A new generation of filtered arc sources for ultrathin top coats on magnetic hard disks

Filtered cathodic arc deposition is a promising candidate as an industrial PVD technology for the deposition of challenging films in microelectronics and microsystems. This technique has proven its superiority of depositing high quality films compared to conventional arc applications in numerous laboratory tests. In advanced sources, the number of droplets is reduced to less then 1 millionth corresponding to less than 1 μm size particle/cm2, good enough for many advanced tool coatings but still insufficient for such highly demanding applications as the deposition of the top coat on a hard disk. In the present paper, recent improvements of the filtered high current pulsed arc (Φ-HCA) technique are described, resulting in a nearly complete droplet elimination to only a few 10-nm size particles/m2. With the Φ-HCA-source, we are able to produce pinhole-free corrosion protective carbon films with thickness down to 1.7 nm. The thickness profile and uniformity on disk is adjustable by a magnetic field array. The deposition rate is 3–5 nm/s; therefore, the coating time is below one second per disk. The magnetic layer is left undamaged during the Φ-HCA deposition process. These aspects are very important for industrial disk production efficiency. Strong particle reduction due to a magnetic filter tube is confirmed by repeatable glide tests. In several important tests, we showed that the Φ-HCA source is capable of producing carbon layers within a realistic disk production environment with a yield of approximately 93%, which proved to be comparable to current industrial technology. Apart from the hard disk coating, the current Φ-HCA source is a carbon deposition technique with high potential for many other industrial applications, e.g. for acoustic sensors, selective ion-beam mask-layer and applications needing thermal conductivity layer, etc.