Anisotropy induced signal waveform modulation of DC magnetron sputtered thin film disks

Thin films of Co-alloy, intended for use in longitudinal recording, were deposited onto variously prepared substrates by in-line DC magnetron sputtering. An anisotropy induced signal waveform modulation was observed through the use of a disk certifier and verified with vibrating sample magnetometer (VSM) orientation measurements and electron microscopic observation of grain structure. The partial low angle of incidence which can occur in in-line sputtering, the magnetic field generated from the magnetron target, the surface topography of substrates and the sputtering conditions, all affected the extent of preferred anisotropy in the films. By minimizing low angle of incidence sputtering, texturing the substrate surface circumferentially, and adjusting the processing conditions, we can eliminate not only the signal waveform modulation but also enhance the magnetic properties.