Soft Magnetic Properties of Fe-Si-N Thin Films

The crystal structure and magnetic properties of sputter-deposited Fe-Si-N films were investigated. Fe-Si-N films had a single ¿-Fe phase, and with higher N content, two phases, ¿-Fe and ¿´-Fe4N. A coercivity Hc lower than 1 Oe was obtained for single ¿-Fe phase films. The permeability ¿ was found to be strongly related to the substrate temperature Tsub during deposition. For example, deposition at Tsub=230°C gave rise to ¿=3600 at 10 MHz. Such high values were obtained in single ¿-Fe phase films, which consisted of fine crystal grains with a (111) plane orientation. The permeability of films with a high Si concentration was found to have high thermal stability.