Grazing Incidence X-ray Measurement of Interface Roughness in Sputtered Cu/Co Multilayers

We report grazing incidence X-ray scattering and high angle X-ray diffraction measurements of the structure of sputtered Cu/Co multilayers. Compared with structures grown by molecular beam epitaxy (MBE) the roughness at the Cu/Co interfaces has little conformality and is almost uncorrelated between the bottom and the top. The lateral correlation length is short in comparison with the MBE material. Low energy ion beam etching resulted in significant changes in the giant magnetoresistance, height of the 111 high-angle Bragg peak, and the height of the low angle first order multilayer Bragg peak. It is suggested that interface and crystallographic changes may be coupled and it is not clear at present which is driving the magnetotransport changes.