Research on Improved Crystallization Properties and Underlying Mechanism of the Sb₂Te₃ Phase-Change Thin Film by Inserting Sn₁₅Sb₈₅ Layers

As a non-volatile semiconductor memory technology, phase-change memory has a wide range of application prospects as a result of the excellent comprehensive performance. In this paper, multilayer thin films based on Sb 2 Te 3 material were designed and prepared by inserting the Sn 15 Sb 85 layer. The thermal and electrical properties of superlattice-like Sb 2 Te 3 /Sn 15 Sb 85 phase-change films can be adjusted by controlling the thickness ratio of Sb 2 Te 3 /Sn 15 Sb 85 . In comparison to the monolayer Sb 2 Te 3 film, the multilayer layer Sb 2 Te 3 /Sn 15 Sb 85 materials have a higher crystallization temperature, larger crystallization activation energy, and longer data lifetime, indicating the great improvement of thermal stability. The changes in the phase structure and vibrational modes of multilayer Sb 2 Te 3 /Sn 15 Sb 85 films were characterized by X-ray diffraction and Raman spectroscopy, respectively. The presence of Sn 15 Sb 85 layers restrains grain growth and refines the grain size. The multilayer Sb 2 Te 3 /Sn 15 Sb 85 films exhibit better surface flatness, smaller surface potential undulation, and lower thickness variations than single-layer Sb 2 Te 3 . Phase-change memory cells based on the [Sb 2 Te 3 (1 nm)/Sn 15 Sb 85 (9 nm)] 5 thin film has a lower threshold voltage (1.9 V) and threshold current (3.1 μA) compared to the Ge 2 Sb 2 Te 5 film. Meanwhile, the electrical heating model of a phase-change memory cell based on a [Sb 2 Te 3 (1 nm)/Sn 15 Sb 85 (9 nm)] 5 multilayer structure was established by multiphysics coupling analysis, proving the great improvement in heat transfer performance and efficiency. The experimental and theoretical studies confirm that the insertion of the Sn 15 Sb 85 layer can significantly improve the crystallization properties of Sb 2 Te 3 films, paving the way for optimizing the phase-change materials by regulating the microstructural parameters.