
Proceedings Paper
Cleaning of MoSi multilayer mask blanks for EUVLFormat | Member Price | Non-Member Price |
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$17.00 | $21.00 |
Paper Abstract
Extreme ultraviolet lithography (EUVL) is being considered as the enabler technology for the manufacturing of future
technology nodes (30 nm and beyond). EUV mask blanks are Bragg mirrors made of Mo and Si bilayers and tuned for
reflectivity at a wavelength λ ~13 nm. Implementation of EUVL requires that the mask blanks be free of defects at 30
nm or above. However, during the deposition of MoSi multilayers and later during the handling of blanks, defects are
added to the blank. Therefore, the cleaning of EUV mask blanks is a critical step in the manufacturing of future devices.
The particulate defects on the multilayer-coated mask blanks can either be embedded in or under the MoSi layers or
adhered to the top capping layer during the deposition process. The defects can also be added during the handling of
photomasks. Our previous studies have shown successful removal of the handling-related defects at SEMATECH's
Mask Blank Development Center (MBDC) in Albany, NY. However, cleaning embedded and adhered defects presents
new challenges. The cleaning method should not only be able to remove the particles, but also be compatible with the
mask blank materials. This precludes the use of any aggressive chemistry that may change the surface condition leading
to diminished mask blank reflectivity. The present work discusses the recent progress made at SEMATECH's MBDC in
cleaning backside Cr-coated mask blanks with a MoSi multilayer and a Si cap layer on the top surface. Here we present
our data that demonstrates successful removal of sub-100 nm particles added by the deposition process. Surface
morphology and defect composition on the surface of the MoSi multilayer are discussed. EUV reflectivity measurements
and atomic force microscopy (AFM) images of the mask blank before and after cleaning are presented. The present data
shows that no measurable damage to the EUV mask blank is caused by the cleaning processes developed at the MBDC.
Paper Details
Date Published: 20 October 2006
PDF: 9 pages
Proc. SPIE 6349, Photomask Technology 2006, 63492W (20 October 2006); doi: 10.1117/12.686556
Published in SPIE Proceedings Vol. 6349:
Photomask Technology 2006
Patrick M. Martin; Robert J. Naber, Editor(s)
PDF: 9 pages
Proc. SPIE 6349, Photomask Technology 2006, 63492W (20 October 2006); doi: 10.1117/12.686556
Show Author Affiliations
Vivek Kapila, Sematech, Inc. (United States)
Abbas Rastegar, Sematech, Inc. (United States)
Yoshiaki Ikuta, Sematech, Inc. (United States)
Abbas Rastegar, Sematech, Inc. (United States)
Yoshiaki Ikuta, Sematech, Inc. (United States)
Published in SPIE Proceedings Vol. 6349:
Photomask Technology 2006
Patrick M. Martin; Robert J. Naber, Editor(s)
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