掺铝氧化锌薄膜的制备与表征及其与铁电薄膜复合的性能研究

Preparation and Characterization of Al-doped ZnO Films and the Properties of the Composite Films with Ferroelectric Films

采用激光脉冲沉积方法在SiO_2衬底上制备了掺铝氧化锌(AZO)薄膜,X射线衍射分析(XRD)薄膜呈现六角形结构的c轴取向,掺杂后的氧化锌电阻率有明显的下降,并且在可见光区域有很高的透过率,通过椭偏仪测量并拟合了薄膜其它光学性质。用Tauc-Lorentz色散模型表征了不同掺杂浓度的薄膜的折射率和消光系数,随着掺杂浓度升高透射光谱的吸收边向短波长移动,这与所拟合得到的带隙展宽相符。通过采用溶胶凝胶法(Sol-gel)制备了(Pb_(0.9)La_(0.1))(Zr_(0.52)Ti_(0.48))O_3(PLZT)薄膜,并且制备了在PLZT薄膜沉积AZO形成AZO/PLZT的复合薄膜,通过电子显微镜观测了复合薄膜的表面形貌和截面结构,当电场强度为300 k V/cm时,测试复合薄膜铁电性时得到清晰的电滞回线,这为铁电薄膜晶体管的制备提供了可行性。

Al-doped ZnO(AZO)thin films were prepared on SiO 2 substrate by using pulsed laser deposition.X-ray diffraction analysis showed the c-axis orientation in the hexagonal structure.The AZO films exhibited that the resistivity dropped with the increase of doping content,and high transmittance in the visible region.Other optical properties of the films were investigated by spectroscopic ellipsometry.This work adopted Tauc-Lorentz dispersion model to characterize refractive index and extinction coefficient with various Al contents.The absorption edge blue-shifts with increase of Al content could be consistent with widening the band gap from fitting.In this work the(Pb0.9La0.1)(Zr0.52Ti0.48)O3(PLZT)films were prepared by using Sol-gel processing,and AZO/PLZT composite films were fabricated through depositing AZO on PLZT films.Surface morphology and cross sectional structure were assessed by SEM.The composite films showed clear ferroelectric hysteresis loops at electric fields of 300 kV/cm which provide a possibility of fabricating ferroelectric transparent thin-film transistor.