Ion Beam Assisted Deposition Films Research Articles

Tribological behaviour of TiN Films deposited by high energy ion-beam-assisted deposition

Hardness measurements and abrasive and sliding wear tests were performed on TiN films deposited onto metal and ceramic substrates by reactive magnetron sputtering and by ion-beam-assisted deposition (IBAD) using 30 keV N2+ or 40 keV Ti+ ions. Composition-depth profiles obtained by Rutherford backscattering indicated significant intermixing of film and substrate at the interface. IBAD TiN films were found to be considerably softer and about 1/30 as abrasion resistant as reactively sputtered TiN films. The IBAD films were extremely adherent to either steel or ceramic substrates and reduced the dry sliding friction coefficient for steel-steel and ceramic-ceramic couples from roughly 0.7 to 0.2. The intermixing of film and substrate atoms can account for the excellent adherence of the IBAD films to otherwise incompatible ceramic substrates such as SiC. Based on these and previous studies, the tribomechanical properties of high energy IBAD TiN films appear to be relatively insensitive to processing parameters such as ion species, ion-to-atom arrival ratio and high vacuum conditions — an advantage in commercial film preparation.

Ion beam assisted deposition of substoichiometric silicon nitride

Thin films of substoichiometric silicon nitride of uniform composition have been produced by ion beam assisted deposition (IAD) of electron beam evaporated silicon on amorphized Si substrates. IAD films are found to have improved adhesion, increased density, and markedly lower oxygen contamination than non-IAD films produced simultaneously. The Reststrahlen features of the IR spectrum (due to local vibrational modes) are largely unaffected by crystallization at 900°C, indicating stable Si-N bond formation during IAD. The nitrogen content of the films was measured by RBS and in several cases by AES. Infrared reflection spectra were taken and analyzed to derive the index of refraction. The index decreases monotonically with increasing nitrogen fraction in agreement with the Lorentz-Lorentz relations for both the as deposited (amorphous) and annealed (crystalline) samples. The relationship between the incorporated nitrogen fraction and the ratio of the arriving nitrogen atom flux to the silicon atom flux is reported and modelled in a simple manner.