Model-based breakdown of resist and mask contributions to local CDU for sub-30-nm contact holes in EUV lithography

Insung Kim, Changmin Park, Myeongsu Hwang, Jeong Ho Yeo, Jae W. Hahn

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5 Citations (Scopus)


The resist and mask contributions to the local critical dimension uniformity (L.CDU) of 30-nm contact holes (CHs) printed using extreme ultra-violet lithography (EUVL) are decomposed quantitatively by three independent budget breakdown methods. An asymptotic behavior model is proposed for the prediction of the resist-only contribution via a shifted and averaged multiple exposure (SAME) method that statistically averages out the collective mask local contributions. The other two budget breakdown methods of assessing, the variance of site-to-site difference for the derivation of resist-only contribution and the global mask error enhancement factor (G.MEEF) for the mask-only contribution, are performed and compared to the resist and mask contributions from the SAME method. The three budget breakdown methods consistently indicate that approximately 75-80% of L.CDU is attributed to the resist and process regardless of the process conditions, such as post exposure bake (PEB) temperature, PEB time, and exposure dose. L.CDU exhibits a linear correlation with 1/sqrt(dose), which is a potential indication that photon shot noise (PSN) could be a key contributor to the L.CDU on a wafer. Although a significant reduction of the total L.CDU is observed in the low PEB temperature process, i.e., high exposure dose, a relatively small change in the ratio of the resist-to-mask contribution may be observed because the chemical contrast enhancement by acid diffusion reduction is relatively small compared to PSN reduction.

Original languageEnglish
Pages (from-to)48-53
Number of pages6
JournalMicroelectronic Engineering
Publication statusPublished - 2014 Jul 1

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Electrical and Electronic Engineering


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