The Roles of Lattice Vibrational Excitation and Product Electronic Excitation in Dissociative Chemisorption on Covalent Solids

该研究项目由分析和表面化学项目支持，关注卤素与硅表面相互作用的动力学。使用分子束散射方法，Ceyer教授和她在麻省理工学院的同事们将测试XeF2（与F原子相比）与硅的高反应性是由于XeF2分子与硅晶格碰撞时发生的大能量转移的假设。这与热力学预期相反。使用一系列不同质量的氟“载流子”，这一假设将被直接验证。此外，通过监测XeF2与硅表面相互作用所产生的电子激发XeF*物质的发射，将探讨抽象化学吸附的详细动力学。含氟物质对硅的蚀刻是硅蚀刻技术的一部分，在电子器件的生产中有广泛的应用。这个研究项目解决了关于表面动力学的基本问题。利用一系列分子束和表面敏感光谱方法，探讨硅晶格的碰撞激发对反应动力学的影响。还将研究含氟分子的抽象解离化学吸附动力学。

This research project, supported by the Analytical and Surface Chemistry Program, is concerned with the dynamics of halogen interactions with silicon surfaces. Using molecular beam scattering methods, Professor Ceyer and her colleagues at MIT will test the hypothesis that the high reactivity of XeF2 (as compared with F atoms) with silicon is due to the large energy transfer that occurs upon collision of the XeF2 molecule with the silicon lattice. This is counter to what would be expected thermodynamically. Using a range of fluorine`carriers` with differing masses, this hypothesis will be directly tested. In addition, the detailed dynamics of abstractive chemisorption will be probed by monitoring emission from electronically excited XeF* species which may result from the interactions of XeF2 with the silicon surface. The etching of silicon by fluorine containing species forms a part of silicon etching technology, with applications in the production of electronic devices. This research project addresses fundamental questions about the dynamics of surfaces. Using a range of molecular beam and surface sensitive spectroscopic methods, the effect of collisional excitation of the silicon lattice on the reaction dynamics will be probed. The dynamics of abstractive dissociative chemisorption of fluorine containing molecules will also be investigated.