HIGH-RESOLUTION AND CONVENTIONAL TRANSMISSION ELECTRON-MICROSCOPY IN THE CHARACTERIZATION OF THIN-FILMS AND INTERFACES INVOLVING II-VI-MATERIALS

The use of high resolution transmission electron microscopy (HRTEM) in the characterisation of semiconductor interfaces is reviewed. The importance of employing particular imaging conditions in the electron microscope to reveal and characterise structural and compositional features will be highlighted. The application of these combined experimental and theoretical approaches to the elucidation of specific problems in the II-VI field will then be discussed. We show how the presence of compound formation, e.g. Ga2Se3, at interfaces between ZnSe epitaxial layers prepared by metalorganic vapour phase epitaxy (MOVPE) and single crystal GaAs substrates has been confirmed by employing [100] projection instead of the more usual [110] direction for cross-sectional studies. Also, we show how conventional TEM has been employed to study the relation between structural defects in ZnSe films and specific low temperature photoluminescence peaks such as Y0. We also show recent results on growth procedures of II-VI multilayer structures using HRTEM as the main characterisation tool.