Atomic-scale modification of the AlCl3-adsorbed Si(111)-7 × 7 surface

Atomic-scale modification of the AlCl3-adsorbed Si(111)-7 × 7 surface is demonstrated through an electric-field induced reaction of adsorbed molecules with the use of scanning tunneling microscopy (STM). An Al2Cl6 molecule dissociatively adsorbs onto a Si(111)-7 × 7 surface at room temperature, resulting in the adsorption of Cl atoms and AlClx fragments. Atomic-scale modification around the adsorption sites is induced by applying a voltage pulse to the surface. A single Cl atom is extracted for both sample bias polarities, and the extraction probability for a positive bias is higher than that for a negative bias. It is also found that the extraction probability increases with gap conductance. Manipulation and dissociation of the adsorbed molecules are also demonstrated.