Comparison of DC and AC arc thin film deposition techniques

DC and AC vacuum are evaporation comprise two techniques currently implemented for thin him deposition, each with specific technical aspects with regard to the discharge systems and their application fields. The DC are discharge at several 10 A up to 300 A is a well-established PVD technique to deposit hard coatings for a variety of applications. Examples of applications benefiting from this technique are cutting and forming tools. The primary function of hard coatings in this instance is to reduce friction and wear, and the standard coating materials employed are TiN, CrN, TiCN and AlTiN. In today's manufacturing industries, machines are designed to be fully automated to simplify the coating process which contains several steps like heating, cleaning and deposition. In contrast, AC are discharges are characterized by the repetition of short current pulses up to several 1000 A. They offer new possibilities including an increase of average current. This is especially important for applications that require plasma filtering to reduce or even avoid droplet deposition on substrates. Yet another useful property is the increase of plasma ionization compared to DC discharges. Applications like hard-amorphous carbon deposition and metal-interconnect deposition schemes in the semiconductor industry benefit from these superior plasma conditions. AC systems could be effectively introduced to industry by using the already well-established DC equipment base. Attaching AC evaporators to conventional systems serves customers in the coating market with new flexibility while maintaining the production proven reliability of their investments. (C) 1999 Elsevier Science S.A. All rights reserved.