退火温度对Pt/SrBi2Ta2O9/Bi4Ti3O12/p-Si异质结微观结构与性能的影响

采用sol-gel工艺制备了Pt/SrBi₂Ta₂O₉/Bi₄Ti₃O₁₂/p-Si异质结. 研究了退火温度对异质结微观结构与生长行为、漏电流密度和C-V特性等的影响. 研究表明: 成膜温度较低时,SrBi₂Ta₂O₉、Bi₄Ti₃O₁₂均为多晶薄膜, 但随退火温度升高, Bi₄Ti₃O₁₂薄膜沿c轴择优生长的趋势增强; 经不同退火温度处理的Pt/SrBi₂Ta₂O₉/Bi₄Ti₃O₁₂/p-Si异质结的C-V曲线均呈现顺时针非对称回滞特性, 且回滞窗口随退火温度升高而增大, 经700℃退火处理后异质结的最大回滞窗口达0.78V; 在550～700℃范围内, Pt/SrBi₂Ta₂O₉/Bi₄Ti₃O₁₂/p-Si异质结的漏电流密度先是随退火温度升高缓慢下降, 当退火温度超过650℃后漏电流密度明显增大, 经650℃退火处理的异质结的漏电流密度可达2.54×10^-7A/cm²的最低值.

Effect of Annealing Temperature on Structure and Properties of Pt/SrBi2Ta2O9/Bi4Ti3O12/p-Si Heterostructure

Pt/SrBi₂Ta₂O₉/Bi₄Ti₃O₁₂/p-Si heterostructures were fabricated by sol-gel method. The effects of annealing temperature on microstructure, crystal growth behavior, leakage current density, and C-V characteristics of Pt/SrBi₂Ta₂O₉/Bi₄Ti₃O₁₂/p-Si heterostructure were investigated. The SrBi₂Ta₂O₉/Bi₄Ti₃O₁₂ multilayer thin films annealed at low temperature are polycrystalline, and grow in the preferred c-axis orientation with the increase of annealing temperature. The C-V curves of Pt/SrBi₂Ta₂O₉/Bi₄Ti₃O₁₂/p-Si heterostructure annealed at various temperatures all show a clockwise ferroelectric hysteresis loop. The widths of C-V hysteresis loops of Pt/SrBi₂Ta₂O₉/Bi₄Ti₃O₁₂/p-Si heterostructure increase with the increase of annealing temperature and reach a maximum of 0.78V when the heterostructure is annealed at 700℃. The leakage current density of Pt/SrBi₂Ta₂O₉/Bi₄Ti₃O₁₂/p-Si heterostructure decrease slowly with the increase of annealing temperature from 550℃ to 650℃. However, when the annealing temperature is above 650℃, the leakage current density of Pt/SrBi₂Ta₂O₉/Bi₄Ti₃O₁₂/p-Si heterostructure increase evidently. The lowest leakage current density is 2.54×10^-7A/cm² when Pt/SrBi₂Ta₂O₉/Bi₄Ti₃O₁₂/p-Si heterostructure is annealed at 650℃.