Molecular dynamics analysis of reflow process of sputtered aluminum films

It is important that aluminum films fill the grooves on silicon substrates if high-density devices are to be produced. In this paper, we calculate the changes in the free-surface profiles of deposited aluminum films in a high-temperature reflow process on flat and grooved substrates using a molecular dynamics simulation. We use an atomic-scale model to analyze the micron-scale flow on the substrates. The relationships between droplet formation and the parameters of initial film-thickness distribution, aluminum film temperature, and bond energy between the aluminum and substrate atoms are also investigated. When the film at the bottom of the groove walls is thick, film breaks are observed at the top of the groove walls and a large volume of the film flows into the bottom of the groove. We also calculate the change in the aluminum-film profiles for a high-temperature sputtering deposition process.