Effect of mold geometry on nanoformed aluminum films investigated using molecular dynamics simulations

The nanoimprint lithography (NIL) process of Al films is studied using molecular dynamics simulations based on the many-body tight-binding potential. The effects of the mold geometry, temperature, and imprint velocity are evaluated in terms of atomic trajectories, potential energy, slip vector, and the radial distribution function. The simulation results show that at the initial imprint, dislocations nucleate and propagate on the (1 1 1) close-packed plane (slip plane). Slip planes with different orientations gradually appear with increasing mold displacement due to the dramatic deformation. A discontinuous geometry of the mold enlarges the effect of adhesion, which leads to a filling failure. The potential energy of Al film increases with imprint temperature, and its release is increasingly delayed with increasing imprint velocity. A better structure order is obtained at lower imprint temperatures.