6 December 2004 Evaluation of multilayer damage in EUVL mask fabrication process
Author Affiliations +
To obtain a high throughput and good CD uniformity, the EUV reflectivity of EUVL masks must be high and very uniform. In this study, EUVL masks were fabricated, and the degradation in EUV reflectivity due to the fabrication process was evaluated. The damage to the multiplayer due to plasma etching appeared as a drop in peak reflectivity of about 2.0%. Etching the Cr buffer layer by a wet process reduced the value to within the measurement error. On the other hand, thermal damage appeared as both a drop in peak reflectivity and a shift in centroid wavelength. The drop in peak reflectivity was about 0.5-1.0% in the temperature range 140-240° C, and about 1.5% in the temperature range 260-280°C. The shift in centroid wavelength increased monotonically as the temperature rose from 180degrees C to 280°C. To ensure good CD uniformity, both the shift and the variation in centroid wavelength should be kept within ∓0.02 nm. If a drop in peak reflectivity of 1-2% is acceptable, annealing could be an effective way to adjust the centroid wavelength by as much as 0.10 nm with an accuracy of ∓0.01 nm.
© (2004) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Yuusuke Tanaka, Yuusuke Tanaka, Iwao Nishiyama, Iwao Nishiyama, Tsukasa Abe, Tsukasa Abe, Shiho Sasaki, Shiho Sasaki, Naoya Hayashi, Naoya Hayashi, } "Evaluation of multilayer damage in EUVL mask fabrication process", Proc. SPIE 5567, 24th Annual BACUS Symposium on Photomask Technology, (6 December 2004); doi: 10.1117/12.568984; https://doi.org/10.1117/12.568984


Status of EUV reflectometry at PTB
Proceedings of SPIE (May 06 2005)
Impact of mask absorber on EUV imaging performance
Proceedings of SPIE (May 15 2010)
Exposure contrast of an EUV mask
Proceedings of SPIE (August 28 2003)
Asymmetry and thickness effects in reflective EUV masks
Proceedings of SPIE (June 16 2003)
Mask topography simulation for EUV lithography
Proceedings of SPIE (June 25 1999)

Back to Top