Microthermal Stage for Electrothermal Characterization of Phase-Change Memory

This letter describes a novel experimental structure that captures the impact of rapid temperature transients and repetitive cycling on the thermal and electrical properties of Ge₂ Sb₂Te₅ (GST). The microthermal stage dramatically improves the temporal resolution for heating and enables simultaneous thermal and electrical characterizations. Thermal conductivity measurements show phase transitions of GST accompanied by abrupt changes in electrical resistance. Repetitive cycling with durations down to 100 ns produces melt-quenched amorphous GST with the thermal conductivity 40% lower than that of crystalline GST. Recrystallization increases conductivity but not up to the value achieved by long-timescale bulk annealing. This is potentially because the rapidly recrystallized GST contains more disorder near the interface.