Aerial image measurement methods for fast aberration set-up and illumination pupil verification

Hans van der Laan; Marcel Dierichs; Henk van Greevenbroek; Elaine McCoo; Fred Stoffels; Richard Pongers; Rob Willekers

doi:10.1117/12.435757

14 September 2001 Aerial image measurement methods for fast aberration set-up and illumination pupil verification

Hans van der Laan, Marcel Dierichs, Henk van Greevenbroek, Elaine McCoo, Fred Stoffels, Richard Pongers, Rob Willekers

Proceedings Volume 4346, Optical Microlithography XIV; (2001) https://doi.org/10.1117/12.435757
Event: 26th Annual International Symposium on Microlithography, 2001, Santa Clara, CA, United States

Abstract

As feature size decreases, factors like lens aberrations and pupil illumination become increasingly important for the lithographer. Both factors can be quantified using the Transmission Image Sensor (TIS), a built-in measurement device on ASML Step & Scan systems. Advantages of the TIS include robustness and speed, because it is a straightforward measurement technique that does not involve exposure of resist. To allow for on-site minimization of lens aberrations, new lens types will incorporate additional manipulators. Consequently, fast and accurate in-situ measurement of aberrations such as coma and spherical is required. This is achieved by measuring the position of the aerial image at multiple illumination settings, using the flexibility of modern scanners to automatically set the numerical aperture and partial coherence. The accuracy of this technique, proven by strong correlation with interferometric and lithographic data, makes it suitable for system optimization. Regarding measurements of pupil illumination, the new TIS-based technique is compared with the conventional resist-based method. The latter images a defocused pinhole in resist, and is ideal for visual inspection. For the new method, the TIS is scanned in a defocused lateral plane to record the far field image of the pinhole. Quantitative results like pupil uniformity, ellipticity and sigma accuracy are easily obtained.

Citation Download Citation

Hans van der Laan, Marcel Dierichs, Henk van Greevenbroek, Elaine McCoo, Fred Stoffels, Richard Pongers, and Rob Willekers "Aerial image measurement methods for fast aberration set-up and illumination pupil verification", Proc. SPIE 4346, Optical Microlithography XIV, (14 September 2001); https://doi.org/10.1117/12.435757

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

Includes PDF, HTML & Video, when available