Effects of substrate orientation and rotation on internal stresses in sputtered metal films

Abstract
This paper reports the influence of substrate orientation and rotation on internal stresses in sputtered films of Cr, Mo, Ta, and 304 stainless steel (SS). The sample films were prepared by magnetron sputtering from cylindrical cathodes under conditions (0.13 Pa argon; deposition rate ∠0.4 nm s−1) known to yield compressive stresses at normal incidence with minimal heating of the deposits. The effects of fixed, oblique incidence are found to fall into three regions. At near-normal incidence little effect is observed. The width of this region is much greater for Ta and SS (±45°) than for Cr and Mo (±5°, ±20°). Beyond the first region the stresses change rapidly with increasing angle, becoming sharply tensile in Cr and SS, while in Mo and Ta they remain compressive but become small. In the third, high-angle region the stresses diminish gradually toward zero. The stress dependence on angle of incidence is similar to a dependence on working gas pressure that was observed in previous studies. Stresses in samples rotated continuously through all angles of incidence were always more tensile than the appropriate average of the static results would indicate. Data are also given for the effects of oblique deposition and rotation on electrical resistivity, optical reflectance, and gas incorporation in the deposited metals.