Chemical structures of the SiO2/Si interface

As a result of considerable progress in microfabrication technology for ultra-large scale integration (ULSI), it has become necessary to control oxide formation on an atomic scale in order to produce defect-free SiO2/Si interfaces. However, the possibility of forming an atomically flat interface by oxidizing an atomically flat silicon surface without introducing structural defects is not yet clarified. In this article the present understanding of chemical structures of SiO2/Si interfaces and initial stage of oxidation of silicon surfaces are reviewed.