Films which were approximately 100nm-thick were magnetron-deposited and were interposed between 250nm-thick Cu over-layers and Bi2Te3 monocrystalline substrates. The samples were then annealed in vacuum at up to 350C. The performance of the films, as barriers to the in-diffusion of Cu and the out-diffusion of Bi and Te, was evaluated by means of 2MeV 4He back-scattering spectrometry and X-ray diffraction. The Ni-V, Pd and Pt films failed to prevent the interdiffusion of Cu and Bi2Te3 after a few hours at 200C. However, the Ta40Si14N46 barrier was effective after annealing for 50h at 250C, or 1h at 350C.

Films of Ni-7at%V, Pd, Pt and Ta-Si-N as Diffusion Barriers for Copper on Bi2Te3 T.Kacsich, E.Kolawa, J.P.Fleurial, T.Caillat, M.A.Nicolet: Journal of Physics D, 1998, 31[19], 2406-11