Preparation and characterization of Ge1Sb2Te4 thin films for phase change memory applications

Ge1Sb2Te4 (GST) thin films were prepared from their respective polycrystalline bulk on ITO coated glass substrates by a thermal evaporation technique. Thin films and devices based on GST for phase change Random Access Memory (RAM) applications were studied using temperature dependent film properties. The phase-transformation temperature of the film was evaluated by the temperature dependent resistance measurement studies using a two probe method. Using current voltage (IV) measurements on Al/GST/ITO/Glass devices using current sweep and voltage sweep modes, confirmed the phase change of the material between amorphous to crystalline states. IV characteristics measurements using a current sweeping mode of a PCM cell with a lesser thickness of 100 nm showed a large snap-back at a low voltage of 1.2 V with a resistance difference of two orders of magnitude. (C) 2014 Elsevier B.V. All rights reserved.