ELECTRON-STIMULATED DESORPTION INDUCED BY THE SCANNING TUNNELING MICROSCOPE

The use of the scanning tunneling microscope (STM) as an excitation so urce and a probe of electron stimulated desorption on the atomic scale is reviewed. The case of H desorption from H-terminated Si(001) is ex amined in detail. Experimental results on excitation thresholds, desor ption cross-sections, isotope effects and site-selectivities are prese nted. Evidence for mechanisms involving direct electronic and hot grou nd-state desorption, as well as a novel multiple-vibrational excitatio n mechanism is discussed. Using the latter mechanism, the ultimate res olution limit of selective single atom desorption is achieved. New res ults on desorption from Si dihydride, including a proposed mechanism f or the STM-induced H/Si(001)-3x1 to 2x1 conversion, are presented. Pos sible applications of STM-induced desorption in nanofabrication are co nsidered. (C) 1997 Elsevier Science B.V.