Interdiffusion and barrier layer formation in thermally evaporated Mn/Cu heterostructures on $SiO2$ substrates

Mn/Cu heterostructures thermally evaporated onto $SiO2$ and, subsequently, annealed were investigated by transmission electron microscopy related techniques in order to study the diffusion interactions which lead to barrier layer formation. Energy dispersive x-ray spectroscopy and electron energy loss spectroscopy provide evidence for the interdiffusion between the Mn and Cu layers following a $450°C$ anneal, where the Mn diffuses toward the surface of the structure, while Cu diffuses toward the $Mn/SiO2$ but does not propagate into the dielectric. The chemical composition of the 2–3 nm interfacial layer is primarily a mixture of $+2$ and $+3$ Mn valences, in good agreement with previously reported results.