| 초록 |
Surface chemical reactions, such as adsorption of organometallic precursors and exchange of ligands with the surface moieties and counter-reactants, are the key steps that determine the reactivity and the material quality of the resulting thin films for many vacuum deposition processes such as atomic layer deposition (ALD) and molecular layer deposition (MLD). Therefore, it is desirable to understand the mechanism and energetics of these chemical reactions at molecular level in order to properly utilize and design the reactants and processes. Quantum chemical methods such as density functional theory (DFT) calculations often successfully provide crucial analysis on the reaction mechanism and related thermodynamic and kinetic information of such surface reactions. In this work, recent examples of applications of DFT calculations on the surface reactions during ALD and MLD processes are presented. Modeling the surface moieties with functional groups of oxides, metals, organics, and organic-inorganic hybrids using small clusters show reasonable agreement with experimental data when available. The effects of counter-reactants on the deposition chemistry is also discussed through analysis of an exemplar reaction of alumina ALD. |
