In this paper we present a method to characterize scattered light in lithography scanners based on the measurement of the modulation transfer function (MTF) of the lens. This method provides a description of scattered light at all length scales, or spatial frequencies, relevant to lithographic printing. We also introduce a new automated technique based on scatterometry that improves the precision and repeatability of the MTF measurement. Modeling of flare is important to quantify the impact of scattered light on the critical dimension of the features printed on chips. We have developed simulation methods based on actual data from our lithography scanners. Our model uses the MTF of the lens and the Fourier transform of the chip density map to calculate the flare distribution across the chips. We show that this approach is useful to understand how the characteristics of different scanners in our fabrication facilities might affect the critical dimension (CD) uniformity across our product chips.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
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.