantalum ethoxide and nitrous oxide using 172 nm radiation. The composition of the tantalum oxides deposited by this technique was determined by x-ray photoelectron spectroscopy while the optical and electrical properties were characterized using ellipsometry, capacitance–voltage, and current–voltage techniques. A leakage current density as low as 3.2×10−7 A cm−2 at a voltage of 10 V is obtained for the as-grown films. This is several orders of magnitude better than for any other Ta2O5 films deposited using either conventional or plasma-chemical vapor deposition techniques.