Ferromagnetic resonance of dry etched permalloy thin films

Permalloy thin films deposited by rf magnetron sputtering are ion beam etched or reactive ion etched. Effects of the dry etching on magnetic properties are examined by ferromagnetic resonance and the results are shown as a function of film thickness (etching time). The perpendicular resonance field shifts toward a higher field as ion beam etching proceeds, but it moves to a lower field in the case of reactive ion etching. The effective magnetization of ion beam etched thin films is slightly increased, but the opposite behavior is observed in reactive ion etched thin films. The exchange stiffness constant decreases gradually with ion beam etching whereas a sudden drop to about SxlO'7 erg/cm occurs by reactive ion etching. This result can be explained by surface etching-damaged layer.