Modeling of texture evolution in copper interconnects annealed in trenches

A model for annealing-induced texture evolution in copper damascene interconnects is presented, accounting for the effects of surface energy and mechanical anisotropies. The model provides predictions of energy minimizing textures which should be favored during grain structure evolution, as a function of the geometry and thermal history of the interconnects. Under the assumptions of the model, lines in which the texture evolves under relatively low strain conditions will develop surface energy minimizing textures. For wide lines this leads to (111) texture, and for narrow lines this leads to (110) texture.