Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1660510 | Surface and Coatings Technology | 2008 | 5 Pages |
Multilayered niobium oxynitride films were deposited onto (100) Si using DC magnetron sputtering with a reactive gas pulsing process. The argon and nitrogen flows were kept constant during sputtering of a pure niobium target and the oxygen flow was pulsed during deposition. Pulse durations of T = 10, 40 and 100 s and duty cycles α = tON / T of 0.3, 0.6 and 0.9 were chosen (tON = injection time of high oxygen flow). A mounting triangle was used as the pulse shape for the oxygen injection.During thin film deposition the cathode voltage, Ucath, the O2 and N2 partial pressures, p(O2) and p(N2), were recorded. A delay of both parameters (Ucath, p(O2)) was observed after each pulse, for the return to the values during tOFF = T − tON (off-time of oxygen injection with high flow).High resolution scanning electron microscopy revealed a multilayered structure for coatings deposited with T = 40 and 100 s. Transmission electron microscopy was used to verify that also the coatings with T = 10 s possess a multilayered structure with a period of λ = 10 nm. Despite this low period small crystallites (< 7 nm) were present in these layers. The indentation hardness and the Youngs modulus were in the range of 8.3–16.5 GPa and 154–180 GPa, respectively.