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

摘要

Phase-transition temperature of GeSbTe (GST) chalcogenide film was drastically increased from 159 to 236 ℃ 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.