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

The kinetic behavior of fractal crystallization in amorphous semiconductor/ metal bilayer films has been studied by in situ transmission electron micro scopy. The fractal growth process exhibits three stages: rapid growth, stea dy growth, and slow growth. During the initial rapid growth stage, the frac tal crystallization is controlled by both diffusion and reaction processes. With increasing annealing time, fractal growth is obstructed and becomes s lower because more and more other fractal patterns approach from the neighb orhood. The growth kinetics analysis indicates that both diffusion-limited aggregation and random successive nucleation mechanisms play an important r ole in fractal crystallization in the amorphous Ge/Au films. [S0163-1829(99 )05031-6].