Study of Pt/C x-ray multilayer structure as a function of layer perid using x-ray scattering

Abstract

Pt/C x-ray multilayer, with varying period lengths d, ranging from 4.7 nm to 3.5 nm were made by de magnetron sputtering under identical deposition conditions. The Pt layer thickness in ail the cases was maintained at a nominal value of 0.37d and a total of 20 layer periods were deposited in each case. 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 using x-ray scattering. The grazing incidence x-ray scattering technique has been used to study both the specular and diffuse scattering behaviour of these multilayer structures. The interface roughness was determined from the specular reflectivity measured over a targe momentum transfer range using both 0.154 nm and 0.834 nm wavelength x-rays. The interface roughness was found to vary from similar to 0.32 nm to 0.40 nm with decreasing period. The diffuse component of scattering on the other hand was found to decrease with a decrease in layer period. 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.