Scanning tunneling microscopy study of the initial reaction of SiH2Cl2 molecules with the Si(111)-7×7 surface

The initial stage of the reaction of dichlorosilane (SiH2Cl2) with the Si(111)-(7×7) surface under exposure below 1 L is investigated using a scanning tunneling microscope (STM). We found that corner adatoms are preferentially reacted over the center adatoms at the very beginning of exposure. The initial reaction process of SiH2Cl2 with Si(111)-(7×7) surface is discussed. It is suggested that the preferential reactivity of a corner-hole atom is reduced as the exposure increases, which may give rise to reacted rest atoms.