Multilayer Ge8Sb92/Ge2Sb2Te5 thin films: unveiling distinct resistance states and enhanced performance for phase change random access memory

Abstract This study investigates the phase-change properties of [Ge 8 Sb 92 (25 nm)-Ge 2 Sb 2 Te 5 (25 nm)] 1 multilayer thin films, elucidating three distinct resistance states originating from two structural transitions: initial Sb precipitation and Ge 2 Sb 2 Te 5 -FCC crystallization, followed by Ge 2 Sb 2 Te 5 -FCC to Ge 2 Sb 2 Te 5 -HEX transformation with additional Sb precipitation. The phase transitions induce two abrupt changes in resistance at temperatures of 169.8 °C and 197.7 °C, respectively, with corresponding data retention temperatures of 97 °C and 129 °C, indicating robust thermal stability. The [Ge 8 Sb 92 (25 nm)-Ge 2 Sb 2 Te 5 (25 nm)] 1 -based phase change random access memory (PCRAM) device demonstrates reversible switching characteristics and multi-level storage capabilities within 20 ns, showcasing enhanced phase-change speed and storage density. In summary, [Ge 8 Sb 92 (25 nm)-Ge 2 Sb 2 Te 5 (25 nm)] 1 demonstrates enhanced thermal stability, swift phase transition, and increased storage density relative to conventional Ge 2 Sb 2 Te 5 , establishing it as a promising new phase-change material for PCRAM applications.