Electrical Current-Induced Gradual Failure Of Crystalline Ge2sb2te5 For Phase-Change Memory

Electrical failure in crystalline Ge2Sb2Te5 was observed under a direct current bias, which induces a steady degradation of the electrical conductivity. This failure is induced by electromigration because alternating current bias stressing does not trigger this behavior. Nano-scaled voids were generated during current stressing, which explains the gradual increase in the quantitative resistance. Each nano-void previously comprised a molten phase that was induced by localized melting, which produced compositional variation during the solidification process. The phase-change memory can be damaged by electrical stressing in the non-active regions. (C) 2013 AIP Publishing LLC.