STRUCTURE AND GROWTH-MORPHOLOGY OF RF-SPUTTERED SUPERTHIN NIOBIUM FILMS

Superthin niobium films of 3 to 35 angstrom thickness prepared by radi o-frequency sputtering have been studied by modern X-ray methods, such as reflectometry, fluorescence analysis and grazing beam structure an alysis. It has been shown that the films were polycrystalline and cons isted of several layers of niobium oxides and solid solution Nb-O. Two simple models were used to describe early stages of film growth. In t he stage of island growth the complete oxidation of Nb to Nb2O5 is ine vitable. Beginning from effective thickness approximately 5 angstrom t he deposited film becomes continuous, and further, layer-by-layer grow th takes place.