Growth of highly oriented CoCrTa films by inductively coupled plasma-assisted sputtering

Inductively coupled plasma (ICP)-assisted sputtering using an internal coil was applied to the deposition of ferromagnetic Co-based alloy (CoCrTa) films intended for magnetic recording media. The growth of highly oriented crystalline Co films on both low-temperature Si and glass substrates was achieved. Pole figure measurements indicated the growth of face-centered cubic Co with a (111) plane parallel to the substrate, while a hexagonal close-packed crystalline film with c-axis perpendicular to the glass substrate was obtained by adjusting the rf power applied to the inserted coil and the substrate temperature. In the ICP-assisted sputtering at a coil rf power of 120 W, the deposition rate at a pressure of 1.3 Pa was more than two times higher than that of conventional sputtering at the same target rf power of 150W. The deposition performance responsible for highly oriented crystalline growth and higher deposition rate at low pressures was discussed in terms of target self-bias voltage and plasma parameters measured using a Langmuir probe. The film properties characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and vibrating sample magnetometer (VSM) were also presented showing the superior capability of ICP-assisted sputtering for ferromagnetic targets.