Parallel molecular dynamics simulation on thin-film formation process

摘要

Chemical vapor deposition is regarded as one of the most promising methods of epitaxial growth for materials such as thin films, nanotubes, etc. The properties of such thin films depend on the states of cluster such as initial velocity, size, etc. We developed parallel molecule dynamics using the potential of the embedded atom method (EAM), which can make the scale of the problem larger and calculation more efficient, to further the understanding of the effect of a cluster's state on the properties of thin film. In this simulation, three different cluster sizes of 203, 563, 1563 atoms with different velocities (0, 10, 100, 1000, 3000 m/s) were deposited on a Cu (001) substrate whose temperatures were set between 300 and 1000 K. Within one velocity range, not only the speed of epitaxial growth and adhesion between thin film and substrate were enhanced, but also the degree of epitaxy increased and the shape of thin film became flatter with velocity increasing. Moreover, the epitaxial growth became good as the temperature of substrate was raised within a certain range, and the degree of epitaxy of the small cluster was larger than the larger cluster. The results indicated that the property of thin film could be controlled if the effect of situations of process was made clear.