Stable structures and electronic states of Si(100)/SiO2 interface have been investigated with the first-principles molecular dynamics method. Quartz, tridymite, and pseudo β-cristobalite are employed as the initial structures of SiO2 at the interface to find the stable ones by structural optimization. It is found that the optimized tridymite-type SiO2 on Si is most stable for a thin (about 7 angstroms) SiO2 layer. For a thicker (about 15 angstroms) layer, however, this structure becomes less stable than the others, and the optimized quartz-type SiO2 structure becomes most stable. Variation of the band gap perpendicular to the interface has also been investigated. In the SiO2 region from the structural interface to a point about 1 angstrom away from it, the band gap remains as narrow as that of silicon. The dramatic change of the band gap takes place in the SiO2 region from about 1 to 4 angstroms away from the interface.
|Number of pages
|Published - 1999 Sept
|Proceedings of the 1999 11th Biennial Conference on Insulating Films on Semiconductors (INFOS'99) - Kloster Banz, Ger
Duration: 1999 Jun 16 → 1999 Jun 19