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We have investigated the adsorption of 2-Fluoroethanol on the Si(001)2x1 surface and their photo-induced decomposition by using synchrotron radiation photoemission spectroscopy. The results have been obtained at the 7B1 beamline of Pohang accelerator laboratory (PAL) in Korea. We have taken Si 2p, C 1s, O 1s and F 1s core level spectra from 2-Fluoroethanol adsorbed Si surfaces with increasing synchrotron radiation (SR) irradiation. Si 2p core level spectra taken after 2-Fluoroethanol exposures show two new surface components due to FCH2CO-Si and H-Si species. This indicates that 2-Fluoroethanol adsorbs on the Si(001)2x1 surface at room temperature (RT) through the dissociative adsorption of FCH2COH into FCH2CO(ad) and H(ad) without breaking the Si dimers. C 1s core level spectra consist of two components due to -C-F and -C-O groups but only single component is observed in O 1s and F 1s core level spectra. This strongly supports the dissociative adsorption of 2-Fluoroethanol at RT. When the Fluoroethanol adsorbed surface is exposed to SR, F 1s peak and the component due to the -C-F group in C 1s are decreased, while Si 2p and O 1s spectra are unchanged in intensity and spectral shape. These results clearly show that the C-C bonds are cleaved and then the -C-F groups desorb from the surface upon SR irradiation. We have also studied the bond cleavage induced by other sources, such as thermal effect and e-beam irradiation. Contrary to SR irradiation, F 1s peak is not clearly disappeared upon annealing or e-beam irradiation. This suggests that photon irradiation could be useful in removing some species and then making nanopatterns on solid surface. |