基于相位偏移干涉术的薄膜厚度测量方法

Measuring thin-film thickness with phase-shift interferometry

为解决薄膜厚度的高精度测量问题,提出一种基于相位偏移干涉术的薄膜厚度测量新方法,利用该方法对一个实际SiO2薄膜样片进行测试,通过对所获取的干涉图进行相位解包及数据分析处理,实现对薄膜样片厚度的精确测试。结果表明:该方法具有非接触和测量精度高等优点,所测薄膜厚度的峰谷值为0.162μm,均方根值为0.043μm,为薄膜工艺的进一步研究提供了检测方法上的技术保障。

High-precision measurement of thin-film is a precondition for the process optimization and diagnositcs in the thin-film preparation. Interferometric metrology is a widely accepted highprecison measurement technology which takes wavelength as the measurement unit. A novel measurement method of thin-film thickness based on phase-shift interferometry is presented. The precision measurement for the thickness of SiOz thin-film sample was realized after the phase unwrapping and data processing for the obtained interferogram were implemented. The results show that this method has the advantages of noncontact and high accuracy, and the PV and RMS values of the measured thin-film thickness are 0. 162μm and 0. 043 μm respectively.