Extending a GTD-based image formation technique to EUV lithography

Andrew Khoh, Donis Flagello, Tom Milster, Byoung Il Choi, Ganesh S. Samudra, Yihong Wu

Research output: Contribution to journalConference articlepeer-review

1 Scopus citations


An image formation technique based on the Geometrical Theory of Diffraction was presented last conference. The technique is a scalar technique and is applicable to infinitely thin and perfectly conducting mask. We explore in this paper the extension of the technique to 1D Extreme Ultra-Violet(EUV) Lithography mask, taking into consideration both the material property and the topography of the mask. Vectorial nature of light is incorporated in the treatment. Results obtained are promising and encouraging. Computation time is relatively much shorter and the technique could simulate irradiance profile for any illumination angle. The technique is simple and elegant and lends understanding to image formation. We conclude that the asymmetry-through-focus characteristic usually found in EUV and Phase Mask imaging is an imaging phenomenon. We also conclude that corrections for proximity effect and pattern infidelity will be needed when EUV Lithography is introduced at the 32 nm node, assuming a system NA of 0.25. Lastly, for a partially coherent illumination, it appears necessary to compute the irradiance corresponding to each illumination point individually.

Original languageEnglish (US)
Pages (from-to)682-689
Number of pages8
JournalProceedings of SPIE - The International Society for Optical Engineering
Volume5037 II
StatePublished - 2003
EventEmerging Lithography Technologies VII - Santa Clara, CA, United States
Duration: Feb 25 2003Feb 27 2003


  • DER
  • EUV lithography
  • GTD
  • Image formation technique
  • OPC

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


Dive into the research topics of 'Extending a GTD-based image formation technique to EUV lithography'. Together they form a unique fingerprint.

Cite this