钛酸铋薄膜的室温脉冲激光沉积研究

Preparation of Bi 4Ti 3O 12 Thin Films by Pulsed Laser Deposition at Room Temperature

在室温下，采用脉冲激光沉积（ＰＬＤ）技术在７．６２ｃｍＰｔ／Ｔｉ／ＳｉＯ２／Ｓｉ（１００）衬底上制备了钛酸铋（Ｂｉ４Ｔｉ３Ｏ１２）薄膜。Ｂｉ４Ｔｉ３Ｏ１２薄膜的厚度和组分均匀性采用卢瑟福背散射（ＲＢＳ）和扩展电阻技术（ＳＲＰ）来分析、表征；采用Ｘ射线衍射（ＸＲＤ）技术研究了薄膜的退火特性。研究发现单独用常规退火或快速退火热处理的Ｂｉ４Ｔｉ３Ｏ１２薄膜中较容易出现Ｂｉ２Ｔｉ２Ｏ７杂相；而采用常规退火和快速退火相结合的方法，较好地解决了杂相出现的问题，得到相结构和结晶性完好的Ｂｉ４Ｔｉ３Ｏ１２薄膜。透射电子显微镜实验和扩展电阻实验表明，室温下制备的Ｂｉ４Ｔｉ３Ｏ１２薄膜具有良好的表面和界面特性。

Bismuth titanate(Bi 4Ti 3O 12 )thin films were successfully deposited on 7.62 cm Pt/Ti/SiO 2/Si(100) substrates by pulsed laser deposition(PLD) technique at room temperature.The microstructure and crystallinity of the annealed thin films appeared to depend on the annealed temperature and time.The prepared films,which were simply treated with a conventional thermal annealing(CTA) or rapid thermal annealing(RTA)process at a relatively high treatment temperature,exhibited a mixed phase structures consisted of Bi 4Ti 3O 12 and Bi 2Ti 2O 7.In contrast,the films,which were annealed by a combined method with conventional thermal annealing and rapid thermal annealing,showed a pure ferroelectric phase,Bi 4Ti 3O 12 ,and well developed crystallinity.The homogeneties about thickness and stoichiometricity of the prepared Bi 4Ti 3O 12 films were investigated by rutherford backscattering spectrometry(RBS) and spreading resistance probe(SRP) technique.The results of transmission electron microscopy(TEM) and spreading resistance probe(SRP) experiments indicated that the prepared Bi 4Ti 3O 12 thin films had dense,smooth surface morphology and clear,sharp interface as well.