Accurate position measurement of a high-density beam spot array in digital maskless lithography

Dong Won Kang, Minwook Kang, Jae W. Hahn

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)


Since patterns in digital maskless lithography are formed by accumulating the exposure energy of a highdensity beam spot array, the accurate position measurement of the spot array is essential for the precise operation of the system.We propose a measurement technique for detecting the position of a high-density, subpixel size beam spot array with a charge-coupled device (CCD). In order to determine the position of each beam spot with a small number of CCD pixels, we assign 3 × 3 pixels of the CCD for each spot and scan the CCD to determine the signal of a center pixel. We numerically analyze the measurement uncertainty in the pixel position for various scanning conditions. We set up an experimental system for proof of concept and to detect the position of a 10 × 10 beam spot array with an uncertainty less than 100 nm. Additionally, the measurement uncertainty quantitatively matches the numerical analysis results.

Original languageEnglish
Pages (from-to)5862-5868
Number of pages7
JournalApplied Optics
Issue number23
Publication statusPublished - 2013 Aug 10

All Science Journal Classification (ASJC) codes

  • Atomic and Molecular Physics, and Optics
  • Engineering (miscellaneous)
  • Electrical and Electronic Engineering


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