At this year's SPIE, there are indications current EUV masks have problems with the Ta-based absorbers, leading to image fading.
Image fading has been covered in two papers:
I also covered it without paywall with less detail, mainly indicating the greater risk for stochastic defects: https://www.linkedin.com/pulse/euv-...-stochastic-defect-floor-frederick-chen-osfjc
Image fading leads to reduced contrast (i.e., difference between maximum and minimum intensities in an image).
Since image fading is a complex 3D mask effect, intense calculations are needed to assess this effect fully. This is a good role to be filled by the new cuLitho computational lithography platform.
Low-n absorbers replacing the Ta-based absorber (effectively enabling phase-shift masks) are widely proposed (including the two linked SPIE papers) to be the way to mitigate the image fading, but are not without other issues to be addressed.
Image fading has been covered in two papers:
I also covered it without paywall with less detail, mainly indicating the greater risk for stochastic defects: https://www.linkedin.com/pulse/euv-...-stochastic-defect-floor-frederick-chen-osfjc
Image fading leads to reduced contrast (i.e., difference between maximum and minimum intensities in an image).
Since image fading is a complex 3D mask effect, intense calculations are needed to assess this effect fully. This is a good role to be filled by the new cuLitho computational lithography platform.
Low-n absorbers replacing the Ta-based absorber (effectively enabling phase-shift masks) are widely proposed (including the two linked SPIE papers) to be the way to mitigate the image fading, but are not without other issues to be addressed.
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