Bi_2VO_(5.5)铁电薄膜的制备及电学性质研究

PREPARATION AND ELECTRICAL PROPERTIES OF Bi_2VO_(5.5) FERROELECTRIC THIN FILM

利用溶胶凝胶法在n-Si(100)衬底上成功制备了钒酸铋(Bi2VO5.5)铁电薄膜.利用X射线衍射和原子力显微镜对薄膜的微结构进行了分析,结果表明,Bi2VO5.5薄膜与n-Si衬底有着良好的晶格匹配并表现出高度的c轴择优取向,晶粒大小均匀.对薄膜电学性质的研究表明,Bi2VO5.5薄膜具有良好的C-V特性,在±4V偏压下,存储窗大于0.4V.当外加偏压为3.2V时,漏电流密度为5×10-8Acm-2.1kHz下介电常数和介电损耗分别为95和0.22.这些结果说明,Bi2VO5.5在铁电存储器方面具有较大的应用前景.

Ferroelectric bismuth vanadate （B2VO5.5 ）thin films were successfully fabricated on n-type Si （100） substrate by sol-gel method. The microstructures of the films were investigated by x-ray diffraction and atomic force microscopy. The results indicate that B2VO5.5 thin films show a good match with the n-Si substrate and a high c-axis preferred orientation with a uniform grain distribution. The investigation on the electrical properties of B2VO5.5 thin films indicates that B2VO5.5 thin films show good capacitance-voltage characteristics, and the memory window is larger than 0.4V when the gate voltage is ±4V. The leakage current density is about 5 × 10^ -8 Acm^-2 when the applied voltage is 3.2V. The dielectric constant and dielectric loss measured at 1 kHz are 95 and 0.22, respectively. All the results indicate that Bi2VO5.5 thin films have potential applications in ferroelectrie memory devices.