Dynamic absorption coefficients of chemically amplified resists and nonchemically amplified resists at extreme ultraviolet

Research output: Contribution to journalArticlepeer-review


  • Roberto Fallica
  • Jason Stowers
  • Andrew Grenville
  • Yasin Ekinci

Colleges, School and Institutes

External organisations

  • Paul Scherrer Inst
  • Inpria
  • Paul Scherrer Institute


The dynamic absorption coefficients of several chemically amplified resists (CAR) and non-CAR extreme ultraviolet (EUV) photoresists are measured experimentally using a specifically developed setup in transmission mode at the x-ray interference lithography beamline of the Swiss Light Source. The absorption coefficient α and the Dill parameters ABC were measured with unprecedented accuracy. In general, the α of resists match very closely with the theoretical value calculated from elemental densities and absorption coefficients, whereas exceptions are observed. In addition, through the direct measurements of the absorption coefficients and dose-to-clear values, we introduce a new figure of merit called chemical sensitivity to account for all the postabsorption chemical reaction ongoing in the resist, which also predicts a quantitative clearing volume and clearing radius, due to the photon absorption in the resist. These parameters may help provide deeper insight into the underlying mechanisms of the EUV concepts of clearing volume and clearing radius, which are then defined and quantitatively calculated.


Original languageEnglish
Article number033506
Number of pages7
JournalJournal of Micro/Nanolithography, MEMS, and MOEMS
Issue number3
Publication statusPublished - 8 Aug 2016


  • absorption coefficient, clearing radius, clearing volume, chemical sensitivity, Dill parameters