EUV Lithography Without Pellicles: Accounting for Low Yields

EUV Lithography Without Pellicles: Accounting for Low Yields
by Fred Chen on 09-15-2025 at 6:00 am

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While stochastic defects link yield with the practical resolution of EUV lithography resulting from its quantum nature [1], very low yields of EUV processes are more readily linked to the use of EUV masks without pellicles. Pellicles are thin film membrane covers on masks (regardless of wavelength: EUV and DUV and i-line) used… Read More


IMEC’s Advanced Node Yield Model Now Addresses EUV Stochastics

IMEC’s Advanced Node Yield Model Now Addresses EUV Stochastics
by Fred Chen on 08-23-2025 at 8:00 am

EUV Stochastics

It lays the foundation for the Stochastics Resolution Gap

Chris Mack, the CTO of Fractilia, recently wrote of the “Stochastics Resolution Gap,” which is effectively limiting the manufacturability of EUV despite its ability to reach resolution limits approaching 10 nm in the lab [1,2]. As researchers have inevitably found, … Read More


High-NA Hard Sell: EUV Multi-patterning Practices Revealed, Depth of Focus Not Mentioned

High-NA Hard Sell: EUV Multi-patterning Practices Revealed, Depth of Focus Not Mentioned
by Fred Chen on 06-04-2025 at 10:00 am

HNA EUV Fred Chen

In High-NA EUV lithography systems, the numerical aperture (NA) is expanded from 0.33 to 0.55. This change has been marketed as allowing multi-patterning on the 0.33 NA EUV systems to be avoided. Only very recently have specific examples of this been provided [1]. In fact, it can be shown that double patterning has been implemented… Read More


Resist Loss Model for the EUV Stochastic Defectivity Cliffs

Resist Loss Model for the EUV Stochastic Defectivity Cliffs
by Fred Chen on 02-06-2025 at 10:00 am

Exposing EUV 1

The occurrences of notorious stochastic defects in EUV lithography have resulted in CD or corresponding dose windows with the lower and higher bounds being characterized as “cliffs” [1-3], since the defect density increases exponentially when approaching these bounds. The defects at lower doses have been attributed to the… Read More