Investigation of superthin carbon layers and multilayer carbon structures by X-ray reflectivity measurements.

In situ X-ray monitoring of reflectivity in the short range 0.05-0.3 nm for investigation of thin carbon layers and multilayer carbon structures is proposed. X-ray monitoring is based on periodical alternations of Fresnel's reflectivity when layer thickness increases or decreases. The source of X-rays with wavelength 0.154 MI was located out of working volume of installation and consisted of X-ray tube, monochromator block and collimating system. The objects of in-situ investigations were carbon films obtained by RF-plasma discharge and magnetron methods. Multilayer carbon structures were synthesized by alternating these layers. Density and microroughness of the growing film were determined for every half-wave of reflectivity oscillations that corresponds to averaging by the layer of 1.0 nm thickness. It is shown that X-ray monitoring system permits to control the layers thickness during multilayer structure growth with precision up to 0.1 nm.