Electron stimulated desorption induced by the scanning tunneling microscope

The use of the scanning tunneling microscope (STM) as an excitation source and a probe of electron stimulated desorption on the atomic scale is reviewed. The case of H desorption from H-terminated Si(001) is examined in detail. Experimental results on excitation thresholds, desorption cross-sections, isotope effects and site-selectivities are presented. Evidence for mechanisms involving direct electronic and hot ground-state desorption, as well as a novel multiple-vibrational excitation mechanism is discussed. Using the latter mechanism, the ultimate resolution limit of selective single atom desorption is achieved. New results on desorption from Si dihydride, including a proposed mechanism for the STM-induced H/Si(001)-3 × 1 to 2 × 1 conversion, are presented. Possible applications of STM-induced desorption in nanofabrication are considered.