STRUCTURE OF THE SILICIDE/Si, SiO₂/Si INTERFACE ANALYSED USING HIGH RESOLUTION TRANSMISSION ELECTRON MICROSCOPY

Abstract
This paper is a kind of over- view of the problems which have to be solved in order to determine an interface structure. The first question is to be able to interpret the micrographs knowing that the dynamical interaction between electron wave and atomic potential is highly dependent on the crystal structure. Differences between centrosymmetric and non-centrosymmetyric crystals are underlined. The example which is treated is ErSi₂, and the ErSi₂/Si interface is analysed. The second problem is the thickness variation at the interface vicinity ; this is shown to imply contrast variations which can be interpreted as the presence of a thin film between the substrate and the over layer. Finally it is shown how high resolution images are a necessary complement to determine microcrystallite structures, when they are too few and small to be analysed using X-Ray diffraction. The example is SiO₂ precipitates grown in amorphous SiO₂ during ultra dry oxidation.