摘要
薄膜厚度的测量在芯片制造和集成电路等领域中发挥着重要作用。椭偏法具备高测量精度的优点,利用宽谱测量方式可得到全光谱的椭偏参数,实现纳米级薄膜的厚度测量。为解决半导体领域常见的透明硅基底上薄膜厚度测量的问题并消除硅层的叠加信号,本文通过偏振分离式光谱干涉椭偏系统,搭建马赫曾德实验光路,实现了近红外波段硅基底上膜厚的测量,以100 nm厚度的二氧化硅薄膜为样品,实现了纳米级的测量精度。本文所提出的测量方法适用于透明或非透明基底的薄膜厚度测量,避免了检测过程的矫正步骤或光源更换,可应用于化学气相沉积、分子束外延等薄膜制备工艺和技术的成品的高精度检测。
Thickness measurement of the thin films is crucial for chip manufacturing and integrated circuits. Ellipsometry has the advantage of high measurement precision. The ellipsometry parameters of the full spectrum can be obtained by utilizing the broad spectrum measurement method to realize the thickness measurement of the nano-scale films. In order to solve the problem of film thickness measurement on the transparent silicon substrate which is often seen in the semiconductor field and eliminate the superimposed signal of the silicon layer, this paper proposed a polarization separation spectral interference ellipsometry system. A Mach-Zehnder interferometer was built to achieve the thickness measurement of the film on the silicon substrate in the near-infrared band. Taking the silica film with a thickness of 100 nm as the specimen, the measurement precision of nanometer scale was achieved. The method proposed in this paper is applicable to the thickness measurement of the thin films on transparent or opaque substrates, which avoids the correction steps in the detection process or the change of the incident wavelength. It can be used in the high-precision detection of the finished products of film preparation processes and technologies such as chemical vapor deposition and molecular beam epitaxy.
作者
张金旭
陈家扬
吴冠豪
ZHANG Jinxu;CHEN Jiayang;WU Guanhao(State Key Laboratory of Precision Measurement Technology and Instruments,Department of Precision Instrument,Tsinghua University,Beijing 100084,China)
出处
《计测技术》
2023年第1期122-127,共6页
Metrology & Measurement Technology
基金
自然科学基金重大研究计划培育项目(92150104)
自然科学基金重点项目(51835007)。
关键词
光谱干涉
椭偏
薄膜测量
偏振分离
spectral interference
ellipsometry
film measurement
polarization separation
作者简介
第一作者:张金旭(1999-),女,博士研究生,主要研究方向为光频梳光谱干涉厚度、折射率测量;通讯作者:吴冠豪(1981-),男,副教授,博士,主要研究方向为光频梳精密计量和激光雷达等。
