Controllable residual stresses in sputtered nanostructured alpha-tantalum

Nanostructured α-Ta films were sputtered at room temperature in order to synthesize material that had either compressive or tensile stress states (-1500 to 1000 GPa). The films were coated by magnetron sputtering at various pressures using Si substrates with and without an α-Ta underlayer. The roles of the substrate/film interface, underlayer, grain size and film texture were also investigated as a function of sputtering conditions and residual stress.