Zernike coefficients: are they really enough?

Christopher J. Progler; Alfred K. K. Wong

doi:10.1117/12.389042

5 July 2000 Zernike coefficients: are they really enough?

Christopher J. Progler, Alfred K. K. Wong

Proceedings Volume 4000, Optical Microlithography XIII; (2000) https://doi.org/10.1117/12.389042
Event: Microlithography 2000, 2000, Santa Clara, CA, United States

Abstract

Zernike aberration coefficients are routinely used in simulation exercises for lithographic printing and the discovery of Zernike values is considered strategic for many lithographic process engineers. Thanks to progress in actinic interferometry and resist based evaluation techniques, reliable estimates of Zernike component magnitudes are possible in many cases. It is expected that wavelength reductions from 248 nm and 193 nm to 157 nm along with continued use of aspheric elements in high NA designs will lead to an increase in the component of wavefront aberration that is not adequately characterized by a 36 term Zernike polynomial. Wavefront errors not well characterized by a conventional Zernike fit are variously termed mid- spatial frequency errors, lack of fit, residuals, flare, scatter etc. This paper explores the importance, characterization and analysis of these residual errors and attempts to clarify the boundaries between the various classes of wavefront error. We find that an accurate assessment an model of lens performance requires the inclusion of both residual wavefront errors and flare effects in addition to the customary 36 term Zernike expansion.

Citation Download Citation

Christopher J. Progler and Alfred K. K. Wong "Zernike coefficients: are they really enough?", Proc. SPIE 4000, Optical Microlithography XIII, (5 July 2000); https://doi.org/10.1117/12.389042

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