Does high-NA EUV require tighter mask roughness specifications: a simulation study

Rik Jonckheere; Lawrence S. Melvin III

doi:10.1117/12.2643247

1 December 2022 Does high-NA EUV require tighter mask roughness specifications: a simulation study

Proceedings Volume 12292, International Conference on Extreme Ultraviolet Lithography 2022; 122920L (2022) https://doi.org/10.1117/12.2643247
Event: SPIE Photomask Technology + EUV Lithography, 2022, Monterey, California, United States

Abstract

In follow-up of related contributions at the past three symposium editions, our simulation study arrived at this question. As shown before, (local) mask defects and non-local mask deficiencies (NLMDs) act as triggers for increased stochastic failure probability on the EUV imaged resist pattern on wafer. Mask roughness is such an NLMD. The three types studied comprise multilayer (ML) ripple, which relates to a non-fully planar coating of the ML mask stack, mask absorber lineedge roughness and roughening of the ML. For the latter the study was restricted to roughening of the ruthenium capping layer only, which may already happen during the patterning step of the absorber during mask making. Each of the 3 roughness types is studied standalone and in combination. An alternative technique is presented that allows to define tolerance limits for mask roughness, without requiring massive, time-consuming stochastic simulations. It is based on studying how roughness-induced background light is passing through the projection optics. Our results, for anamorphic imaging at 0.55 NA, suggest the importance of limiting mask roughness beyond state-of-the-art.

Conference Presentation

Citation Download Citation

Rik Jonckheere and Lawrence S. Melvin III "Does high-NA EUV require tighter mask roughness specifications: a simulation study", Proc. SPIE 12292, International Conference on Extreme Ultraviolet Lithography 2022, 122920L (1 December 2022); https://doi.org/10.1117/12.2643247

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