Residual Stress Relaxation Induced by Mass Transport Through Interface of the Pd/SrTiO3

Abstract

Metal interconnections having a small cross-section and short length can be subjected to very large mass transport due to the passing of high current densities. As a result, nonlinear diffusion and electromigration effects which may result in device failure and electrical instabilities may be manifested. Various thicknesses of Pd were deposited over SrTiO3 substrate. Residual stress of the deposited film was evaluated by measuring the variation of d-spacing versus sin2ψ through conventional X-ray diffraction method. It has been found that the lattice misfit within film and substrate might be relaxed because of mass transport. Besides, the relation between residual intrinsic stress and oxygen diffusion through deposited film has been expressed. Consequently, appearance of oxide intermediate layer may adjust interfacial characteristics and suppress electrical conductivity by increasing electron scattering through metallic films.

Variation of adhesive force at the interface of Pd and SrTiO3 as a consequence of residual stresses

“…In fact, stress was measured from the slope of the d-spacing versus Sin 2 plot. Afterwards, by considering the measured Poisson´s ratio and elastic module using nanoindentation, residual stress was measured for each Pd film [36]. Underwood [37] showed the effect of residual stresses upon the shift in the shape of the pattern around indentation.…”