STM study of Si(111)√3 × √3R30°B surface structure formed by HBO2 irradiation

Abstract With irradiation of HBO 2 molecules onto the Si(111)-7 × 7 surface at ∼750°C, the √3 × √3 structure, where B atoms occupy the T 4 sites, was formed as predicted from previous electron diffraction measurements. In the initial stage, HBO 2 molecules were found to react with the unfolded half-units of the Si(111)-7 × 7 surface. When the √3 × √3 structure was heated at ∼900°C for 5 s, another √3 × √3 structure was formed. Upon comparison between the two structures, the high-temperature phase was attributed to the structure where B atoms occupy the S 5 sites.