Establish a complete focus-dose process window

Establish a complete focus-dose process window for the two-mirror faceted EUV projection system, including resist-printing behavior rather than only aerial-image resolution under the tested wafer defocus values.

Background

The paper synthesizes a binary mask for two closely spaced target lines and evaluates the corresponding aerial image for wafer defocus values from 0 to 5 nm. The peaks remain resolved in those simulations, but the calculation addresses only aerial intensity and does not determine how a photoresist would print the pattern across focus and dose variations. Thus, a complete lithographic process window remains unresolved.

References

The calculation does not establish a complete focus--dose process window.

— A Two-Mirror Faceted Projection System for EUV Lithography  (2609.11299 - Es'kin et al., 10 Sep 2026) in Section 5, subsection “Results of Optimizations,” paragraph beginning “We next evaluated mask synthesis…”