The Mechanism of Explosive (Shock) Crystallization in Amorphous Films

Abstract

A thermodynamic and kinetic discussion is presented of the experimental data on accelerated crystallization in amorphous films of germanium, silicon, and silicon dioxide occurring on local pulsed heating, shock, or cleavage at speeds up to 102 cm/sec. Energy diagrams have been constructed for crystallization as a self-maintaining shock process via the solid phase or as an explosive one via the liquid as a result of the release of latent heat of crystallization. The conditions for accelerated crystallization are evaluated in relation to the external and internal energy, the temperature, and the effects on the film structure. There is a study of the accelerated-crystallization kinetics, and a method is devised for estimating the crystallite formation time and size from the change in the relative heat loss with time. Crystallization parameters have been calculated for silicon-silicon dioxide, silicon dioxide-silicon, and silicon-silicon structures as affected by the thickness of the film and substrate, the thermal conductivity, and the initial temperature. These parameters agree with experiment.