Molecular dynamics study of copper trench filling in damascene process

The trench filling of depositing copper atoms on the titanium layer in a damascene process was studied using molecular dynamics simulation with the embedded atom method (EAM) as interaction potential for the present alloy metal system. A three-layer trench model consisting of the barrier, thermal control, and fixed layers was used. The effects of different process parameters on the trench-filling morphologies and microstructures including incident energies of depositing atoms and substrate temperatures were investigated. The present results using invariance-preserving alloy model are discussed in terms of void formation, coverage percentage, and alloy fraction and compared with simple arithmetic average alloy model.