MedeA®: Atomistic simulations for designing and testing materials for micro/nano electronics systems

Results of atomic-scale simulations are presented including thermal conductivity, elastic moduli, diffusion, and adhesion. This type of simulations is most conveniently performed with the MedeA® computational environment, which comprises experimental structure databases together with building tools to construct models of complex solids, surfaces, and interfaces for both crystalline and amorphous systems. Central to MedeA® are state-of-the-art modules for the automated calculation of thermodynamic, structural, electronic, mechanical, vibrational, and transport properties combined with the corresponding graphical analysis and visualization tools. These capabilities are illustrated for both inorganic and organic materials. For Si-Ge alloys and amorphous-crystalline silicon superlattices we find a drastic reduction of the thermal conductivity compared with bulk crystalline Si. In addition, the Si-Ge alloys reveal a considerable sensitivity of their thermal conductivity to disorder. The second part of this study addresses properties of epoxy resin based thermosets, including their mechanical stiffness, thermal conductivity, and adhesion on alumina. In addition, we present calculated results for oxygen and water diffusivities in cross-linked epoxy systems and discuss factors influencing such diffusivities as, e.g., mass effects or the concentration of residual hydroxyl groups in the polymer.