Abstract

All-reflective, unobscured optical designs were developed to help identify a candidate first-generation system to be used in soft x-ray projection lithography. The resolution goal for all designs was 0.1 μm or better at design wavelength of 13 nm. Different design aspects, including usable field size, image distortion, number of mirrors, telecentricity, surface shape (spherical versus aspheric), and system packaging, were explored. Trade-off analyses between systems requiring scanning and full-format nonscanning systems were performed. The tolerance sensitivity analysis for a representative design showed that as-built performance will be driven by surface irregularity tolerance; we will briefly discuss the required tolerance levels.

© 1990 Optical Society of America