Deposition of Thin Metal Films by Means of Arc Discharges under Ultra-High Vacuum Conditions

The paper reports on plasma technology of the production of thin metal layers by means of controlled arc discharges, initiated at ultra-high vacuum (UHV) conditions, i.e. at the background pressure < 10^-8 Pa, and carried out at the operating pressure < 10^-5 Pa. Different UHV arc facilities, which have been designed and operated at IPJ in Swierk, are described. The UHV arc facility equipped with a cylindrical cathode made of a pure niobium (Nb) is applied for the deposition of superconducting Nb layers upon inner surfaces of RF accelerator cavities. The UHV arc device equipped with a truncated-cone cathode made of pure lead (Pb) is used for the formation of photo-cathodes in RF electron guns. Filtering systems, which are used to reduce an amount of metal micro-droplets, are described. Characteristics of the deposited samples show that very pure and smooth metal films of the bulk-like crystalline structure can be produced by means of the described technique.