Structure and growth morphology of RF-sputtered superthin niobium films

Superthin niobium films of 3 to 35 Å thickness prepared by radio‐frequency sputtering have been studied by modern X‐ray methods, such as reflectometry, fluorescence analysis and grazing beam structure analysis. It has been shown that the films were polycrystalline and consisted of several layers of niobium oxides and solid solution NbO. Two simple models were used to describe erly stages of film growth. In the stage of island growth the complete oxidation of Nb to Nb2O5 is inevitable. Beginning from effective thickness ∼ 5 Å the deposited film becomes continuous, and further, layer‐by‐layer growth takes place.