Results obtained with high efficiency gratings for EUV application
1 CEA Grenoble - MINATEC, 17 rue des Martyrs, 38054 Grenoble, France
2 University of Wisconsin-Madison, Center for NanoTechnology, 425 Henry Mall, Suite 2130, WI 53706, USA
3 CNRS - LTM Grenoble - MINATEC, 17 rue des Martyrs, 38054 Grenoble, France
EUV lithography is planned to address the 22 nm node and beyond. Resolution limit for chemical amplified resists is one of the major issues for EUV lithography development. Currently, exposure studies concerning limit of resolution in resists are done in interferometer tools using synchrotron radiation light or EUV scanners.
In the framework of a stand alone EUV interferometer development, due to the low power of EUV sources, we have studied and developed new gratings with high efficiency. In this work, we developed gratings for EUV applications with a theoretical efficiency of 28% compared to gratings currently used in EUV interferometer (7% efficiency). Manufacturing process to realize 100 nm thick silicon membranes and gratings etched in molybdenum layer were developed. This high efficiency is a necessary step to build a successful standalone EUV interferometer. Membranes and gratings characteristics will be described. Exposure tests have been performed using synchrotron radiation. Results obtain with first and second order diffraction will be presented.
© Owned by the authors, published by EDP Sciences, 2011