An explanation of the crystallization of amorphous Ge₂Sb ₂Te₅ films induced by a short Gaussian laser pulse

Three-dimensional finite element method simulation and experimental investigation were employed to study the fast crystallization mechanism of Ge₂Sb₂Te₅ phase-change alloy films induced by a short Gaussian laser pulse. A crystallization mechanism was proposed which took into account the roles of heating and cooling rates on crystallization of the phase-change materials. Microstructure characteristics of crystallization, primarily attributed to inherent material properties and temperature field, were discussed. The present study not only unveils the crystallization mechanism induced by laser radiance but also distinguishes the roles of the ultrahigh heating/cooling rate for the phase transition.