Chemical sputtering of Si related to roughness formation of a Cl-passivated Si surface

Chemical sputtering of Si in a chlorine environment has been examined with molecular dynamics simulations. It is found that chemical sputtering correlates with the roughness formation of Cl-passivated Si surfaces during low-energy ion bombardment. The chlorine passivation of the Si surface prevents the flattening of the surface due to the high activation barrier for surface diffusion. The rough surface contains reactive intermediates that can be desorbed into the gas phase when, after an ion impact, the region has a large energy content. The observed products and the increase of the sputtering yield are in agreement with experimental observations.