Interaction between EUV and construction materials

EUV scanners have been adopted worldwide for High-Volume Manufacturing (HVM) of sub-10nm lithography. The energetic photons and the ionization of the background gas by these photons result in a harsh environment for construction materials within the scanner. For application in upcoming EUV scanners, construction materials must be compatible with source powers of up to 1000 W, for >20 years of operation. This puts stringent requirements on the construction materials, manufacturing methods, cleaning and pretreatments. Besides effects of radiation and plasma, also surface charging risks must be considered, either from photoelectric effects or from ionization of the gas. In this paper, we will give an overview of the possible physical and chemical interactions between construction materials and photons and photon-induced plasma, and possible mitigations to prevent damage.