In situTEM study of fractal formation in amorphous Ge/Au bilayer films

Abstract

The kinetic behavior of fractal crystallization in amorphous semiconductor/metal bilayer films has been studied by in situ transmission electron microscopy. The fractal growth process exhibits three stages: rapid growth, steady growth, and slow growth. During the initial rapid growth stage, the fractal crystallization is controlled by both diffusion and reaction processes. With increasing annealing time, fractal growth is obstructed and becomes slower because more and more other fractal patterns approach from the neighborhood. The growth kinetics analysis indicates that both diffusion-limited aggregation and random successive nucleation mechanisms play an important role in fractal crystallization in the amorphous Ge/Au films.