The hidden energy tail of low energy electrons in EUV lithography

Roberto Fallica; Seyed Javid Rezvani; Stefano Nannarone; Sergei Borisov; Danilo De Simone; Sergey Babin; Gian Lorusso; Geert Vandenberghe

doi:10.1117/12.2514998

25 March 2019 The hidden energy tail of low energy electrons in EUV lithography

Roberto Fallica, Seyed Javid Rezvani, Stefano Nannarone, Sergei Borisov, Danilo De Simone, Sergey Babin, Gian Lorusso, Geert Vandenberghe

Author Affiliations +

Proceedings Volume 10960, Advances in Patterning Materials and Processes XXXVI; 1096009 (2019) https://doi.org/10.1117/12.2514998
Event: SPIE Advanced Lithography, 2019, San Jose, California, United States

Abstract

Electronic processes in extreme ultraviolet lithography are key to understand chemical reactions that lead to exposure of photoresist because of recent evidence that even very low kinetic energy electrons (E_k → 0 eV) might be very efficient in dissociating the molecules in photoresists. However, an assessment of the distribution of electrons involved in the cascade at kinetic energy approaching zero eV is not trivial in solid state. In this work, we use electron yield spectroscopy from thin photoresist films based on poly(hydroxystyrene) with and without photoacid generator (PAG). The results show that the addition of PAG boosts the electron yield by a factor 2 with respect to the polymer only photoresist. We then elaborate an analytical form of the transfer function that describes the physics of the photoemission by accounting for the energy distribution inside the photoresist material during exposure to extreme ultraviolet light. By fitting the model function to the spectroscopic data, we obtain an estimation for the distribution of electrons which lie inside the material at energy too low to be measured by an external detector, in other words the hidden tail of low energy electrons. For a quantitative comparison, we also use another approach based on MonteCarlo simulation of electronic scattering effects to calculate numerically the magnitude of the electron cascade. Using Chariot simulator, a statistically significant number of electronic trajectories (6 x10⁷) was calculated and the energy distribution of electrons are compared both outside and inside the photoresist film.

Citation Download Citation

Roberto Fallica, Seyed Javid Rezvani, Stefano Nannarone, Sergei Borisov, Danilo De Simone, Sergey Babin, Gian Lorusso, and Geert Vandenberghe "The hidden energy tail of low energy electrons in EUV lithography", Proc. SPIE 10960, Advances in Patterning Materials and Processes XXXVI, 1096009 (25 March 2019); https://doi.org/10.1117/12.2514998

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