Extreme UV, i.e. 13.5 nm, photons and photon-induced secondary electrons are the driving forces of mirror degradation in EUV lithography equipment. An understanding of the catalytic role of the mirror surface and the photochemical processes is required for controlling such mirror degradation. We used temperature programmed desorption and reflection-absorption infrared spectroscopy in a UHV chamber to characterize the binding structure and changes in the chemical composition of molecular contamination layers on the surface. The photochemical reactions of water, hydrocarbons and hydrogen on Ru(0001) were studied. We found that the dissociation of water on Ru is enhanced by EUV radiation, which lead to oxidation of the Ru surface. Secondly, the dissociation of ethanol into CO, hydrogen and carbon was investigated. Additionally, experiments showed that hydrogen radicals can reduce the oxidized surface, which was analysed by a reaction model that includes EUV induced oxidation by water and reduction by hydrogen
|Publication status||Published - 22 Jan 2013|
|Event||Physics@FOM Veldhoven 2013 - NH Koningshof, Veldhoven, Netherlands|
Duration: 22 Jan 2013 → 23 Jan 2013
|Conference||Physics@FOM Veldhoven 2013|
|Period||22/01/13 → 23/01/13|
Liu, F., Sturm, J. M., Osorio, E., van Kampen, M., Lee, C. J., & Bijkerk, F. (2013). Extreme Ultraviolet (EUV) induced surface chemistry on Ru(0001). -. Poster session presented at Physics@FOM Veldhoven 2013, Veldhoven, Netherlands.