First-principles calculations for the initial stages of the oxidation on Si(001) surfaces

9 February 2006 (Thu), 3:30 pm - 5:00 pm

6F seminar room, Sengen site

Professor Byung Deok Yu

Department of Physics, University of Seoul

First-principles calculations for the initial stages of the oxidation on Si(001) surfaces

The oxidation of silicon surfaces has attracted much attention as one of the most important processes in current and future Si technology. Particularly, the control of the initial reactions of oxygen to Si surfaces on an atomic scale is an important issue that must be addressed for more stable and better-functioning Si devices.

In this talk, I will present possible initial oxidation structures on flat terraces and at single-layer steps of Si(001) using first-principles total-energy and electronic-structure calculations based on the density-functional theory (DFT). For various oxidation models, the supercell contains a different number of oxygen atoms. Here, I will explain how such a system can be treated in the thermodynamic limit. More detailed information on the electronic properties, such as the local density of states and the scanning tunneling microscopy images, were also determined by the first-principles calculations. The characteristic features that were found therein are discussed and compared to the experimental results. Finally, I will briefly mention our plan to further understand the initial oxidation reactions to Si surfaces.

Dr. Takahisa Ohno (大野隆央)