Physical and electrical characterization of Germanium or Tellurium rich GexTe1−x for phase change memories

This paper intends to provide an overview of electrical performances of GexTe1−x with different proportions of Germanium or Tellurium for phase-change memories. Germanium-rich as well as Tellurium-rich phase-change materials have been integrated in simple test devices and programming characteristics, data retention and endurance performances are thoroughly analyzed. Tellurium-rich GeTe alloys exhibit stable programming characteristics that can sustain endurance test up to 1e7 cycles, while Germanium-rich GeTe, probably triggered by Ge segregation, shows an unstable RESET state during repeated write/erase cycles. Data retention on fresh devices is best for out-of-stoichiometry GeTe.