Formation and Chemical Selectivity of Partially Ga-Terminated Si(111) Surfaces

Nanoscale stripes of the Si(111)-(7 × 7) structure with atomic accuracy can be formed on the [Formula: see text]-terminated Si(111) surface, by selective thermal desorption of Ga atoms from step edges, when the surface is tilted toward the [Formula: see text] direction. The nanoscale stripes of the 7 × 7 structure can also be formed in expected areas by selective thermal desorption of Ga atoms induced by STM stimulation. A Ga-terminated area is found to be chemically less active for adsorption of oxygen, disilane and antimony molecules which selectively react in the 7 × 7 area. By using the chemical selectivity and the nanoscale 7 × 7 stripe for formation method, a stripe pattern with the antimony-adsorbed 7 × 7 areas and [Formula: see text] areas is produced as a demonstration of nanostructure formation.