Synthesis of WC–Ni films using an arc ion plating system with attached solenoid coil

The formation and properties of WC–Ni thin films deposited on Si were studied. A cathodic tungsten carbide arc was used at room temperature to prepare the samples. In this paper, the effect of system parameters, such as external magnetic field, etc., were investigated. Without filtering, only condensed tungsten carbide droplets were observed on the substrate, while transparent films with few droplets were produced when a filter was used to reduce the number of macroparticles. Plasma floating potential and substrate current density were determined by voltage-current analyzer. The change of plasma states during cathodic arc discharges of tungsten carbide, under various magnetic fields of straight magnetic solenoid, was analyzed by optical emission spectroscopy (OES). In addition, an intensified camera system with a fiberoptically coupled high-resolution CCD was used for the estimating distribution of plasma density around the axis of the solenoid coil. Deposition rates of about 20 nm/min of WC–Ni film were determined with α-step. Scanning electron microscopy (SEM) was employed to determine the droplet distribution of the film and surface morphology. The surface roughness remained low over the whole coil current range with values between 0.2 μm at 100 A and 0.8 μm at 200 A.