Precision optical aspheres for extreme ultraviolet lithography

摘要

We have demonstrated significant advances in the production of aspheric optics for extreme ultraviolet lithography. An optic has been fabricated with an aspheric departure of 1.5 (mu)m, a figure error of 0.7 nm rms and a nanoroughness of 0.25 nm rms. Further improvements are required in the figure and nanoroughness to reach high throughput and near diffraction limited performance in an EUVL system. 8 refs., 2 figs.