Atomically resolved observation of the quenched Si(111) surface with small amplitude dynamic force microscopy

Metastable reconstructed phases and highly disordered regions of the quenched Si(111) 1x1 phase with many silicon clusters were atomically resolved with a constant frequency mode of small amplitude dynamic force microscopy with the second flexural mode of a commercially available dynamic mode cantilever. Improved sensitivity due to the small amplitude dynamic force microscopy could operate at a relatively far distance from the sample surface with a given resolution and enable highly stable imaging with small interaction forces even on the Si(111) 1x1 metastable phases with silicon clusters. All of the individual atoms in the silicon cluster were atomically observed while avoiding deformations of the sample surface and the tip apex. In the case that the interaction forces of the imaging parameters were intently set to be ten times larger than those for stable imaging, arrangements of adatoms could easily be modified by mechanical interaction forces between the tip and the sample surface. The Si(111)-c(2x8) and root 3x root 3 phases of the 1x1 domain were found to have different contact potentials, which make a topographic height gap in a constant frequency shift image. An ultrasmall amplitude operation for the selective detection of electrostatic forces revealed that deviations of the observed height in the 1x1 domain were larger than that in the 7x7 domain due to the contact potential difference of the c(2x8) and root 3x root 3 phases in the atomic level. (c) 2006 American Institute of Physics.