Resistance drift of metastable amorphous and crystalline fcc GeSbTe memory devices

Helena Silva, Nafisa Noor, Shalini Tripathi, C. Barry Carter

University of Connecticut

Phase change memory is an emerging technology that utilizes the electrical resistivity contrast between the amorphous and crystalline phases of chalcogenide glasses to store data. The most commonly used material for PCM has been GeSbTe (GST), which has metastable amorphous and crystalline fcc phases and a stable crystalline hcp phase [1]. One difficulty with the implementation of PCM is the upward resistance drift of the metastable amorphous and crystalline fcc phases. We are using electrical characterization together with transmission electron microscopy and finite element electrothermal simulations [2] to study the physical mechanisms that give rise to the electrical resistance drift of GST cells.