Contamination Concerns at the Intermediate Focus of an Extreme Ultraviolet Light Source

摘要

The emission of species that can chemically or physically alter the surface of post intermediate-focus optics will increase the cost of ownership of such an EUV lithography tool past the point of cost effectiveness. To address this concern, the Center for Plasma-Material Interactions has developed the Sn Intermediate Focus Flux Emission Detector (SNIFFED). The effects of increasing buffer gas, increasing pressure, and chosen buffer gas species will be presented. Furthermore the presence of a secondary plasma, generated by EUV light will be analyzed and exposed as a potential issue in the strive for a contaminant free intermediate focus.