Patent ID: 7930113
Filing Date: 2011-04-19
Classification: G01L

Abstract:
1. A computer-implemented method to determine stress in a multi-layer thin film system, the method comprising: for a system comprising a substrate with a plurality of films layered thereon, determining film stresses in the plurality of films, interface shear stresses at a substrate-film interface and film-film interfaces and system curvatures in terms of contributions of misfit strains and thicknesses of the plurality of films; using a relationship between the contributions of the misfit strains and the system curvatures to express the film stresses in the plurality of films and the interface shear stresses at the substrate-film interface and film-film interfaces in terms of the system curvatures and the thicknesses of the plurality of films; and transmitting the film stresses in the plurality of films and the interface shear stresses at the substrate-film interface and film-film interfaces expressed in terms of the system curvatures and the thicknesses of the plurality of films to a computer-readable medium, wherein expressing the film stresses in the plurality of films and the interface shear stresses at the substrate-film interface and film-film interfaces in terms of the system curvatures and the thicknesses of the plurality of films comprises determining a solution for a linear elastic constitutive model developed based on Stoney's formula and determining forces and bending moments in the substrate from the linear elastic constitutive model.