Thin Solid Films, Vol.370, No.1-2, 232-237, 2000
A unified theoretical model for tensile and compressive residual film stress
A relative simple model is elaborated for the overall behaviour of thr residual stress in a coating layer, grown under continuous bombarding of energetic particles. It concentrates on the transition From tensile to compressive stress under increasing energetic particle flux, a phenomenon frequently observed in experiments. The energy density E in the film is written as a sum of an elastic deformation contribution, and a contribution due to depletion zones between the growing columns. Minimization of E leads to the value of the lateral stress in the film. It is found that the film stress shows a characteristic behaviour on the ratio J(ion)/J(at) (ion to atom flux ratio). Generally, for increasing J(ion)/J(at) the stress will first attain a maximum tensile value, and then will change from tensile to compressive values. Further we find that the maximum tensile stress and the tensile/compressive transition occur at lower J(ion)/J(at) ratios for higher energies of the incoming Energetic particles. These findings agree with a number of experimental results.