MICROSTRUCTURAL MODIFICATION IN CO CU MULTILAYERS PREPARED BY LOW-ENERGY ION-ASSISTED DEPOSITION/

The microstructure of Co/Cu multilayers deposited by low energy ion-as sisted deposition was investigated. The samples studied were grown by unbalanced magnetron sputtering with and without an applied d.c. subst rate bias of -50 V. Specular and off-specular X-ray reflectivity measu rements were performed on the samples and revealed the presence of rou ghness at the interfaces that was partially correlated throughout the film. The effect of applying a -50 V bias was to suppress the correlat ion of the lower frequency roughness and to slightly reduce the bilaye r period of the multilayer. The differences between the samples are di scussed in terms of possible ion bombardment induced smoothing of the layers and densification of the microstructure. (C) 1998 Elsevier Scie nce S.A.