我們以新竹同步輻射中心之Wide Range SGM光束線輸出光源能量為240 eV的光子照射在吸附於Si(111)-7×7表面上的CF3Cl分子。我們使用能量為240 eV的入射光子，目的是要激發表面吸附物CF3Cl分子之Cl(2p)蕊層(core-level)電子。針對注入量分別為0.3×1015分子／平方公分(～0.75 monolayer)，以及0.8×1015分子／平方公分(～2 monolayer)的情形，量測隨著光子曝露量的增加，光電子能譜的變化情形，來研究表面的光物理與光化學。從量測的一系列光電子能譜中，我們發現不論是次單層或兩層的之CF3Cl分子吸附的Si基材表面，在剛開始照光時，吸附在Si基材表面之CF3Cl分子會光解離(photolysis)，而產生新的化學態SiCl。產生SiCl的機制是入射光子激發CF3Cl分子導致C－Cl斷鍵。所產生的Cl+離子，將因C-Cl鍵結方向指向Si表面而會和Si表面反應形成SiCl。

　　此外，我們利用信號擬合軟體(Peakfit)，對於兩個主要的化學態CF3Cl及SiCl之變化進行信號擬合。而得知CF3Cl分子於光解離過程之光解離截面(photolysis cross section)。

　　In order to study the soft x-ray-induced reactions of CF3Cl adsorbed on a Si(111)-7×7 surface at 30 K, a photon beam of 240-eV was used as a soft x-ray light source for inducing the reactions and also as a probe for studying the chemical states of the chlorine-containing surface species (adsorbed CF3Cl molecules and the produced surface species) in the photoelectron spectroscopy. Sequential Cl(2p) PES spectra were measured as a function of photon exposure at two adsorbate coverages (the first dose =0.3×1015 molecules/cm2, the second dose =0.8×1015 molecules/cm2). For the first and second CF3Cl-dosed surfaces, the sequential Cl(2p) PES spectra show the variation of shapes with photon exposure and indicate the formation of surface SiCl species.

　　On the other hand, it is interesting to estimate the photolysis cross section of the adsorbed CF3Cl irradiated by 240-eV photons from the sequential Cl(2p) PES spectra.

[1]同步加速器光源，行政院同步輻射研究中心，2005.4.
[2]光束線安全審查報告，行政院同步輻射研究中心，1998.12.
[3]L.-C. Chou, C.-R. Wen and J. Chen, Chinese Journal Of Physics.38 ,987(2000).
[4] M. L. Knotek and P. J. Feibelman, Phys. Rev. Lett. 40, 964(1978)。
[5] D. E. Ramaker, "Desorption Induced by Electronic Transition",
edited by N. H. Tolk, M. M. Traum, J. C. Tully, T. E. Madey (Springer, Heidelberg 1983)。
[6] M. L. Knotek, Rep. Prog. Phys. 47,1499 (1984)。
[7] T. E. Madey, D. E. Ramaker, and R. Stockbauer, Annu. Rev. Phys. Chem. 35, 215 (1984)。