钛酸锶钡/硅纳米孔柱阵列复合薄膜的制备及电学性能

The preparation and electrical properties of barium strontium titanate/silicon nanoporous pillar array composite thin films

采用溶胶-凝胶技术制备了钛酸锶钡薄膜(Ba0.7Sr0.3TiO3,BST)/硅纳米孔柱阵列(Si-NPA)复合薄膜,扫描电镜显示BST均匀地覆盖在Si-NPA衬底的柱状表面,X射线衍射研究表明BST在600℃及以上退火温度下可形成钙钛矿相结构。剩余极化强度(Pr)和矫顽场(Ec)随着温度的升高而增大,在800℃退火温度下分别对应于4.57μC/cm2和7.61kV/mm。机理研究表明,肖特基发射和空间电荷限制电流两种机理共同作用于该薄膜材料的漏电流形成过程。

The barium strontium titanate（Ba0.7Sr0.3TiO3,BST）/silicon nanoporous pillar array（Si-NPA） composite thin films are synthesized by a sol-gel technique.SEM reveals that the BST has uniformly covered the pillar-like surface of the Si-NPA substrate.X-ray diffraction analysis indicates the appearance of perovskite structure of BST when the annealing temperature is higher than 600℃.The remnant polarization（Pr） and coercive field（Ec） values increase with the annealing temperature,with the maxima of 4.57μC/cm2 for Pr and 7.61kV/mm for Ec at 800℃,respectively.The leakage current formation mechanism of BST thin films resulted from the interaction of the Schottky emission mechanism and the space-charge-limited-current（SCLC） mechanism.