Clear sub-resolution assist features for EUV

Martin Burkhardt; Greg McIntyre; Ralph Schlief; Lei Sun

doi:10.1117/12.2048311

17 April 2014 Clear sub-resolution assist features for EUV

Martin Burkhardt, Greg McIntyre, Ralph Schlief, Lei Sun

Proceedings Volume 9048, Extreme Ultraviolet (EUV) Lithography V; 904838 (2014) https://doi.org/10.1117/12.2048311
Event: SPIE Advanced Lithography, 2014, San Jose, California, United States

Abstract

In EUV lithography, the short wavelength of the light makes the topography of the mask stand out as three dimensional objects rather than thin masks. This generally requires use of a rigorous scattering simulator to calculate the diffracted orders of a mask in order to explain experimental results. In contrast, for optical proximity correction we cannot afford such detailed calculations and we would like to replace such detailed simulations with faster methods that give similar results. In this paper, we discuss observations we made during our printing experiments on a 0.33 NA EUV projection system. In order to extend the process window for non-nested trenches we introduced clear assist features. We observed strong tilt of Bossung curves and best focus shifts for certain pitches. These shifts can be explained by a phase difference between main and assist feature. This effect is very similar for both horizontal and vertical trenches, and it depends strongly on the illumination of the mask. We find that the best focus shift can be minimized for certain assist pitches and illumination conditions, but a general solution for random pitches appears not obvious.

Citation Download Citation

Martin Burkhardt, Greg McIntyre, Ralph Schlief, and Lei Sun "Clear sub-resolution assist features for EUV", Proc. SPIE 9048, Extreme Ultraviolet (EUV) Lithography V, 904838 (17 April 2014); https://doi.org/10.1117/12.2048311

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available