Pinhole defect evaluation of TiN films prepared by dry coating process

Pinhole defects of TiN films deposited onto stainless steel by a few dry coating processes were evaluated potentiodynamically in a deaerated 0.5 kmol/m(3) H2SO4 + 0.05 kmol/m(3) KSCN solution at 298 K. The critical passivation current density i(crit) in the TiN films prepared by activated reactive evaporation method decreased considerably with increasing film thickness. For the greater than or equal to 1.5 mu m thick films prepared by r.f. reactive sputtering, and ion mixing and vapor deposition methods; however, there was an increasing tendency in i(crit) with cracking and/or peeling. Here, the area ratio of pinhole defects was evaluated by the ratio of i(crit) of a coated and a non-coated specimen. Such electrochemical evaluation was concluded to be a reliable technique for the pinhole defects of dry coating films. (C) 2000 Elsevier Science Ltd. All rights reserved.