Analysis of Chemical and Morphological Changes of Phenol Formaldehyde-based Photoresist Surface caused by O2 Plasma

  • Shutov, D.A. (Department of Electronic Devices & Materials Technology, Ivanovo State University of Chemistry & Technology) ;
  • Kang, Seung-Youl (IT Convergence & Components Laboratory, ETRI) ;
  • Baek, Kyu-Ha (IT Convergence & Components Laboratory, ETRI) ;
  • Suh, Kyung-Soo (IT Convergence & Components Laboratory, ETRI) ;
  • Min, Nam-Ki (Department of Control and Instrumentation Engineering, Korea University) ;
  • Kwon, Kwang-Ho (Department of Control and Instrumentation Engineering, Korea University)
  • Published : 2007.10.31


Chemical and morphological changes of phenol formaldehyde-based photoresist after $O_2$ radiofrequency(RF) plasma treatment depending on exposure time and source power were investigated. It was found that etch rate of photoresist sharply increased after discharge turn on and reached a limit with increase in plasma exposure time. Contact angle measurements and X-ray photoelectron spectroscopy(XPS) analysis showed that the surface chemical structure become nearly constant after 15 sec of the treatment. Atomic force microprobe(AFM) measurements were shown that surface roughness was increased with plasma exposure time.


  1. E. Froschle and R. Backhus, 'Der Einfluss von sauerstoff auf lichtempfindlichkeit und bildqualitat des Photolacks KTFR', Solid-State Electronics, Vol. 14, No.2, p. 95, 1971
  2. S. M. Irving, 'A plasma oxidation process for removing photoresist films', Solid State Technol., Vol. 14, p. 47, 1971
  3. F.-W. Breitbarth, E. Ducke, and H.-J. Tiller, 'EPR investigation of plasma-chemical resist etching in $O_2$ and $O_{2}/CF_{4}$ discharges', Plasma Chemistry and Plasma Processing, Vol. 10, No.3, p. 377, 1990
  4. V. A. Titov, T. G. Shikova, E. V. Kuvaldina, and V. V. Rybkin, 'Kinetic features of the formation of gaseous products upon oxygen-plasma surface treatment of polyethylene, polypropylene, poly(ethylene terephthalate), and polyimide films', High Energy Chemistry, Vol. 36 No.5, p. 354, 2002
  5. C. D. Dimitrakopoulos and P. L. Malenfant, 'Organic thin film transistors for large area electronics', Adv. Mater. Vol. 14, No.2, p. 99, 2002
  6. M. S. Kim, N.-K. Min, S. J. Yun, H. W. Lee, A. Efremov, and K.-H. Kwon, 'On the etching mechanism of $ZrO_2$ thin films in inductively coupled $BCl_{3}/Ar$ plasma', Microelectronics Engineering, in press
  7. Practical Surface Analysis by Auger and X-ray Photoelectron Spectroscopy, Briggs, D. and Seach, M.P., Eds., Chichester: Wiley, 1983
  8. Handbook of X-ray Photoelectron Spectroscopy, J. F. Moulder at aI., Phisical Electronics: Minnesota, 1995
  9. F. M. Fowkes, 'Attractive forces at interfaces', Ind. Eng. Chern., Vol. 56, No. 12, p. 40, 1964
  10. D. K. Owens and R. C. Wendt, 'Estimation of the surface free energy of polymers', J. Appl. Polym. Sci., Vol. 13, p. 1741, 1969
  11. M. Ya. Digilov, A. I. Zhikharev, and G. V. Neiman, 'Effect of plasma and electrochemical treatment on the dispersion and polar components of the surface energy of carbon fibers', Mechanics of Composite Materials, Vol. 27, No.4, p. 372, 1992