Comparative study of crystallization processes in Sb2Te3 films using laser and thermal annealing techniques

Adherent and pin-hole free amorphous Sb₂Te₃ thin films have been obtained by vacuum evaporation at substrate temperatures ≤25 °C. The films have been crystallized by thermal and laser annealing, and the crystallization processes monitored as a function of annealing temperature and laser scan speed. A comparative study of topography reveals disk-shaped crystallized areas in thermal crystallization and dendrite growth in the laser induced process. The crystallized films in both cases contain a single Sb₂Te₃ phase. Activation energy of 2 eV for crystallization, determined using differential scanning calorimetery indicates good room temperature stability of the amorphous states.