Crystallization behaviors of an amorphous Ge2Sb 2Te5 thin film were investigated by in situ measurements of electrical resistivity Rel and optical reflectivity Rop and by transmission electron microscopy during isothermal annealing and continuous heating. Rop increased first and then Rel decreased during the initial stage of crystallization for both annealing conditions due to the electrical percolation of heterogeneous crystallization at the film surface. The two-step decrease in Rel during continuous heating, unlike the monotonous decrease in Rel during isothermal annealing, was induced by the percolation phenomenon via homogeneous crystallization inside the film. The effective activation energy for homogeneous crystallization was 4.30 eV.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)