脉冲激光沉积技术沉积温度对PZT/LSAT薄膜生长取向的影响

采用固相法分别制备了标准摩尔配比和铅过垦10%的两种靶材.并利用脉冲激光沉积技术(PLD)在镧锶铝钽(LaSrAlTaO3,LSAT)单晶衬底上成功制备了锆钛酸铅(Pb(Zr0.3Ti0.7)O3,PZT)铁电薄膜,在550～750℃沉积温度范围内研究了PZT薄膜的生长取向和铅含最对薄膜生长取向的影响.利用X射线衍射(XRD)仪和原子力显微镜(AFM)表征了薄膜生长取向和表面形貌.XRD测量表明在标准摩尔配比情况下薄膜牛长从550 C近似c轴取向逐渐过渡到750℃近似a轴取向,而在铅过量情况下薄膜生长取向无明显过渡性变化;AFM测量表明PZT薄膜在近似C轴和a轴生长情况下,表面均方根(RMS)粗糙度分别为16.9 nm和13.7 nm,而在混合生长无择优取向的情况下,薄膜表面均方根粗糙度达到68 nm,这可能是两种取向竞争生长的结果.

Influence of Deposition Temperature on Growth Orientation of PZT/LSAT Thin Film

Pb(Zr0.3Ti0.7)O3 (PZT) ferroelectric thin films are grown by pulsed laser deposition (PLD) on LaSrAlTaO3 (LSAT) single crystal substrates from sintered targets of Pb(Zr0.3Ti0.7)O3 and Pb1.1(Zr0.3Ti0.7)O3 (excessive 10%-Pb) with variable temperature of 550～750 ℃, respectively. The pattern observed by X-ray diffraction (XRD) indicates that the orientation of thin film growth transits from approximate c-axis at 550 ℃ to approximate a-axis at 750 ℃ gradually in the no-excessive situation. But in the lead excessive situation, the thin film growth has no obvious transition change. Surface morphology measured by atomic force microscopy (AFM) demonstrates that the root-mean-square (RMS) roughnesses are 16.9 nm and 13.7 nm respectively when the PZT films are grown of approximate c-axis and a-axis. But in the mixed growth orientation, the RMS roughness was about 68 nm due to the competition growth.