Multi-scale modeling and simulation of multi-physics in film delamination

To bridge the different spatial and temporal scales involved in the process of tungsten (W) film delaminating from silicon (Si) substrate, a multi-scale model-based simulation procedure is being proposed. In the proposed procedure, a bifurcation-based decohesion model which represents the link between atomic and continuum levels is first formulated based on continuum mechanics. A molecular dynamics (MD) simulation of W film deposition onto Si is then performed with the proposed W-Si Morse potential. The transition of film residual stress from tension to compression is qualitatively simulated. An MD simulation of W crystal under tensile loading is conducted to establish the multi-scale decohesion-traction relationship, which is then input into the bifurcation-based decohesion model at the micro-scale level with a scaling law to account for the size effect. A multi-scale simulation of film delamination is then performed within the framework of the material point method. The simulated results have provided new insights into the mechanisms of the formation of film residual stress during the deposition process and the subsequent delamination of film.