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Journal of Micro/Nanolithography, MEMS, and MOEMS • Open Access

Sensitivity analysis and line edge roughness determination of 28-nm pitch silicon fins using Mueller matrix spectroscopic ellipsometry-based optical critical dimension metrology
Author(s): 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; Alain C. Diebold

Paper 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.

Paper Details

Date Published: 3 August 2015
PDF: 13 pages
J. Micro/Nanolith. 14(3) 031208 doi: 10.1117/1.JMM.14.3.031208
Published in: Journal of Micro/Nanolithography, MEMS, and MOEMS Volume 14, Issue 3
Show Author Affiliations
Dhairya J. Dixit, SUNY Polytechnic Institute (United States)
Samuel O’Mullane, SUNY Polytechnic Institute (United States)
Sravan Sunkoju, SUNY Polytechnic Institute (United States)
Abhishek Gottipati, SUNY Polytechnic Institute (United States)
Erik R. Hosler, GLOBALFOUNDRIES Inc. (United States)
Vimal K. Kamineni, GLOBALFOUNDRIES Inc. (United States)
Moshe E. Preil, GLOBALFOUNDRIES Inc. (United States)
Nick Keller, Nanometrics Inc. (United States)
Joseph Race, Nanometrics Inc. (United States)
Gangadhara Raja Muthinti, IBM Research (United States)
Alain C. Diebold, SUNY Polytechnic Institute (United States)

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