| As the dimensions of semiconductor devices approach the molecular scale, an atomic level understanding of the surface chemical processes involved in semiconductor fabrication becomes increasingly valuable. Moreover, the incorporation of new inorganic and organic materials into semiconductor devices can be facilitated if a systematic relationship between the electronic structure of semiconductor surfaces and their reactivities toward inorganic and organic compounds can be developed. Therefore, a combination of quantum chemistry and surface analytical techniques is used to investigate the key surface reactions involved in the growth and functionalization of group-IV semiconductor surfaces.; Our calculations on hydrogen desorption and the adsorption of silane and germane on SiGe alloy surfaces have contributed to the elucidation of the elementary surface processes involved in SiGe alloy deposition. The calculated kinetic parameters are incorporated into a model to determine the overall desorption rates of hydrogen from the Si(100)-2 x 1 and Ge(100)-2 x 1 surfaces and to simulate the temperature programmed desorption spectra of hydrogen from the two surfaces. We have also determined the reaction order of hydrogen desorption from the Si(100)-2 x 1 and Ge(100)-2 x 1 surfaces via different proposed mechanisms. Finally, we have simulated hydrogen desorption from SiGe alloy surfaces in order to demonstrate the idea of first-principles based process modeling.; Our studies of the chemistry of organic functional groups on semiconductor surfaces show that the reactivity of semiconductor surfaces can be treated within a localized molecular framework. In particular, the Woodward-Hoffmann rules and the Hammond Postulate can be used to describe the reactions of organic functional groups, such as unsaturated hydrocarbons, amines, and nitriles, on group-IV semiconductor surfaces. The reactivity of the Si(100)-2 x 1 and Ge(100)-2 x 1 surfaces towards amines can be interpreted by a decrease of proton affinity down a periodic group, consistent with the periodic trend found in molecular systems. In addition, our investigation on the chemistry of nitriles on the Si(100)-2 x 1 and Ge(100)-2 x 1 surfaces implies that the Ge(100)-2 x 1 surface is more selective towards the kinetically most favorable product between competing surface reaction pathways. In conclusion, our results show that general chemical principles can be applied to explain the reactivities of group-IV semiconductor surfaces towards inorganic and organic compounds. |
