1. ITRS 2013 http://www.itrs.net
2. Underlayer designs to enhance the performance of EUV resists;Xu,2009
3. EUV underlayer materials for 22nm HP and Beyond;Yao,2011
4. Absorption and loss of film thickness in photoresists and underlayer materials upon irradiation at 13.5nm;Ho,2010
5. KLA-Tencor www.kla-tencor.com