Phase transition kinetics of Sb2Te3 phase change thin films

Phase transition kinetics of Sb2Te3 phase change thin films was investigated in this paper. Sb2Te3 thin films, with thickness of ~100nm, were deposited on K9 glass substrates by DC magnetron sputtering with an alloy target. The crystallization kinetics of Sb2Te3 thin films under isothermal and non-isothermal annealing was analyzed by a home-made in situ temperature-dependent reflectivity tester. From the heating rate dependences of phase transition temperatures, the activation energy was derived. The obtained values of the Avrami indexes indicate that a two dimension growth crystallization mechanism is responsible for the amorphous-crystalline transformation of Sb2Te3 phase change thin films. Although phase transition of Sb2Te3 thin film is confirmed to be continuous in a larger temperature range, but short laser pulse can easily trigger its crystallization process and form clear and confined crystalline marks.