Calculated energetics for adsorption and desorption steps during etching of Si(110) surface by Cl

Energetics and the configurational aspects related to the adsorption of Cl on the (110) index plane of Si and the subsequent desorption of SiClchi spe cies from the surface (leading to etching) were investigated. Calculations were conducted for varying surface Cl concentrations. First and second chlo rination steps for surface Si atoms were analyzed and the role played by su rface vacancies was investigated. On the Si(110) surface, steric effects co ming from repulsive forces among the adsorbed Cl atoms, were found to be qu ite significant. Results indicate that the second chlorination step which l eads to the formation of attached SiCl2 species, is very important in the o verall eching process. (C) 2001 American Vacuum Society.