ION-BEAM DEPOSITION OF A-C-H ON NIOBIUM AND TUNGSTEN - IN-SITU INVESTIGATIONS USING PHOTOELECTRON-SPECTROSCOPY

a-C:H films have been deposited on tungsten and niobium by means of io n beam deposition, using methane as process gas. Step-by-step depositi ons have been performed in a similar manner on both substrates, accomp anied by in situ photoemission measurement cycles. Prior to the film d eposition, the adsorption of methane on tungsten was investigated, rev ealing a chemisorbed carbon layer, which contains some oxygen contamin ations. In both systems, the film deposition led to the formation of a reactive interface, consisting of a carbidic phase. However, the adhe sion properties of both systems differed remarkably. Comparisons conce rning the interface thickness and the adhesion properties are made bet ween the two systems. Furthermore, these results are compared to resul ts obtained in an earlier investigation of polystyrene deposited on ni obium.