Continuous-time photon-stimulated desorption spectroscopy studies on soft x-ray-induced reactions of CF 3 Br adsorbed on Si(111)-7×7

• Published in: The Journal of chemical physics 2011-10, Vol.135 (16), p.164704-164704-12
• Main Authors: Tsai, W.-C., Wang, S.-K., He, T.-M., Chou, L.-C., Hsieh, Y.-C., Liao, K.-Y., Chen, H.-C., Wen, C.-R.
• Format: Article
• ISSN: 0021-9606; 1089-7690
• DOI: 10.1063/1.3655563

Continuous-time core-level photon-stimulated desorption (PSD) spectroscopy was used to study the soft x-ray-induced reactions of CF 3 Br molecules adsorbed on Si(111)-7×7 near the Si(2 p ) edge (98-110 eV). The monochromatic synchrotron radiation was employed as a soft x-ray light source in the photon-induced reactions and also as a probe for investigating the produced fluorination states of the bonding surface Si atom in the positive-ion PSD spectroscopy. Several different surface coverages were investigated. The PSD spectra from the low-CF 3 Br-covered surfaces show the production of surface SiF species, while those from the high-CF 3 Br-covered surfaces depict the formation of surface SiF, SiF 2 , and SiF 3 species. The photolysis cross section of the submonolayer CF 3 Br-covered surface is determined as ∼4.3×10 −18 cm 2 . A comparison with the results on CF 3 Cl/Si(111)-7×7 surface is discussed.