Deposition rate and thickness uniformity of thin films deposited by a pulsed cathodic arc process

The deposition rate and the film thickness uniformity in a vacuum arc deposition process were investigated with respect to dependence on static and dynamic arc current parameters. Measurements were based on the ion current density. The known relations between the investigated process parameters were verified for the d.c. arc process and served as a reference. In the modified pulsed arc process a considerably increased ion current density was measured (up to 1.2 mA A−1 cm−2 during a 500-A pulse). The angular distribution changed in dependence on maximum pulse current especially and could be measured to be cos3ϕ for Ip=150 A to cos7ϕ for Ip=500 A. This results in very high deposition rates in the central region of the substrate and in changes of the film thickness uniformity. A maximum increase of the deposition rate by a factor 3 (perpendicular to the cathode) was measured. Only in a smaller sector the distribution of the film thickness can be approximated by a cosine function (with exponent n up to 27).