PATTERN EVOLUTION OF CRYSTALLINE GE AGGREGATES DURING ANNEALING OF ANAL GE BILAYER FILM DEPOSITED ON A SIO2 SUBSTRATE/

When an Al/Ge bilayer film deposited on a SiO2 substrate is annealed a t 373-398 K, Ge atoms diffuse out from the inner amorphous Ge layer an d spread over the Free surface of the outer Al layer to form crystalli ne Ge aggregates exhibiting complex substructures. Scanning electron m icroscopy observations indicate that the activation energy for the pat tern evolution of Ge aggregates on the free surface because of anneali ng is 1.56 eV which is about half the activation energy for crystalliz ation of amorphous Ge.