LabAdviser/314/Microscopy 314-307/SEM/Nova/Transmission Kikuchi diffraction: Difference between revisions

In this section, the in-situ and high temperatures capabilities of TKD for the analysis of metal thin-�films are presented. The model example chosen for this analysis is the solid-state dewetting of Au thin-�films. Solid-state dewetting is a morphological evolution by which an initially continuous thin �film on an inert substrate turns into a discontinuous array of isolated islands, as sketched in Fig. 8.

This happens because thin �films are kinetically frozen unstable structures as a consequence of their formation far from equilibrium. Since the driving force for dewetting is the minimization of the total energy of the free surfaces of the �film and substrate and of the �film-substrate interface, the total free energy associated with the interfaces of a �film is reduced if the �film agglomerates to form islands. Solid-state dewetting occurs at temperatures well below the melting temperature of the �film, so that the material remains in the solid state throughout the process. Since the rate of dewetting is higher in thinner fi�lms, the temperature at which dewetting occurs decreases with decreasing �film thickness.