MAGNETIC-PROPERTIES OF FE-N/SI-N MULTILAYER FILMS

Fe-N/Si-N multilayer films have been deposited by an opposed target sputtering apparatus and their structure and magnetic properties were investigated in detail. The multilayer films deposited at a proper nitrogen gas flow rate RN2 have amorphous crystal structure and show excellent soft magnetic properties(coercive force 0.6 Oe). The nitrogen atoms in the Fe-N layer of the film can move easily to the Si-N layer at temperatures below 200°C, if the Si-N layer contains small amount of nitrogen. Furthermore, the interdiffusion of the metal atoms between the Fe-N layer and Si-N layer can occur in the film by annealing at a temperature above 400°C. On the other hand, in the film with nitrogen content above 20 at.%, the nitrogen content in the Fe-N layer changes very little even if the annealing was performed at a temperature above 600°C and its layered structure can be kept stably. These results suggest that Si-N layer is very useful to realize the multilayer films with good thermal stability. Annealing at a temperature above 400 °C can lead to a growth of crystallites in the film,.which deteriorates the soft magnetic properties of these films. © 1990 IEEE