【摘要】 采用磁控溅射法制备不同含量Er掺杂Sb₂Te₃硫系相变存储薄膜,并利用原子力显微镜、X射线衍射仪、X射线光电子能谱仪、分光光度计、红外椭圆偏振仪等对其形貌、结构、电学性能、光学性能等进行表征分析.结果表明:Er掺杂可以有效抑制Sb₂Te₃结晶生长、减小晶粒尺寸,从而显著增加结晶温度、降低电阻漂移系数（从0.015 90降至0.002 41）,提升该相变存储薄膜整体的非晶态热稳定性.此外,随着Er掺杂含量的增加, Sb₂Te₃薄膜的短波截止吸收边出现蓝移,其光学带隙从1.40 e V分别提升至1.76 e V和1.94 e V,同时其红外波段的折射率明显降低. X射线衍射数据证实:Er掺杂会细化晶粒,引起Sb₂Te₃结晶相发生晶格畸变; X射线光电子能谱分析发现:相变性能提升的内在原因是高含量Er掺杂引起高结合能的Er-Te成键,表明Er掺杂有助于提高Sb₂Te₃相变材料在光电存储器件中的数据存储可靠性.这可为相变存储器用于大规模神经形态计算的下一代存算一体技术提供材料支撑.更多还原

【Abstract】 By using magnetron sputtering, we deposited pure and Er doped Sb₂Te₃ chalcogenide phase-change films. The morphologies, structures, electrical and optical properties were examined by the techniques such as atomic force microscopy, X-ray diffractometry（XRD）, X-ray photoelectron spectroscopy（XPS）, spectrophotometry,and infrared ellipsometry. It was found that, Er doping significantly reduces the crystalline grain size of Sb₂Te₃films, which is accompanied by the increases of crystallization temperature and decreases of resistance drift coefficient（0.015 90 to 0.002 41）. It implies Er doping can enhance the overall amorphous thermal stability of Sb₂Te₃ films. Moreover, an increase of Er doping content correlates with a blue shift of short-wave cutoff absorption edge, which results in the elevation of optical band gap from 1.40 eV to 1.76 eV and subsequently to 1.94 eV, and leads to the apparent reduction of refractive index in the infrared spectrum simultaneously. The XRD results support the fact that Er doping can decrease the crystalline grain size and induce the lattice distortion in Sb₂Te₃ crystalline phase. The XPS results demonstrate that the formation of high-binding-energy Er-Te bonds can be found in high Er doped Sb₂Te₃ film but is not detected in low doped film, which is the essence of the thermal stability enhancement for Er doped Sb₂Te₃ film. The above results show the Er doping can improve the data storage reliability of Sb₂Te₃ when used as the phase-change material for photoelectric storage devices, and provide an effective support for the phase-change memory use in large-scale neuromorphic computing.更多还原