High performance Al3Sc alloy doped Al3Sc–Sb2Te chalcogenides for phase change memory application

Abstract

An Al₃Sc alloy doped Al₃Sc–Sb₂Te chalcogenide was put forward to avoid oxidation of pure Sc and enhance data retention ability. Compared with conventional Ge₂Sb₂Te₅ and Sc-doped Sc_0.2Sb₂Te₃ materials, the Al₃Sc alloy doped Al₃Sc–Sb₂Te chalcogenide has much better thermal stability and data retention. X-ray diffraction and transmission electron microscopy analysis reveal that the structure of Al₃Sc–Sb₂Te has no obvious change compared with Sb₂Te, except for the refined grain size. The Al₃Sc–Sb₂Te based device shows excellent reversible SET–RESET properties with a suitable operation window and a low power consumption of 1.38 × 10⁻¹¹ J. In addition, a good cyclability of 1 × 10⁶ cycles can be obtained with a large resistance ratio of about 10². Our calculations reveal that Al and Sc atoms prefer bonding with Te atoms. These stable local patterns stabilize glassy states and result in high stability.