Characteristics of Mo/Ru/Si multilayer reflector structure

TaeGeun Kim, WooSam Kim, In-Yong Kang+, Yong-Chae Chung+, SeungYoon Lee, and Jinho Ahn Div. of Adv. Materials Science and Engineering, Hanyang University +Dept. of Ceramic Engineering, Hanyang University 17 Haengdang-dong, Seongdong-gu, Seoul 133-791, Korea Introduction The characteristics of multilayer reflector is important since it is the core optical component for EUV projection. The multilayer structure as an EUV mask application should satisfy the following properies like high EUV reflectivity, low defect, compatibility with defect correction process and cleaning efficiency. The practical reflectivity of multilayer is always lower than that of the theorical value, and its main causes are non-ideal properties at the interface (interfacial mixing) and inside the films (density variation).