Crystallization behavior of as-deposited, melt quenched, and primed amorphous states of Ge2Sb2.3Te5 films

We compare the crystallization behavior of thin films of Ge2Sb2.3Te5 in various amorphous states, namely, as-deposited, melt-quenched, and primed. These films are embedded in a quadrilayer stack similar in structure to the commercially available phase-change optical disks. This study shows that the melt-quenched amorphous film has a shorter crystallization onset time and a higher crystallization rate in comparison to the as-deposited amorphous film. We also observed that variable priming leads to crystallization behavior falling between that of the as-deposited and melt-quenched states. A qualitative model of the modification in crystallization behavior due to priming is given based on the notion that priming produces crystalline embryos which hastens crystallization process. (C) 2000 American Institute of Physics. [S0021-8979(00)09219-7].