Energetics and the configurational aspects related to the adsorption of Cl on the (110) index plane of Si and the subsequent desorption of SiClchi species from the surface (leading to etching) were investigated. Calculations were conducted for varying surface Cl concentrations. First and second chlorination steps for surface Si atoms were analyzed and the role played by surface vacancies was investigated. On the Si(110) surface, steric effects coming from repulsive forces among the adsorbed Cl atoms, were found to be quite significant. Results indicate that the second chlorination step which leads to the formation of attached SiCl2 species, is very important in the overall eching process.