Interface roughness and texture in Co/Cu multilayers with Ti buffer layer

Abstract

In this study, we investigate the effect of Ti buffer layer on surface/interface roughness and texture of the Co/Cu multilayers. The Ti(0, 3nm)/[Co(5nm)/Cu(5nm)]5 multilayers were deposited by direct current magnetron sputtering. Experimental results show that the rough interfaces and coarse three-dimensional island structure present in Co/Cu multilayers, while the interface roughness decreases and smooth surface emerges in Ti/Co/Cu multilayers. Simulaneously, the sharp {111} fiber texture exists in Ti/Co/Cu multilayers, while the Co/Cu multilayers reveal a weak texture. Compared with the Co/Cu multilayers, inserting Ti buffer layer could decrease the interface energy and increase the wettability. In addition, the {111} fiber texture in FCC metal films corresponds to the most densely packed plane and the minimizing surface energy. Accompanied by the process of film nucleation, it could be concluded that the degree of interface roughness is related to the texture intensity in Co/Cu multilayers. The analyses of magnetic properties suggestes that the higher magnetic properties of Ti/Co/Cu multilayers are caused by the smooth interface and sharp {111} fiber texture.