Emulation of anamorphic imaging on the SHARP extreme ultraviolet mask microscope

Markus P. Benk; Antoine Wojdyla; Weilun Chao; Farhad H. Salmassi; Sharon R. Oh; Yow-Gwo Wang; Ryan H. Miyakawa; Patrick P. Naulleau; Kenneth A. Goldberg

doi:10.1117/1.JMM.15.3.033501

12 July 2016 Emulation of anamorphic imaging on the SHARP extreme ultraviolet mask microscope

Markus P. Benk, Antoine Wojdyla, Weilun Chao, Farhad H. Salmassi, Sharon R. Oh, Yow-Gwo Wang, Ryan H. Miyakawa, Patrick P. Naulleau, Kenneth A. Goldberg

Author Affiliations +

Journal of Micro/Nanolithography, MEMS, and MOEMS, Vol. 15, Issue 3, 033501 (July 2016). https://doi.org/10.1117/1.JMM.15.3.033501

Abstract

The SHARP high-numerical aperture actinic reticle review project is a synchrotron-based, extreme ultraviolet (EUV) microscope dedicated to photomask research. SHARP emulates the illumination and imaging conditions of current EUV lithography scanners and those several generations into the future. An anamorphic imaging optic with increased mask-side numerical aperture (NA) in the horizontal and increased demagnification in the vertical direction has been proposed to overcome limitations of current multilayer coatings and extend EUV lithography beyond 0.33 NA. Zoneplate lenses with an anamorphic 4×/8× NA of 0.55 are fabricated and installed in the SHARP microscope to emulate anamorphic imaging. SHARP’s Fourier synthesis illuminator with a range of angles exceeding the collected solid angle of the newly designed elliptical zoneplates can produce arbitrary angular source spectra matched to anamorphic imaging. A target with anamorphic dense features down to 50-nm critical dimension is fabricated using 40 nm of nickel as the absorber. In a demonstration experiment, anamorphic imaging at 0.55 4×/8× NA and 6 deg central ray angle (CRA) is compared with conventional imaging at 0.5 4× NA and 8 deg CRA. A significant contrast loss in horizontal features is observed in the conventional images. The anamorphic images show the same image quality in the horizontal and vertical directions.

Citation Download Citation

Markus P. Benk, Antoine Wojdyla, Weilun Chao, Farhad H. Salmassi, Sharon R. Oh, Yow-Gwo Wang, Ryan H. Miyakawa, Patrick P. Naulleau, and Kenneth A. Goldberg "Emulation of anamorphic imaging on the SHARP extreme ultraviolet mask microscope," Journal of Micro/Nanolithography, MEMS, and MOEMS 15(3), 033501 (12 July 2016). https://doi.org/10.1117/1.JMM.15.3.033501

Published: 12 July 2016

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

;

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE