Adsorption and surface diffusion of oxygen on 3C and 2H-SiC polytypes: Numerical studies

作者：Wang Junjie^*; Zhang Litong; Zeng Qinfeng; Vignoles G L

来源：Mechanical Properties and Performance of Engineering Ceramics and Composites V - 34th International Conference on Advanced Ceramics and Composites, ICACC';10, 2010-01-24 to 2010-01-29.

• Adsorbed oxygen
• Atomic movements
• Coverage ratio
• Density functional theory calculations
• Diffusion paths
• Numerical studies
• Oxygen adatoms
• Oxygen adsorption
• Polytypes
• SiC polytypes
• Single oxygen atom
• Surface sites
• Synergetic effect
• Theoretical chemistry
• Thermostructural composites

Silicon carbide oxidation is an important technological issue either in semiconductor or in thermostructural composite applications. Since this phenomenon starts with oxygen adsorption and surface diffusion, these first steps have been investigated by theoretical chemistry methods, in order to provide some insights. Density Functional Theory (DFT) calculations have been performed for the determination of binding energies of single oxygen atoms on different surface sites (Si-terminated and C-terminated) of cubic (3C) and hexagonal (2H) polytypes of SiC. Atomic movements of adsorbed oxygen have been tracked; diffusion paths and energy barriers have been found. The influence of the oxygen coverage ratio has also been investigated, showing a synergetic effect between oxygen adatoms. Finally, the differences between 3C and the more reactive 2H polytypes are also discussed.

• 出版日期2010
• 单位西北工业大学