@article{7398,
  author = {J. Q. Chen and E. Louis and R. Harmsen and T. Tsarfati and H. Wormeester and M. van Kampen and W. van Schaik and R. van de Kruijs and F. Bijkerk},
  title = {In situ ellipsometry study of atomic hydrogen etching of extreme ultraviolet induced carbon layers},
  abstract = {Atomic hydrogen based etching is generally considered an efficient method for the removal of carbon films resulting from photo-induced hydrocarbon dissociation, as occurs in extreme ultraviolet (EUV) photolithography environments. The etch rate of atomic hydrogen for three different kinds of carbon films was determined, namely for EUV-induced carbon, hot filament evaporated carbon and e-beam evaporated carbon. The etching process was monitored in situ by spectroscopic ellipsometry. The etch rate was found to depend on the type of carbon (polymer or graphite-like), on the layer thickness, and on the temperature. The EUV-induced carbon shows the highest etch rate, with a value of similar to 0.2 nm/min at a sample temperature of 60 degrees C. The more graphite-like carbon layers showed an etch rate that was about 10 times lower at this temperature. An activation energy of 0.45 eV was found for etching of the EUV-induced carbon layer. (C) 2011 Elsevier B. V. All rights reserved.},
  year = {2011},
  journal = {Applied Surface Science},
  volume = {258},
  pages = {7-12},
  month = {Oct},
  isbn = {0169-4332},
  doi = {10.1016/j.apsusc.2011.07.121},
  language = {English},
}