In order for the development of cleaning technology of extreme ultra violet lithography photomask, the behavior of Ru surfaces after treatment with ozonated deionized water (DIO 3 ) solution was studied using Ru and ruthenium oxide particles and 2 nm-thick Ru capping layers. No significant changes in crystalline structures or chemical states of the Ru surfaces, nor any similarities with the structures or states of ruthenium oxide, were observed after DIO 3 treatment. Oxidation of ruthenium to form RuO 2 or RuO 3 was not observed. Adsorption of H 2 O molecules on the Ru layer increased the surface roughness, but the desorption of H 2 O molecules recovered it. Local chemisorption of H 2 O molecules on the Ru surface may be the reason why rougher Ru surfaces were observed after DIO 3 cleaning.
Bibliographical noteFunding Information:
This work was financially supported by Hynix Semiconductor Inc. This work was also supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology ( 2010-0010573 ).
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Physics and Astronomy(all)
- Surfaces and Interfaces
- Surfaces, Coatings and Films