Influence of Sputtering Power on Static and Dynamic Magnetic Properties of FeCoN Films

A series of sputtered FeCoN thin films were deposited on Si (100) at different power levels. Films sputtered with 150 W of power exhibited almost in-plane isotropy accompanied with relatively high coercivity of about 50 Oe due to weak perpendicular anisotropy. When the deposition power was 250 W and above, a well-defined in-plane anisotropy emerged with an anisotropy field in the range of 41 to 109 Oe; the coervivity was significantly reduced to a few oersteds. Dynamic magnetic properties were measured with the shorted microstrip transmission-line perturbation method. Controllable and high microwave permeability was obtained for films deposited under high sputtering power. The differences in soft magnetic properties and magnetization dynamics originate from the changes in film composition and residual stress.