Perpendicular anisotropy in granular Co–Zr–O films

Abstract

Soft granular Co–M–O films have promise for application in high-frequency thin-film inductors. But granular Co-based films are often found with perpendicular anisotropy, which can result in stripe domains and poor hysteresis behavior. Film microstructure was analyzed for Co-rich Co–Zr–O granular films with and without stripe-domain behavior. It is suggested that perpendicular anisotropy originates from columnar structure with Co columns perpendicular to film plane. The appearance of columnar structure is determined by sputter pressure and oxygen content.