Plasma-enhanced atomic layer deposition of titanium vanadium nitride

Abstract

The authors have studied the plasma-enhanced atomic layer deposition of TixV1−xN using tetrakis(dimethylamido) titanium, tetrakis(dimethylamido) vanadium, and nitrogen plasma. Through modification of the ratio of TiN to VN deposition cycles, the value of x can be well controlled. X-ray photoelectron spectroscopy analyses indicate that the films are slightly nitrogen-rich with 1%–10% carbon and oxygen. Resistivity estimated from four point probe measurements were 85 μΩ cm (TiN) and 107 μΩ cm (VN) for the binary nitrides with a maximum of 182 μΩ cm at x = 0.5. The binary nitride densities were 5%–6.5% lower than bulk material literature values with interstitial stoichiometry film densities transitioning continuously from the less dense TiN (5.04 g/cm3) to the more dense VN (5.69 g/cm3). Crystallinity increases with vanadium content as indicated by the XRD (111) and (020) peak heights and the Scherrer crystallite size estimates. Films demonstrated excellent tribological properties with wear rates of 1.1 × 10−6 and 7.7 × 10−8 mm3/N m and friction coefficients of 0.33 and 0.38 for TiN and VN, respectively.