Crystallization of Ge2Sb2Te5 nanometric phase change material clusters made by gas-phase condensation

International audienceThe crystallization behavior of Ge2Sb2Te5 nanometric clusters was studied using X-ray diffraction with in situannealing. Clusters were made using a sputtering gas-phase condensation source, which allowed for the growth of well-defined, contaminant-free, and isolated clusters. The average size for the clusters is 5.7 ± 1 nm. As-deposited amorphous clusters crystallize in the fcc cubic phase at 180 °C, while for thin films, the phase change temperature is 155 °C. This observation illustrates the scalability of the Ge2Sb2Te5phase change from the amorphous to the cubic state in three-dimensionally confined systems in this size range

The effect of Ta interface on the crystallization of amorphous phase change material thin films

International audienceThe crystallization of amorphous GeTe and Ge2Sb2Te5 phase change material films, with thickness between 10 and 100 nm, sandwiched between either Ta or SiO2 layers, was investigated by optical reflectivity. Ta cladding layers were found to increase the crystallization temperature, even for films as thick as 100 nm. X-Ray diffraction investigations of crystallized GeTe films showed a very weak texture in Ta cladded films, in contrast with the strong texture observed for SiO2 cladding layers. This study shows that crystallization mechanism of phase change materials can be highly impacted by interface effects, even for relatively thick films. (C) 2014 AIP Publishing LLC

Impact of WSix Metal Gate Stoichiometry on Fully Depleted SOI MOSFETs Electrical Properties

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