title: Soft x-ray photoreactions of CF3Cl adsorbed on Si(111)-7x7 studied by continuous-time photon-stimulated desorption spectroscopy near F(1s) edge.
abstract: The continuous-time core-level photon-stimulated desorption (PSD) spectroscopy was employed to monitor the monochromatic soft x-ray-induced reactions of CF3Cl adsorbed on Si(111)-7x7 near the F(1s) edge (681-704 eV). Sequential F+ PSD spectra were measured as a function of photon exposure at the CF3Cl-covered surface (dose=0.3x10(15) molecules/cm2, approximately 0.75 ML). The F+ PSD and total electron yield (TEY) spectra of molecular solid CF3Cl near the F(1s) edge were also measured. Both F+ PSD and TEY spectra show two features at the energy positions of 690.2 and 692.6 eV, and are attributed to the excitations of F(1s) to 11a1[(C-Cl)*] and (8e+12a1)[(C-F)*] antibonding orbitals, respectively. Following Auger decay, two holes are created in the F(2p) lone pair and/or C-F bonding orbitals forming the 2h1e final state which leads to the F+ desorption. This PSD mechanism, which is responsible for the F+ PSD of solid CF3Cl, is employed to interpret the first F+ PSD spectrum in the sequential F+ PSD spectra. The variation of spectrum shapes in the sequential F+ PSD spectra indicates the dissipation of adsorbed CF3Cl molecules and the formation of surface SiF species as a function of photon exposure. From the sequential F+ PSD spectra the photolysis cross section of the adsorbed CF3Cl molecules by photons with varying energy (681-704 eV) is determined to be approximately 1.0x10(-17) cm2.
authors: Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan. crwen@mail.ncku.edu.tw
authors: C-R
authors: CR
authors: Wen
authors: C-Y
authors: CY
authors: Jang
authors: L-C
authors: LC
authors: Chou
authors: J
authors: J
authors: Chen
authors: Y-H
authors: YH
authors: Wu
authors: S-C
authors: SC
authors: Chang
authors: W-C
authors: WC
authors: Tsai
authors: C-C
authors: CC
authors: Liu
authors: S-K
authors: SK
authors: Wang
authors: Y
authors: Y
authors: Shai