Peculiarities of the thickness dependence of the superconducting properties of thin Nb films

Abstract In this report we present results of a systematical study of relevant properties of superconducting Nb thin films of thickness from 8 to 200 nm deposited on Si. We have found that a reduction of thickness d below 50 nm leads to a significant decrease of the critical temperature T C and a strong increasing of the residual resistivity in normal state ρ 0 and a strong increase of the Ginzburg–Landau magnetic penetration depth λ GL (0). Taking into account the dependencies of T C and ρ 0 on the thickness of the film, we have obtained good agreement between experimental dependencies of λ GL (0) on d and theoretical estimations in dirty limit for films thinner than 100 nm.