外差椭偏测量技术及其混频误差分析

Study on Heterodyne Ellipsometry and Error Analysis of Frequency Mixing

结合激光外差干涉术和反射式椭偏测量技术,设计了一种抗干扰能力强,快速、高精度测量纳米厚度薄膜光学参数的方法。着重分析并计算了非线性混频误差对测量精度的影响,其中塞曼激光和波片产生的光束椭偏化是关键因素。定义了评价因子以比较非线性混频误差的相对大小,这对外差椭偏纳米薄膜测量系统的设计有指导意义。

Optical heterodyne interferometry together with reflective ellipsometry,a fast measurement technology with high anti-interference performance was applied to nanometer film.The nonlinear error of frequency mixing in this measurement technology was analyzed and calculated,and it was pointed out that the elliptic polarization producing from Zeeman laser and the error of wave plate was the key issue.The definition of assessment factor was given for error estimation, which are of great benefit to the design of interferometric ellipsometry system.