22 March 2008 Evaluating diffraction based overlay metrology for double patterning technologies
Author Affiliations +
Abstract
Demanding sub-45 nm node lithographic methodologies such as double patterning (DPT) pose significant challenges for overlay metrology. In this paper, we investigate scatterometry methods as an alternative approach to meet these stringent new metrology requirements. We used a spectroscopic diffraction-based overlay (DBO) measurement technique in which registration errors are extracted from specially designed diffraction targets for double patterning. The results of overlay measurements are compared to traditional bar-in-bar targets. A comparison between DBO measurements and CD-SEM measurements is done to show the correlation between the two approaches. We discuss the total measurement uncertainty (TMU) requirements for sub-45 nm nodes and compare TMU from the different overlay approaches.
© (2008) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Chandra Saru Saravanan, Chandra Saru Saravanan, Yongdong Liu, Yongdong Liu, Prasad Dasari, Prasad Dasari, Oleg Kritsun, Oleg Kritsun, Catherine Volkman, Catherine Volkman, Alden Acheta, Alden Acheta, Bruno La Fontaine, Bruno La Fontaine, } "Evaluating diffraction based overlay metrology for double patterning technologies", Proc. SPIE 6922, Metrology, Inspection, and Process Control for Microlithography XXII, 69220C (22 March 2008); doi: 10.1117/12.774736; https://doi.org/10.1117/12.774736
PROCEEDINGS
12 PAGES


SHARE
Back to Top