Presentation + Paper
21 November 2023 Validation of imaging benefits of dual monopole exposures
Author Affiliations +
Abstract
Dual monopole exposure has been proposed1 as a way to improve imaging performance in EUV lithography by reducing the loss of contrast from image fading caused by the image shifts for the two poles of a dipole source. Simulations showed that the imaging advantages can be significant, with more than 15% image contrast improvements predicted. This paper presents experimental wafer data to demonstrate and verify the predicted advantages. The observed imaging enhancements include: • 18% better NILS (Normalized Image Log-Slope) for 28nm pitch patterns. • Better tip-to-tip patterns enabling gaps as much as 3nm smaller than normal patterning. Tip-to-tip LCDU and exposure latitude were improved at the same time, for better overall T2T capability. • Best focus offsets between three pitches: P28, P56 and P96 was reduced from 30nm range to nearly zero. • Smaller LWR (Line-Width Roughness), as much as 20% depending on pitch. • Reduced micro-bridging defects in the “stochastic cliffs” of narrow trenches, as large as a 40X defect density reduction for narrow trenches with 82nm pitch. Our experimental results validate the substantial imaging advantages seen by initial simulations. In addition to verifying dual monopole imaging advantages, our experiments have measured the pole-to-pole image shift δxP2P, an important parameter relating to image contrast which has never been measured before. This important parameter depends on the detailed mask structure as well as the specific shape and location of the source poles. Our measured δxP2P was consistent with simulated expectations.
Conference Presentation
(2023) Published by SPIE. Downloading of the abstract is permitted for personal use only.
Timothy A. Brunner, Joern-Holger Franke, Vincent Truffert, Peter De Bisschop, Gijsbert Rispens, Edouard Duriau, Andre van Dijk, Cyrus Tabery, David Rio, Etienne De Poortere, Mark van de Kerkhof, and Eric Hendrickx "Validation of imaging benefits of dual monopole exposures", Proc. SPIE 12750, International Conference on Extreme Ultraviolet Lithography 2023, 1275006 (21 November 2023); https://doi.org/10.1117/12.2685543
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Semiconducting wafers

Stochastic processes

Nanoimprint lithography

Line width roughness

Printing

Optical lithography

Simulations

Back to Top