Molecular dynamics simulations of Cl-2(+) impacts onto a chlorinated silicon surface: Energies and angles of the reflected Cl-2 and Cl fragments

We describe the energy and angle distributions of reflected Cl-2 molecules and Cl atom fragments obtained from molecular dynamics (MD) simulations of Cl-2(+) ion impacts onto a chlorinated silicon surface. We simulated Cl-2ion impacts onto a silicon surface with 1 monolayer (ML) of adsorbed Cl ato ms. The ion incident energies E-i were 20, 50, and 100 eV. We varied the io n incident angles theta(i) from 0 degrees to 85 degrees from the surface no rmal. We report the Cl-2 dissociation probability, as well as the scatterin g probabilities for both the Cl-2 molecules and the Cl atom fragments. The effects of E-i and theta(i) on these quantities are discussed. For the 100 eV Cl-2(+) impacts with theta(i) greater than or equal to 75 degrees, we de scribe the distributions of energies E-r. and angles (polar theta(r) and az imuthal phi(r)) for the reflected Cl-2 molecules and Cl atom fragments. In addition, we compare the average energies of the reflected molecules and at oms with the predictions of two simple models based on the binary collision approximation. (C) 1999 American Vacuum Society. [S0734-2101(99)08205-6].