Site-specific force spectroscopy and atom interchange manipulation at room temperature

Abstract

An atomic force microscope (AFM) under noncontact and nearcontact modes operated at room-temperature (RT) is used for investigations of chemical identifications and lateral atom manipulations of selected single atoms on semiconductor surfaces. Noncontact AFM image can give different contrast between intermixed two chemical species. To make clear the mechanism of chemical identification, we investigated atom selective images and site-specific frequency shifts as a function of tip-sample distance in Sb,Sn/Si(111)-(√3 × √3) surface with three different intermixed elements. Recently, using nearcontact AFM, we found a lateral atom-interchange phenomenon at RT and constructed "Atom Inlay", that is, atom letters "Sn" consisted of 19 Sn atoms embedded in Ge(111)-c(2 × 8) substrate. Here, we clarified how to construct "Atom Inlay" in more detail. Further, we observed atom interchange manipulation phenomena even in In/Si(111)-(√3 × √3) and Sb/Si(111)-(7× 7) intermixed systems with not only Si but also In (acceptor element in crystal Si) or Sb (donor element in crystal Si) atoms © 2006 The Surface Science Society of Japan.