Relative activation energy for laser-induced crystallization of phase change materials

The relative activation energy (E _a ^∗ ) derived from a pulsed laser-induced crystallization of phase change materials (PCMs) was suggested as a useful quantitative parameter to represent the practical switching speed, energy consumption, and storage reliability of phase change random access memory (PRAM). We employed the time-for-constant-fraction technique using the reflectivity change of PCMs and the irradiated laser power/pulse width. Using the suggested method, the E _a ^∗ values for the Ge ₂ Sb ₂ Te ₅ (GST), Bi-doped GST (5.9 at%), and Sn-doped GST (17.7 at%) films were determined to be 6.34 × 10 ^-9 , 4.56 × 10 ^-9 , and 3.77 × 10 ^-9 J, respectively, which reflected their expected device performances of PRAM.