Substrate bias effects in plasma immersion ion implantation assisted deposition from a TiAl cathodic arc

Ti1−xAlx thin films were deposited on stainless steel substrates using plasma immersion ion implantation and deposition (PIIIAD). A cathodic arc was employed as a source of metallic ions from Ti0.5Al0.5 cathode and the arc plasma was guided by a curved magnetic field filter. The resultant thin films were analyzed using Auger electron spectroscopy (AES) and X-ray diffraction techniques. A dynamic profile simulation code, TRIDYN, based on binary collision approximation was applied to understand the Ti and Al profiles in the deposited thin film. The results indicate that the film composition and phase formation depend on the applied bias, duty cycle and off time energy of the bombarding ions. The results also indicate that in PIIIAD conditions, the assumption of time averaged d.c. bias is improper to describe pulsed biasing, with deposition, resputtering and ion implantation all occurring simultaneously.