Computer simulation of high-resolution transmission electron microscopy images of Si/SiO2 interfaces

Abstract

Cross-sectional high-resolution transmission electron microscopy (HRTEM) images of the crystalline Si/SiO2 interface have been computer simulated on the basis of various interface models in order to facilitate the interpretation of experimental HRTEM images. Continuous random networks of SiO2 have been constructed on crystalline Si substrates with different orientations and surface morphologies using plastic balls and spokes. The distortion energy introduced by artifacts in the model has been relaxed by modifying the atom positions, HRTEM images of the models have been calculated using the multislice dynamical electron scattering method. The apparent shift of the (111)Si/SiO2 interface into the SiO2 region has been observed due to the localization of first Si atoms in SiO2 region. The contrast of the crystalline Si image due to the amorphous SiO2 region in the wedge-shaped bilayer structure of the Si/SiO2 interface has been obscured. The undulated (100)Si/SiO2 interface delineated with {111} facets has given an unexpectedly flat periodic-nonperiodic interface image.