Optical design for EUV lithography source collector

Wolter I collector is the best collector for extreme ultraviolet (EUV) lithography, which has a series of nested mirrors. It has high collection efficiency and can obtain more uniform intensity distribution at the intermediate focus (IF). A new design with the calculation sequence from the outer mirror to the inner one on the premise of satisfying the requirements of the collector is introduced. Based on this concept, a computer program is established and the optical parameters of the collector using the program is calculated. The design results indicate that the collector satisfies all the requirements.