The progression of interface structure through sputtered Co/Cu and Co/Pt multilayer films

Abstract

The progression of interface structure through some Co/Cu and Co/Pt multilayer systems, grown on silicon and glass substrates respectively, has been studied using grazing incidence x-ray scattering. Simulations of the data shows that the interface characteristics of the Co/Cu system propagate unchanged with increasing numbers of bilayers. The interface roughness, lateral length scale and fractal dimension remain constant across the series of samples. In contrast, a reduction in the interface conformality between top and bottom surfaces with respect to increasing numbers of bilayers is observed in the Co/Pt system; however the roughness correlation between successive layers is largely maintained. Magnetization data for Co/Cu indicate that the Co layer immediately adjacent to the substrate is magnetically `dead'. This could result from mixing of the cobalt and silicon oxide species at the substrate interface.