择优取向MgO缓冲层上制备的硅基Ba0.7Sr0.3TiO3薄膜的结构和性能研究

分别采用sol-gel法和磁控溅射法在Si（001）单晶衬底上制备出（111）和（001）取向的MgO缓冲层薄膜，随后在其上生长Ba_0.7Sr_0.3TiO₃（BST30）铁电薄膜.通过X射线衍射，扫描电子显微镜，原子力显微镜等方法研究了薄膜的微结构.实验结果发现，在较厚的MgO（001）缓冲层上可长出（101）取向的BST30薄膜，而在较薄的MgO（111） 缓冲层上则表现出（101）和（111）取向相互竞争的现象，随着MgO（111）缓冲 关键词： 0.7Sr_0.3TiO₃')" href="#">Ba_0.7Sr_0.3TiO₃ 铁电薄膜 择优取向 sol-gel

Study of structure and properties of Ba0.7Sr0.3TiO3 thin film with prefer-orientated MgO buffer layer on the silicon substrate

The （001） and （111）-oriented MgO buffer layers, on which ferroelectric Ba_0.7Sr_0.3TiO₃（BST30） thin films were prepared subsequently, have been grown on Si （001） single-crystal substrates by sol-gel and magnetron sputtering methods. The microstructure of the thin films was investigated by XRD, AFM and SEM. The results showed that the （101）-prefer-oriented BST30 thin film was obtained on the thicker MgO（001） buffer layer, while only the competition between the （101） and （111） orientations of BST30 can be observed on the thinner MgO（111） buffer layer. With the increasing thickness of MgO（111） buffer layer, the BST30 thin film’s （101） orientation was restrained, whereas the （001） orientation was strengthened. The improved simplex method was utilized to obtain the optical constant （n） and thickness （d） of BST30 thin film and MgO buffer layer. It was also found that the MgO buffer layer can significantly decrease the leakage current and p-n junction effect of BST30 thin film.