Special kinetics features of scandium antimonide thin films conducive to swiftly embedded phase-change memory applications

Abstract

Embedded phase-change random-access memory (ePCRAM) applications demand superior data retention in amorphous phase-change materials (PCMs). Traditional PCM design strategies have focused on enhancing the thermal stability of the amorphous phase, often at the expense of the crystallization speed. While this approach supports reliable microchip operations, it compromises the ability to achieve rapid responses. To address this limitation, we modified ultrafast-crystallizing Sb thin films by incorporating Sc dopants, achieving the highest 10-year retention temperature (∼175°C) among binary antimonide PCMs while maintaining a sub-10-ns SET operation speed. This reconciliation of two seemingly contradictory properties arises from the unique kinetic features of the 5-nm-thick Sc₁₂Sb₈₈ films, which exhibit an enlarged fragile-to-strong crossover in viscosity at medium supercooled temperature zones and an incompatible sublattice ordering behavior between the Sc and Sb atoms. By tailoring the crystallization kinetics of PCMs through strategic doping and nanoscale confinement, we provide new opportunities for developing robust yet swift ePCRAMs.