中国物理B ›› 2022, Vol. 31 ›› Issue (5): 50601-050601.doi: 10.1088/1674-1056/ac3225

• • 上一篇    下一篇

Characterization of a nano line width reference material based on metrological scanning electron microscope

Fang Wang(王芳)1, Yushu Shi(施玉书)1,†, Wei Li(李伟)1, Xiao Deng(邓晓)2, Xinbin Cheng(程鑫彬)2, Shu Zhang(张树)1, and Xixi Yu(余茜茜)1,3   

  1. 1 National Institute of Metrology, Beijing 100029, China;
    2 Tongji University, Shanghai 200092, China;
    3 Shenzhen Institute Technology Innovation, National Institute of Metrology, Shenzhen 518038, China
  • 收稿日期:2021-08-19 修回日期:2021-10-12 发布日期:2022-04-09
  • 通讯作者: Yushu Shi,E-mail:shiys@nim.ac.cn E-mail:shiys@nim.ac.cn
  • 基金资助:
    This work was supported by the National Key Research and Development Program of China (Grant No.2020YFF0218403) and the Basic Scientific Research Operating Fund of NIM (Grant No.AKYZD2007-1).

Characterization of a nano line width reference material based on metrological scanning electron microscope

Fang Wang(王芳)1, Yushu Shi(施玉书)1,†, Wei Li(李伟)1, Xiao Deng(邓晓)2, Xinbin Cheng(程鑫彬)2, Shu Zhang(张树)1, and Xixi Yu(余茜茜)1,3   

  1. 1 National Institute of Metrology, Beijing 100029, China;
    2 Tongji University, Shanghai 200092, China;
    3 Shenzhen Institute Technology Innovation, National Institute of Metrology, Shenzhen 518038, China
  • Received:2021-08-19 Revised:2021-10-12 Published:2022-04-09
  • Contact: Yushu Shi,E-mail:shiys@nim.ac.cn E-mail:shiys@nim.ac.cn
  • About author:2021-10-22
  • Supported by:
    This work was supported by the National Key Research and Development Program of China (Grant No.2020YFF0218403) and the Basic Scientific Research Operating Fund of NIM (Grant No.AKYZD2007-1).

摘要: The line width (often synonymously used for critical dimension, CD) is a crucial parameter in integrated circuits. To accurately control CD values in manufacturing, a reasonable CD reference material is required to calibrate the corresponding instruments. We develop a new reference material with nominal CDs of 160 nm, 80 nm, and 40 nm. The line features are investigated based on the metrological scanning electron microscope which is developed by the National Institute of Metrology (NIM) in China. Also, we propose a new characterization method for the precise measurement of CD values. After filtering and leveling the intensity profiles, the line features are characterized by the combination model of the Gaussian and Lorentz functions. The left and right edges of CD are automatically extracted with the profile decomposition and k-means algorithm. Then the width of the two edges at the half intensity position is regarded as the standard CD value. Finally, the measurement results are evaluated in terms of the sample, instrument, algorithm, and repeatability. The experiments indicate efficiency of the proposed method which can be easily applied in practice to accurately characterize CDs.

关键词: critical dimension, line width, metrological scanning electron microscopy, traceability

Abstract: The line width (often synonymously used for critical dimension, CD) is a crucial parameter in integrated circuits. To accurately control CD values in manufacturing, a reasonable CD reference material is required to calibrate the corresponding instruments. We develop a new reference material with nominal CDs of 160 nm, 80 nm, and 40 nm. The line features are investigated based on the metrological scanning electron microscope which is developed by the National Institute of Metrology (NIM) in China. Also, we propose a new characterization method for the precise measurement of CD values. After filtering and leveling the intensity profiles, the line features are characterized by the combination model of the Gaussian and Lorentz functions. The left and right edges of CD are automatically extracted with the profile decomposition and k-means algorithm. Then the width of the two edges at the half intensity position is regarded as the standard CD value. Finally, the measurement results are evaluated in terms of the sample, instrument, algorithm, and repeatability. The experiments indicate efficiency of the proposed method which can be easily applied in practice to accurately characterize CDs.

Key words: critical dimension, line width, metrological scanning electron microscopy, traceability

中图分类号:  (Metrology)

  • 06.20.-f
06.20.fb (Standards and calibration) 68.37.Hk (Scanning electron microscopy (SEM) (including EBIC))