Pulsed laser cleaning of antimony single crystal <111> surface

The <111> face of an antimony single crystal was irradiated under ultra-high-vacuum conditions by the 193 nm radiation of a high-power excimer laser. The effects of the laser beam on the sample as a function of the light Energy Density (ED) and of the annealing Repetition Number are presented. Surface studies by Auger electron spectroscopy scanning electron microscopy and low energy electron diffraction show that an atomically clean and well ordered surface can be produced by this method. A strong chemical reduction is induced by pulsed laser annealing above 100 to 130 mJ/cm2. Surface analysis shows that, for an ED less than 500 mJ/cm2, the surface evaporates without melting deeper than 200 nm. Evidences for oxide modification and for organic molecule description were observed even after irradiations with an ED as low as 45 mJ/cm2. The surface reduction is described by a thermal model involving surface heating and subsequent evaporation of the oxide layer. The description and diffusion processes may involve both thermal and photolytic mechanisms. (author). 9 refs, 4 figs, 1 tab