Scanning probe microscopy techniques with atomic resolution

Ivan Ošťádal

Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University in Prague,
V Holešovičkách 2, 182 00 Praha 8, Czech Republic

Scanning tunneling microscopy (STM), atomic force microscopy (AFM) and related scanning probe microscopy (SPM) techniques developed during the last two decades are widely used for studying material surfaces. Information on surface structure with atomic resolution provided by imaging in real space considerably helped to elucidate a number of open questions and introduced new concepts into studying surface processes and crystal growth. STM technique (limited on conductive materials) can be modified for tunneling electron spectroscopy and used for investigation of local electron structure at surface. Dynamical measurements – imaging the surface at changing sample temperature or even during deposition of growing material – allow direct studying of phase transitions, behavior of individual atoms at surface diffusion, nucleation and growth. STM installed into ultrahigh vacuum chamber with various deposition and other techniques for surface analysis represents a powerful tool for complex experiments in surface science. AFM is the most used SPM technique especially due to variability of measuring modes, possibility of using various interactions for imaging sample surface and measurement at ambient conditions. Well defined atomically resolved measurements require ultrahigh vacuum conditions. AFM images obtained in this way can be interpreted with the help of theoretical models and chemical resolution is possible.

The contribution is focused on STM and AFM methods with respect of imaging surfaces with atomic resolution. It provides information on conditions and limitations of imaging, a comparison with other techniques and new prospects.