Nitrogen-doped Sb-rich Si-Sb-Te phase-change material for high-performance phase-change memory

The effects of nitrogen doping on the phase-change performance of Sb-rich Si-Sb-Te materials are systemically investigated, focusing on the chemical state and the role of nitrogen upon crystallization. The tendency of N atoms to bond with Si (SiN_x) in the crystalline film is analyzed by X-ray photoelectron spectroscopy. The microstructures of the materials mixed with Sb₂Te crystal grains and amorphous Si/SiN_x regions are elucidated via in situ transmission electron microscopy, from which a percolation behavior is demonstrated to possibly describe the random crystallization feature in the nucleation-dominated nanocomposite material. The phase-change memory cells based on N-doped Sb-rich Si-Sb-Te materials display more stable and reliable electrical performance than the nitrogen-free ones. An endurance characteristic in the magnitude of 10⁷ cycles of the phase-change memory cells is realized with moderate nitrogen addition, meaning that the nitrogen incorporation into Si-Sb-Te material is a suitable method to achieve high-performance phase-change memory for commercial applications.