Deposition condition and pinhole defect density of CrN_x (1≥ x ≥ 0) Thin films formed by ion-beam-enhanced deposition

In order to produce a CrN_x (1 ≥ x ≥ 0) thin film with a tow pinhole defect density using an ion-beam-enhanced deposition method, the effect of deposition conditions, such as the N₂ gas flow rate, the beam current, the accelerator voltage, and the beam voltage of enhancement source, on the pinhole defect density was examined. CrN_x thin films were deposited on type 304 stainless steel substrates, and then anodic polarization carves of CrN_x-coated steels were measured in a deaerated 0.05 M H₂SO₄ + 0.005 M KSCN solution. Pinhole defect density was evaluated by the ratio of the critical passivation current density of CrN_x-coated steel to that of noncoated steel. It was found that the pinhole defect density was decreased with increasing the beam voltage of the enhancement source. The lowest pinhole defect density, 0.005 area %, was obtained by the following conditions: N₂ flow rate 5 sccm, Ar flow rate 3 sccm, beam current 20 mA, beam voltage 200 V, accelerator voltage 600 V, and film thickness 65 nm.