Light-induced monolayer modification of chlorinated silicon (111) surfaces studied with a scanning tunneling microscope

• Published in: Surface science Vol. 320; no. 1; pp. 161 - 168
• Main Authors: Shudo, Ken-ichi, Komori, Fumio, Hattori, Ken, Murata, Yoshita
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 1994
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/0039-6028(94)00517-6

Chlorine adsorbed silicon (111) surfaces are studied with a scanning tunneling microscope before and after weak irradiation of ultraviolet, visible and infrared light. We found that di- and tri- chlorinated silicon adatoms are desorbed out after ultraviolet light irradiation, resulting in the formation of a 7×7 surface structure resembling the so-called rest-atom layer. On the other hand, mono-chlorinated silicon adatoms are hardly moved by irradiation. The modification induced by the visible and infrared light are qualitatively similar to that by ultraviolet light. The obtained surfaces are different from the chlorinated surfaces after annealing. These results indicate that the modification is initiated by light-induced electronic excitation at the surface.