摘要
以钛酸丁酯为前驱体,采用溶胶-凝胶工艺成功制备了TiO2薄膜.利用反射式椭圆偏振光谱仪测量了薄膜的椭偏参量Ψ和Δ,并用Cauchy模型对椭偏参数进行数据拟合,得到了薄膜的厚度和光学常数在380—800nm的色散关系.用分光光度计测量了薄膜的反射率,并用干涉法计算薄膜的厚度;使用原子力显微镜观测了薄膜的表面微结构,分析讨论了不同退火温度处理的薄膜微结构与光学常数之间的关系.研究结果表明,Cauchy模型能较好地符合溶胶-凝胶TiO2薄膜的光学常数色散关系,得到了薄膜的折射率和消光系数随波长的变化规律;薄膜光学常数的大小与薄膜的微结构有关;理论模拟的反射率与实际测量的反射率非常符合;干涉法计算得到的薄膜厚度,与椭偏光谱测试的结果也一致,两者相对偏差仅为2.5%左右.
Nanostructured titanium oxide films were deposited on silicon substrate via sol-gel dip coating method with tetrabutyl titanate as precursor. With reflective spectroscopic ellipsometry, the ellipsometric parameters Ψ and Δ of TiO2 films were measured. Then, with the Cauchy model, the ellipsometric data were fitted, and both the thickness and the optical constants at 380—800 nm wavelength of the films were obtained. A comparison was made between the reflectance of the films derived with the spectrophotometer and the simulated results. Meanwhile, the thickness of the films was calculated by interference method. Moreover, with the atomic force microscopy the surface microstructures of the films annealed at different temperatures were observed, and the relationship between the surface microstructures and optical constants of films was further discussed. The results showed that Cauchy model works well in describing the dispersion relationship of the TiO_2 films, and the variation rules of optical constants （the refractive index, the extinction coefficient） with wavelength were obtained. The optical constants of the films were related with the microstructure. Those simulated reflectance spectrum accorded well with the measured result. And with a deviation of only 2.5%, the calculated value of the thickness was in accordance with which was obtained by spectroscopic ellipsometry.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2009年第11期8027-8032,共6页
Acta Physica Sinica
基金
国家高技术研究发展计划(批准号:2008AA8041606)
国家自然科学基金(批准号:50752001
50802064)资助的课题~~
