27 March 2014 A chemical underlayer approach to mitigate shot noise in EUV contact hole patterning
Author Affiliations +
Shot noise is a significant issue in EUV lithography, especially in printing small area features like contact holes. This brings about LCDU (Local CD Uniformity) issue and LCDU-sensitivity tradeoff. This paper describes efforts to alleviate this issue through a novel EUV Underlayer (UL) chemistry design approach. The novel component “buffer” was introduced into EUV UL formulations to balance back exposure energy from UL to the resist at different incident positions. Measured back exposure dose from UL shows much lower variation (6σ/mean) compared with shot noise of resist absorbed dose. Thus summed energy variation will be suppressed when counting back exposure effect of UL, namely shot noise is reduced. Through reported shot noise model, our calculation suggests 30% sensitivity improvement and 13.4% shot noise suppression can be expected. Actual lithographic evaluations demonstrated simultaneous LCDU and sensitivity improvement. The feasibility of 30% sensitivity improvement by Metal hard mask (MHM) material was tested. The combination of buffer functionalized UL and MHM was modeled.
© (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Jin Li, Jin Li, Ide Yasuaki, Ide Yasuaki, Shigemasa Nakasugi, Shigemasa Nakasugi, Motoki Misumi, Motoki Misumi, Hiroshi Yanagita, Hiroshi Yanagita, Fumihiro Suzuki, Fumihiro Suzuki, Georg Pawlowski, Georg Pawlowski, JoonYeon Cho, JoonYeon Cho, Huirong Yao, Huirong Yao, Takanori Kudo, Takanori Kudo, Munirathna Padmanaban, Munirathna Padmanaban, YoungJun Her, YoungJun Her, Yi Cao, Yi Cao, "A chemical underlayer approach to mitigate shot noise in EUV contact hole patterning", Proc. SPIE 9051, Advances in Patterning Materials and Processes XXXI, 905117 (27 March 2014); doi: 10.1117/12.2046237; https://doi.org/10.1117/12.2046237


Mechanisms of EUV exposure: electrons and holes
Proceedings of SPIE (March 26 2017)
Patterning capabilities of EUV resists
Proceedings of SPIE (May 13 2004)
EUV lithography at the 22nm technology node
Proceedings of SPIE (March 22 2010)
Ultimate fine-pitch resist patterning using the ASET-HINA
Proceedings of SPIE (March 23 2006)
EUV resist requirements: absorbance and acid yield
Proceedings of SPIE (April 01 2009)

Back to Top