Designing metrology targets that mimic process device cell behavior is becoming a common component in overlay process control. For an advanced DRAM process (sub 20 nm node), the extreme illumination methods needed to pattern the critical device features makes it harder to control the aberration induced overlay delta between metrology target and device patterns. To compensate for this delta, a Non-Zero-Offset is applied to the metrology measurement that is based on a manual calibration measurement using CD-SEM Overlay.
In this paper, we document how this mismatch can be minimized through the right choice of metrology targets and measurement recipe.
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.