Refined thermal stability of Cr/Sc multilayers with Si(Be) barrier layers

Effect of Si and Be barrier layers on the intermixing of thin Cr and Sc layers, as-deposited and after annealing in a wide range of temperatures was considered using X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), X-ray reflectometry (XRR) and grazing-incidence X-ray diffraction (GIXRD). It was established that annealing of a Si/[Cr/Sc]200 system increases mixing. In the sample heated at a temperature of 450°C during 1h as a result of a full intermixing of the Cr and Sc layers a segregation of scandium on the sample surface is traced. The structure becomes textured with Sc [001] preferred orientation perpendicular to the substrate. The insertion of the Be barrier layer in the Si/[Cr/Sc]200 system limits the intermixing between chromium and scandium layers during annealing at temperatures up to 350°C, but full degradation of the structure occurs at 450°C. Be barrier layer in the Cr/Sc system prevents a texturing and grain growth in the system, but does not oppose the crystallization process. A silicon layer inserted between the scandium and chromium layers restricts their intermixing. The multilayer retains an amorphous structure.