CHANGES IN THE COMPOSITION OF SPUTTERED BARIUM FERRITE FILMS AS A RESULT OF SCATTERING DUE TO THE COLLISION OF SPUTTERED PARTICLES AND SPUTTERING GAS

Abstract

In this study, we used computer simulation to investigate changes in the composition of hexagonal barium ferrite films deposited by a facing target sputtering. The iron content in the film increased as the sputtering gas pressure increased and reached a maximum value at a certain gas pressure. These changes in the film composition were explained as follows; sputtered particles scatter when they collide with sputtering gas atoms, and this scattering changes a ratio of the particles reaching the substrate. When the substrate was located to the side of the target as in a facing target sputtering system, this scattering resulted in an increase in the amount of sputtered particles arriving at the substrate, although too much scattering caused the amount to decrease. Since this gas scattering depends significantly on the atomic mass of the sputtered particles, the gas pressure dependence of the amount of the iron atoms arriving differs considerably from that of the amount of barium atoms arriving. This difference leads to the changes in film composition.