Melting of crystalline silicon thin films

Melting of crystalline silicon thin films is studied by molecular dynamics (MD) simulations using Stillinger-Weber potential. Models are heated up from a crystalline to a normal liquid state. Temperature dependence of total energy and the Lindemann ratio exhibits a first-order-like behavior of the transition at a melting point. Heat capacity of the system exhibits a single peak at around the melting point. Atomic mechanism of melting is analyzed via monitoring spatio-temporal arrangements of the liquidlike atoms occurred during heating process. We find the formation of a quasi-liquid surface layer containing both solidlike and liquidlike atoms, i.e. at temperature around the melting point (Tm), there is a mixed phase of the solidlike and liquidlike atoms in the surface layer. The mechanism of melting of crystalline silicon is different from that of Lennard-Jones crystals and monatomic glass with free surfaces due to the potentials used in simulation and due to sizes of models.