BST铁电薄膜的制备及介电性能研究

通过射频磁控溅射法，采用高温溅射、低温溅射高温退火两种不同的工艺制备了钛酸锶钡（BST）薄膜。分析两种不同的工艺对BST薄膜的结构、微观形貌及介电性能的影响。采用X线衍射（XRD）分析了样品的微观结构。采用扫描电镜（SEM）和台阶仪分别测试了样品的微观形貌和表面轮廓。通过能谱分析（EDS）得到了薄膜均一性的情况。最后通过电容 电压（C V）曲线测试得到BST薄膜的介电常数偏压特性。结果表明，与低温溅射高温退火工艺制备的BST 薄膜相比，高温溅射制备的BST薄膜结晶度好，致密性高，表面光滑，薄膜成分分布较均一。因此，采用高温溅射得到的BST薄膜性能较好。在频率300 kHz时，采用高温溅射制备的BST薄膜介电常数为127.5~82.0，可调谐率为23.86%~27.9%。

Preparation and Dielectric Properties of Barium Strontium Titanate(BST) Ferroelectric Thin Films

The BST thin films were prepared by RF magnetron sputtering with two different processes of high temperature sputtering or low temperature sputtering followed by high temperature annealing processes. The effects of the two sputtering processes on the structure, micromorphology and dielectric properties were studied. The crystal structures of BST thin films were characterized by X ray diffraction (XRD). The micromorphology and surface profileof samples were analyzed by scanning electron microscopy (SEM) and surface profilometer. The uniformity of component distribution was showed by energy dispersive spectroscopy (EDS) analysis. Finally, the dielectric constant bias characteristic of the BST film was obtained bymeasuring the capacitance voltage (C V) curve.The results show that, compared with the BST thin film prepared by the low temperature sputtering and high temperature annealing process, the BST thin film prepared by the high temperature sputtering has better crystallinity, higher density, smoother surface, and uniform film composition distribution. Therefore, the BST thin filmsprepared by thehigh temperature sputtering process have better properties.At a frequency of 300 kHz, the dielectric constant of the BST film prepared by high temperature sputtering is 127.5 82.0, and the tunability is 23.86% 27.9%.