Ultrathin TiSiN overcoat protection layer for magnetic media

Abstract

TiSiN ultrathin films (10–50 Å) deposited by reactive magnetron sputtering from TixSiy targets were used as anticorrosion overcoats to protect Co-containing recording media. Films’ growth, structure, composition, resistance against hydrolysis, and anticorrosion performances were studied by spectroscopy (x-ray reflectivity and diffraction, ellipsometry, x-ray photoelectron spectroscopy, Fourier transform infrared reflection–absorption spectroscopy) and simulated by molecular dynamics (using modified Tersoff-type interatomic interactions). TiSiN ultrathin overcoats were found to be dense amorphous oxynitrides containing Ti–O–Si linkages. The conversion of SiNx into SiOx by hydrolysis was prevented by introducing less than 20 at. % of Ti in the films. Thanks to the formation of Ti–O–Si linkages which densify the films and reduce oxygen diffusion, good corrosion protection of the magnetic media was achieved down to 28 Å TiSiN overcoat thickness.