Atom Manipulation Using Atomic Force Microscopy at Room Temperature

Atomic force microscopy (AFM) has demonstrated its capabilities as a nanotechnology tool. These capabilities include imaging/characterizing individual atoms on various surfaces and manipulating atoms and molecules. Here, we report how atom manipulation works on a well-known semiconducting surface, Si(111)-(7 x 7). To quantify the stochastic behavior of atom manipulation at room temperature (RT), atom hopping probabilities with various tip-surface distances are derived. The different hopping processes of Si adatoms have different tendencies in the probability plots. More remarkably, the ability of atom manipulation strongly depends on the AFM tip used. Tips can be characterized by their interaction force with surface Si adatoms. Force spectroscopic measurements combined with atom manipulation clarified that the ability to manipulate atoms is correlated with maximum attractive chemical bonding force with surface Si adatoms. Knowing the degree of chemical reactivity on the tip apex used for manipulation is key to enhancing the efficiency of the manipulation process occurring on semiconductor surfaces.