NUCLEATION AND GROWTH MECHANISMS IN ION-PLATED TIN FILMS ON STEEL SUBSTRATES

Cross-sectional transmission electron microscopy was used to investigate the nucleation and growth characteristics of TiN films, ion plated on tool steel substrates with an α-Ti underlayer (about 100 nm thick). It was found that (1) at 100 °C, the underlayer α-Ti remains unchanged and exhibits a layer and island growth mode; (2) at 300 and 500 °C, the underlayer may tranform into a TiC phase on M50 steel, and (3) the growth behavior of TiN films was controlled primarily by the reaction thermodynamics and diffusion rates of titanium and nitrogen adatoms. Model relationships based on microscopic evidence together with kinetic and thermodynamic considerations were established to describe the nucleation and growth mechanisms of ion-plated TiN films under the deposition conditions explored in this study. © 1990.