不同制备工艺下氧化硅和氧化铪薄膜的椭偏光谱

椭偏技术是一种分析表面的光学方法,通过测量被测对象(样品)反射出的光线的偏振状态的变化情况来研究被测物质的性质。结合XRD和原子力显微镜等方法,利用椭圆偏振光谱仪测试了单层SiO2薄膜(K9基片)和单层HfO2薄膜(K9基片)的椭偏参数,并用Sellmeier模型和Cauchy模型对两种薄膜进行拟合,获得了SiO2薄膜和HfO2薄膜在300～800 nm波段内的色散关系。用X射线衍射仪确定薄膜结构,用原子力显微镜观察薄膜的微观形貌,分析表明:SiO2薄膜晶相结构呈现无定型结构,HfO2薄膜的晶相结构呈现单斜相结构;薄膜光学常数的大小和薄膜的表面形貌有关;Sellmeier和Cauchy模型较好地描述了该波段内薄膜的光学性能,并得到薄膜的折射率和消光系数等光学常数随波长的变化规律。

Spectroscopic ellipsometry of SiO2 and HfO2 thin films with different technics

Ellipsometry is an optical technique devoted to analyze the surface.It is based on the measurement of the variation of the polarization state of the light after reflection on a plane surface.In this work,XRD,atomic force microscopy(AFM) and SE were used to measure and analyze optical properties of SiO2 and HfO2 thin films.Sellmeier and Cauchy dispersion model were used to calculate the refractive index,extinction coefficient and thickness of thin films in the visible region of the spectrum between 300-800 nm.The XRD was used to confirm the phase structure of thin films,and the AFM was used to observe the surface microstructure of thin films.The results show that the phase structure of SiO2 film is amorphism,and the phase structure of HfO2 film is monoclinic.The thin film optical properties are correlative with thin film microstructure.Sellmeier and Cauchy dispersion model can describe optical properties of SiO2 and HfO2 film very well and the variation rule of the optical properties with wavelength can be obtained.