Si薄膜介电函数的椭偏光谱分析

Analysis of Dielectric Function of Silicon Films with Spectroscopic Ellipsometry

椭圆偏振光谱法(简称椭偏法)是一种常见的薄膜光学参数测试方法,具有灵敏度高、测试精度高且对测试样品无损伤等优点。首先系统介绍了有效介质近似(EMA)理论模型的基本原理,在此基础上,采用EMA模型对制备的Si薄膜样品的椭偏光谱测试结果进行了计算机拟合。结果表明,当设定样品结构为多晶、非晶和孔隙的混合物时,计算结果与测试数据完全吻合,由此得到了样品的微观结构信息。

Spectroscopic ellipsometry（SE）, a common method for films optic parameter test, owns several advantages, such as good sensitivity, excellent precision and scatheless to the samples. Firstly, the theory model of effective medium approximation（EMA） is introduced, then a computer theory fitting between EMA model and the SE measure results is operated. It indicates that the calculated results are consistent with the SE data perfectly when we assume the silicon film as a mixture of amorphous, polycrystalline and voids, and then the microstructure information of samples is obtained.