Development of a compact X-ray source and super-sensitization of photo resists for soft x-ray imaging

Tomoko Gowa*, Naoyuki Fukutake, Yoshimasa Hama, Kentaro Hizume, Takashi Kashino, Shigeru Kashiwagi, Ryunosuke Kuroda, Akihiko Masuda, Akihiro Oshima, Taku Saito, Kazuyuki Sakaue, Kunio Shinohara, Tomohiro Takahashi, Tatsuya Urakawa, Kiminori Ushida, Masakazu Washio

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


A compact soft X-ray source via inverse Compton scattering has been developed at Waseda University. The energies of the generated X-rays are within "water window" region (250 - 500 eV) and development of a soft X-ray microscope is expected which can get the elemental mapping of carbon and/or nitrogen without dehydration. We have studied to develop a high resolution soft X-ray imaging system with photo resists for nanoscale observation. However, the yield of generated X-rays had been too small for the practical use of the soft X-ray microscopy. To enhance the X-ray yield, we have upgraded the generation system and succeeded in increasing the detected photons 10-fold. Total generated photons were estimated to be over 1.5E+5 photons/s. Also, super-sensitization of photo resists has been attempted to reduce the required X-ray amount. By irradiating quasi-monochromatic X-rays in the water window region from synchrotron radiation at BL12 of the SAGA-LS, the sensitivity of a deep-UV photo resist, TDUR-P722 (Tokyo Ohka Kogyo Co., Ltd) was evaluated. After UV light (including 254 nm) exposure up to the sensitivity threshold and baking as PEB process, it was found that the resist becomes more sensitive. This UV "pre-exposure" method reduced the required 400 eV X-ray amount by over 65 %.

Original languageEnglish
Pages (from-to)691-696
Number of pages6
JournalJournal of Photopolymer Science and Technology
Issue number5
Publication statusPublished - 2009 Sept


  • Inverse compton scattering
  • Photo resist
  • Soft X-ray microscope

ASJC Scopus subject areas

  • Polymers and Plastics
  • Organic Chemistry
  • Materials Chemistry


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