With photolithography being pushed to its limits, semiconductor device performance is becoming increasingly more sensitive to lithographic variations. More advanced lithography tools, metrology and photomasks are helping address issues like minimum feature size, tight CD control, and limited process windows. Mask registration is becoming even more important in the low k1 regime, where overlay can have a huge impact on the overall device performance and drive the error budget into unsatisfactory compromises.
FLASH memory technology requires a tighter overlay control compared to logic devices. Charge retention and programming performance are particularly sensitive to overlay. In this paper, we analyze the impact of photomask registration on NOR FLASH memory fabrication using Exploratory Data Analysis approach.
Fast and accurate reticle defect assessment becomes increasingly important because wafer critical dimensions continue to shrink and mask inspection equipment has moved into the UV range thereby increasing the number of detected reticle defects. Defect size is not sufficient in determining if a defect prints or does not print and the threshold size for printing defects can vary broadly between 0.35 (lambda) /NA. At the low k1 factors required to print current technology feature sizes, correlation between reticle and wafer CDs ceases to be linear. The impact of reticle defects on CDs therefore, is more critical than for previous technologies and defect size, shape, and proximity to other features must be taken into consideration. Presented in this paper is an evaluation of different methods to determine the accuracy of imaging prediction for reticle defects, decreasing the time to results in a prediction environment by accelerating the decision process. These methods include printability based on aerial image and the in-line STARlight Contamination Printability Index.
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.