A SLAB-MINDO study of half monolayer and monolayer chemisorption of chlorine on the silicon (001) surface

The chemisorption of chlorine onto the silicon (001) surface is studied at both 0.5 and 1.0 monolayer (ML) coverage using the periodic SLAB-MINDO method. This enables a comprehensive picture of the progressive chemisorption of chlorine onto this surface. The dangling-bond site is determined to be the preferred chemisorption site with the optimum configurations at both 0.5 and 1.0 ML coverage being dangling-bond topologies. It is found that chlorine does not favour subsurface chemisorption nor the shared-dimer or “SiF 2-like” topologies which have been shown to constitute minimum energy structures for fluorine chemisorption on the Si(001)2 × 1 dimerised surface. The results are compared with experiment and other theoretical calculations.