| 摘要 |
PROBLEM TO BE SOLVED: To significantly improve the insulation resistance and residual polarization of a ferroelectric thin film so that it can be suitably used for a ferroelectric nonvolatile memory element or the like by adding a niobium element to Bi4 Ti3 O12 which constitutes the thin film. SOLUTION: Niobium element is added to a ferroelectric thin film comprising Bi4 Ti3 O12 . The added amt. of the niobium element is 0.2 to 2.5 mol.%, preferably 0.2 to 2.0 mol.%. This ferroelectric thin film can be formed, for example, on a single crystal semiconductor substrate. A ferroelectric element is formed by using this ferroelectric thin film. The ferroelectric thin film can be formed by a sputtering method, laser ablation method, sol-gel method, CVD method or the like on a substrate such as glass, magnesium oxide, or single crystal semiconductor substrate such as silicon and gallium arsenide. For example, Bi2 O3 , TiO2 and NbO5 are mixed in a specified ratio, pulverized and sintered to obtain a sintered body, which is then used as a target for sputtering. |
