Fluorination of the Dimerized Si(100) Surface Studied by Molecular Dynamics Simulation.

A computer simulation has been carried out illuminate atomic processes in the fluorination of a dimerized Si(100) surface. The molecular dynamics utilizes a combination of two-atom and three-atom interactions to represent the overall system potential energy. Distinctly different outcomes arise from a pair of 130 ps simulations that employ identical initial and boundary conditions. For one of these energy is conserved, the heat released by reaction causes substrate melting, and volatile SiF sub 3 and SiF sub 4 products emerge. The other is nonconservative due to periodic reduction of Si momenta to approximate thermal conduction into a bulk substrate; it just avoids melting, yields a passivated surface with all dangling bonds fluorinated, and fails to produce volatile products.