Design of the double-telecentric high-aperture diffractive-refractive objectives

摘要

The possibility for achieving optical performance of objectives, including a minimum amount of diffractive lenses, comparable to optical performance of multiple-lens conventional objectives for nanolithography, is considered. The problem of chromatism connected with using excimer lasers is solved by applying aspheric substrates that help to reduce both axial color and spherochromatic aberration.