Laser-irradiation-induced diffusion in metallic multilayers

Thermal stability and intermixing studies are of primary importance for diverse applications of layered structures and multilayers (MLs). Especially if the thickness of layers is in the nm range, MLs are of great interest for diffusion studies because of small diffusion distances and high number of interfaces. In the paper the intermixing measurements with pulsed excimer laser heat processing are discussed. As a representative example the intermixing studies in Co/Ag bilayers and trilayers for giant magnetoresistance structures are reported. The e-beam evaporated samples were heated by XeCl and KrF lasers and they were analyzed by RBS and grazing incidence XRD methods. Diffusion coefficients for different interfaces are characterized by the activation energy of diffusion, being 0.4 eV for a diffusion at solid- solid and 1.5 eV at solid-liquid interfaces, respectively. The effect of back-diffusion was observed in the Co/Ag immiscible combination of elements.