Characterizations and thermal stability improvement of phase-change memory device containing Ce-doped GeSbTe films

Abstract

Phase-transition temperature of GeSbTe (GST) chalcogenide film was drastically increased from 159 to 236 degrees C by cerium (Ce) doping (up to 8.6 at.%) without altering the resistivity property of GST. Grain refinement via the solid-solution mechanism and the amplification of p-type semiconducting behavior in Ce-doped GST were observed. They were correlated with the enhancement of thermal stability and data retention property of GST as revealed by exothermal and isothermal analyses. Phase-change memory (PCM) device characterized at various temperatures revealed an effective thermal stability improvement on the threshold voltage of PCM device by Ce doping. (c) 2011 Elsevier B.V. All rights reserved.