Extreme ultraviolet lithography (EUVL) is a leading next generation lithography technology. Significant progress has been made in developing mask fabrication processes for EUVL. The mask blank for EUVL consists of a low thermal expansion material substrate having a square photomask form factor that is coated with Mo/Si multilayers. SEMI standards are being developed for mask substrates and mounting. Several commercial suppliers are developing polishing processes for LTEM substrates, and they are progressing toward meeting the requirements for flatness, surface roughness, and defects defined in the a draft SEMI standard. One of the challenges in implementing EUVL is to economically fabricate multilayer-coated mask blanks with no printable defects. Significant progress has been made in developing mask blank multilayer coating processes with low added defect density. Besides lowering the added defect density, methods to reduce defect printability, such as defect compensation and buffer layer smoothing, are being developed. Experiments indicate that Mo/Si multilayers that are deposited with ion beam deposition tend to smooth substrate defects, and buffer layer films are being designed to enhance this effect. Targets for buffer layer smoothing are being defined using defect printability simulations. A method for using an electron beam to repair substrate defects after multilayer coating is also being investigated. The mask patterning process for EUVL is nearly the same as that for conventional binary optical lithography masks. EUVL mask patterning efforts are focused on developing the EUV-specific aspects of the patterning process. Eight absorbers have been evaluated against the requirements for EUVL masks, and two absorbers appear most promising. Conventional membrane pellicles are not practical for EUVL, so thermophoretic protection is being developed. Experiments have indicated that thermophoretic protection is effective for >125 nm particles down to at least 50 mTorr pressure. A removable pellicle will be used to protect the mask from defects at all times except during wafer exposure.
Skip Nav Destination
Article navigation
November 2001
This content was originally published in
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena
The 45th international conference on electron, ion, and photon beam technology and nanofabrication
29 May-1 June 2001
Washington, DC (USA)
Research Article|
November 01 2001
Review of progress in extreme ultraviolet lithography masks
Scott Hector;
Scott Hector
Motorola, Digital DNA™ Laboratories, Austin, Texas 78721
Search for other works by this author on:
Pawitter Mangat
Pawitter Mangat
Motorola, Digital DNA™ Laboratories, Tempe, Arizona 85284
Search for other works by this author on:
J. Vac. Sci. Technol. B 19, 2612–2616 (2001)
Article history
Received:
June 15 2001
Accepted:
July 30 2001
Citation
Scott Hector, Pawitter Mangat; Review of progress in extreme ultraviolet lithography masks. J. Vac. Sci. Technol. B 1 November 2001; 19 (6): 2612–2616. https://doi.org/10.1116/1.1408957
Download citation file:
Pay-Per-View Access
$40.00
Sign In
You could not be signed in. Please check your credentials and make sure you have an active account and try again.
Citing articles via
Future of plasma etching for microelectronics: Challenges and opportunities
Gottlieb S. Oehrlein, Stephan M. Brandstadter, et al.
Transferable GeSn ribbon photodetectors for high-speed short-wave infrared photonic applications
Haochen Zhao, Suho Park, et al.
Machine learning driven measurement of high-aspect-ratio nanostructures using Mueller matrix spectroscopic ellipsometry
Shiva Mudide, Nick Keller, et al.
Related Content
Extreme ultraviolet lithography: A review
J. Vac. Sci. Technol. B (October 2007)
Modeling of protection schemes for critical surfaces under low pressure conditions: Comparison between analytical and numerical approach
J. Vac. Sci. Technol. B (November 2005)
Recent advance in protection technology for extreme ultraviolet lithography masks under low-pressure condition
J. Vac. Sci. Technol. B (January 2008)
High transmission pellicles for extreme ultraviolet lithography reticle protection
J. Vac. Sci. Technol. B (November 2010)
Effect of reverse flow by differential pressure on the protection of critical surfaces against particle contamination
J. Vac. Sci. Technol. B (June 2006)