Sputtering of FeCo-B amorphous films with soft magnetic properties

Microstructures, optimum sputtering conditions, and annealing methods were investigated for the purpose of obtaining zero magnetostriction amorphous films with good magnetic softness. Sputtering conditions which suppress formation of columnar structure in films were studied, and films with high density were obtained. The mechanism of columnar structure suppression is discussed. Annealing in an ellipitically rotating field is effective to reduce in-plane anisotropy and Barkhausen-type noise, and to obtain very weak anisotropy for high initial permeability. Some of the samples thus obtained exhibit excellent softness with high initial permeability.