Effect of substrate temperature on microstructures and dielectric properties of compositionally graded BST thin films

• Published in: Transactions of Nonferrous Metals Society of China Vol. 16; no. B01; pp. 126 - 129
• Main Author: 张柏顺 郭涛 章天金 王今朝 全祖赐
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2006; School of Physics and Electronic Technology, Hubei University, Wuhan 430062, China
• Subjects: dielectric properties; graded Ba 1- xSr xTiO 3 thin films; microstructures; substrate temperature; 介电性质; 成分梯度BST薄膜; 显微结构; 衬底温度; microstructures; graded Ba 1- x Sr x TiO 3 thin films; substrate temperature; dielectric properties; graded Ba1-xSrxTiO3 thin films
• ISSN: 1003-6326
• DOI: 10.1016/S1003-6326(06)60159-3

Compositionally graded Ba1-xSrxTiO3 （BST） （x = 0-0.3） thin films were prepared on Pt/Ti/SiO2/Si substrate at different substrate temperatures ranging from 550 ℃ to 650 ℃ by radio-frequency （rf） magnetron sputtering. The effect of substrate temperature on the preferential orientation, microstructures and dielectric properties of compositionally graded BST thin films was investigated by X-ray diffraction, scanning electron microscopy and dielectric frequency spectra, respectively. As the temperature increases, the preferential orientation evolves in the order： randomly orientation→ （111） → highly oriented （111） （α（111）= 60.2%）. The surface roughness of the graded BST thin films varies with the substrate temperatures. No visible internal interface in the compositionally graded thin films can be observed in the cross-sectional SEM images. The graded BST thin films deposited at 650 ℃ possess the highest dielectric constant and dielectric loss, which are 408 and 0.013, respectively.