Investigation of plasma in hot cathode ion plating

Plasma parameters, especially the potential distribution, determine the whole plating process and the properties of deposited layers. This is particularly true in the systems in which the plasma column is the source of electrons heating the material to be evaporated and simultaneously supplies the ions bombarding the substrate. In the case of an unbiased substrate the energy of the impinging ions is determined by the potential difference between plasma and substrate. Because the properties of deposited layer (adhesion, structure and density) depend on the ion energy, the plasma parameters control the whole process. The plasma column was investigated using the Langmuir probe. The paper describes the measuring system, the investigated plasma device and the results. potential distribution was investigated as a function of electrical parameters of the plasma source. The probe characteristics have been measured in various process conditions and from these results the electron temperature, carrier density and plasma potential have been calculated. (author)