Interface roughness correlation due to changing layer period in Pt/C multilayers

Abstract

Since the morphology in the interface plane and along the growth direction is important for imaging applications, the dependence of this on the layer period has been investigated in Pt/C multilayers with varying period lengths d ranging from 4.60 to 3.53 nm prepared by dc magnetron sputtering under identical deposition conditions. The Pt layer thickness in all the cases was maintained at a nominal value of $\ensuremath{\sim}0.37d,$ and a total of 20 layer periods were deposited in each case. The grazing incidence x-ray scattering technique has been used to study both the specular and diffuse scattering behavior of these multilayer structures. The interface roughness was found to vary from 0.35 to 0.43 nm, and the lateral and longitudinal correlation lengths remain unchanged with a decrease in layer period as seen from the diffuse component of the scattering. However, the atomic ordering in the individual layers studied using high angle x-ray diffraction shows clearly the presence of crystallinity in the Pt layers, independent of the layer period.