Effect of annealing on layer intermixing in nanoscale Cr/Ti multilayers depending on the period value

The effect of annealing on the intermixing of thin Ti and Cr layers and their crystallinity in multilayer structures was studied using XPS, TEM, XRR and XRD methods. Multilayer structures with varios period values (sum thickness of the Ti and Cr layers) in the range from 1.4 nm to 4.3 nm were considered. The analysis revealed the formation of TiCrx at the interfaces of the layers. The contribution of the formed chromide relative to the base layers increases with decreasing period of the structure. The layers in the structure with thinnest period were found to be X-ray amorphous, while the structure with a thicker period exhibited the appearance of large crystallites of chromium and titanium. Annealing of the multilayer structures induced additional intermixing, leading to an increase in the extension of the chromide regions. Additionally, it resulted in a reduction of internal stresses within the structures. When the multilayer structures were annealed at a temperature of 700 degrees C, complete degradation occurred, with all layers intermixing with each other and with the Si substrate.