Amorphous metal films by getter sputtering at 25 K

Abstract

The various amorphous films (Ni, Fe, and Au) were deposited by getter sputtering in helium gas with liquid helium circulating through the substrate table. This technique is effective in producing amorphous films as a result of the low deposition temperature and the incorporation of large amounts of helium gas into the film. The amount of helium gas which was determined by three techniques (Rutherford backscattering, mass spectrometry, and annealing in vacuo) ranges between 10 and 46 at.%. The most interesting feature of this new technique is that the amorphous films thus produced are pure in the sense that the amorphous state was achieved only by the incorporation of a noninteracting noble gas. Indeed, upon annealing in vacuo, which drives the helium out of the films, the films regain all the properties (x-ray structure, resistivity, Rutherford-backscattering yield) of the bulk crystalline material.