FORMATION OF IRON FILM BY ION-BEAM DEPOSITION

A low-energy, mass-separated ion beam deposition (IBD) system was developed to investigate fundamental ion-solid interactions which play major roles in thermal non-equilibrium ion-assisted film growth. Using the system, high purity and highly corrosion resistant iron films were formed on silicon substrates at room temperature with ion energies of 50 and 100 eV. The reason why the IBD Fe films had such a high corrosion resistance compared with other high purity Fe metals and stainless steel is discussed from the viewpoint of ion-solid interactions. There is a purification effect due to mass separation and also enhanced surface atom migration due to low energy ion bombardment which seem to be responsible for the formation of a stable surface iron oxide layer, which contributes to the high corrosion resistance of the IBD Fe films.