Suppression of Discharge Fluctuation in Vacuum Arc Deposition Apparatus for Producing AlN Film

Abstract

When a conventional vacuum arc deposition apparatus is operated for producing AlN film, which is insulating material, the arc voltage gradually fluctuates and sometimes the arc extinguishes. In this paper, a new device for suppressing the fluctuation is designed and equipped to the conventional apparatus. The device is named Anode-Screen (AS).
Current distribution on the anode surface is measured as a function of axial distance from the cathode, z. It varies with time in the conventional apparatus while it doesn't in the new apparatus equipped with AS. Spectral intensities radiated from A, Al⁺, N₂, and N₂⁺ existing in the arc plasma measured as a function of z. AlN films are produced at the various positions in the apparatus and the thickness is measured. The results show that neither spectral intensity of only Al⁺ nor film thickness is influenced by AS.
The mechanism of fluctuation of the arc ignited in the conventional apparatus and its suppression effect of AS are discussed in terms of AlN film depositing on the anode surface and electron current path flowing into it.