Paper
26 June 2003 Simulation study of process latitude for liquid immersion lithography
Author Affiliations +
Abstract
A simulation package has been developed for predicting the influence of immersion, i.e. the presence of a uniform liquid layer between the last objective lens and the photoresist, on optical projection lithography. This technology has engendered considerable interest in the microlithography community during the past year, as it enables the real part of the index of refraction in the image space, and thus the numerical aperture of the projection system, to be greater than unity. The simulation program described here involves a Maxwell vector solution approach, including polarization effects and arbitrary thin film multilayers. We examine here the improvement in process window afforded by immersion under a variety of conditions, including λ = 193 nm and 157 nm, annular illumination, and the use of alternating phase shift mask technology. Immersion allows printing of dense lines and spaces as small as 45 nm with acceptable process window. We also examine the effect of variations in liquid index on the process window and conclude that the index of the liquid must be known to and maintained within a few parts-per-million. This has important implications for the temperature control required in future liquid immersion projection systems.
© (2003) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
So-Yeon Baek, Daniel C. Cole, Mordechai Rothschild, Michael Switkes, Michael S. Yeung, and Eytan Barouch "Simulation study of process latitude for liquid immersion lithography", Proc. SPIE 5040, Optical Microlithography XVI, (26 June 2003); https://doi.org/10.1117/12.504600
Lens.org Logo
CITATIONS
Cited by 3 scholarly publications.
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Liquids

Binary data

Immersion lithography

Photoresist materials

Photomasks

Printing

Refraction

RELATED CONTENT

Partial Coherence In Projection Printing
Proceedings of SPIE (September 06 1978)
Adding grayscale layer to chrome photomasks
Proceedings of SPIE (October 20 2006)

Back to Top