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3 August 2015 Sensitivity analysis and line edge roughness determination of 28-nm pitch silicon fins using Mueller matrix spectroscopic ellipsometry-based optical critical dimension metrology
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Abstract
Measurement and control of line edge roughness (LER) is one of the most challenging issues facing patterning technology. As the critical dimensions (CDs) of patterned structures decrease, an LER of only a few nanometers negatively impacts device performance. Here, Mueller matrix (MM) spectroscopic ellipsometry-based scatterometry is used to characterize LER in periodic line-space structures in 28-nm pitch Si fin samples fabricated by directed self-assembly patterning. The optical response of the MM elements is influenced by structural parameters like pitch, CDs, height, and side-wall angle, as well as the optical properties of the materials. Evaluation and decoupling MM element response to LER from other structural parameters requires sensitivity analysis using scatterometry models that include LER. Here, an approach is developed that can be used to characterize LER in Si fins by comparing the optical responses generated by systematically varying the grating shape and measurement conditions. Finally, the validity of this approach is established by comparing the results obtained from power spectral density analysis of top down scanning electron microscope images and cross-sectional transmission electron microscope image of the 28-nm pitch Si fins.
CC BY: © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.
Dhairya J. Dixit, Samuel O’Mullane, Sravan Sunkoju, Abhishek Gottipati, Erik R. Hosler, Vimal K. Kamineni, Moshe E. Preil, Nick Keller, Joseph Race, Gangadhara Raja Muthinti, and Alain C. Diebold "Sensitivity analysis and line edge roughness determination of 28-nm pitch silicon fins using Mueller matrix spectroscopic ellipsometry-based optical critical dimension metrology," Journal of Micro/Nanolithography, MEMS, and MOEMS 14(3), 031208 (3 August 2015). https://doi.org/10.1117/1.JMM.14.3.031208
Published: 3 August 2015
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CITATIONS
Cited by 19 scholarly publications.
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KEYWORDS
Line edge roughness

Silicon

Scatterometry

Data modeling

Optical components

Picosecond phenomena

Scanning electron microscopy

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