A stochastic resist simulator has first been calibrated to experimental results performed on a commercially available EUV resist, and subsequently has been used to study the influence of acid/base quenching rate and the polymer deprotection rate on resist LER for 22 nm half-pitch lines/spaces. Results indicate that larger quenching rates and smaller deprotection rates result in improved LER performance by causing an increase in the dose to size. With nominal quenching rate determined from literature, halving the deprotection rate relative to nominal value reduces the LER by 33%, while the dose to size increases by 2x. With nominal deprotection rate determined from literature, results indicate a low sensitivity of LER to quenching rate. Expected noise at the line edge calculated by using a shot noise model accounting for absorbed photons, acid, and base count, provides a good explanation for the LER trends calculated for several reaction rate scenarios.

Date Published: 6 April 2015
PDF: 7 pages
Proc. SPIE 9422, Extreme Ultraviolet (EUV) Lithography VI, 94222I (6 April 2015); doi: 10.1117/12.2087566

Published in SPIE Proceedings Vol. 9422:
Extreme Ultraviolet (EUV) Lithography VI
Obert R. Wood II; Eric M. Panning, Editor(s)