Mixed-mode magnetron and arc deposition of aluminum oxide films

The paper is devoted to the study of the processes of mixed-mode deposition of aluminum oxide films in oxygen and argon mixture. Mixed-mode is a new pulsed thin film deposition technology that combines magnetron sputtering and arc evaporation. The transition of the magnetron discharge to the arc occurs when the discharge current reaches the threshold value, and the arc burning time is controlled by pulse length. The paper describes the experimental equipment and the principles of controlling the parameters of a combined pulse discharge. The results of measuring the ion current density on a substrate and the deposition rate of aluminum oxide films in mixed-modes at different powers of magnetron and arc discharges are presented. Stable initiation of an arc discharge in a pulsed mode with a “poisoned” cathode surface occurs at a cathode current density of 0.4–0.6 A/cm2. With the same average discharge power in mixed-mode, a higher average ion current density on a substrate, higher coating deposition rate and more intensity of plasma radiation are provided, compared with medium-frequency magnetron sputtering.