Study of energy delivery and mean free path of low energy electrons in EUV resists

Suchit Bhattarai; Andrew R. Neureuther; Patrick P. Naulleau

doi:10.1117/12.2220390

25 March 2016 Study of energy delivery and mean free path of low energy electrons in EUV resists

Suchit Bhattarai, Andrew R. Neureuther, Patrick P. Naulleau

Proceedings Volume 9779, Advances in Patterning Materials and Processes XXXIII; 97790B (2016) https://doi.org/10.1117/12.2220390
Event: SPIE Advanced Lithography, 2016, San Jose, California, United States

Abstract

The relative importance of secondary electrons in delivering energy in photoresist films was assessed by performing large area exposures and by quantifying the inelastic mean free path of electrons in a leading chemically amplified positive tone EUV resist. A low energy electron microscope was used to directly pattern large (~15μm x 20μm) features with 15-80 eV electrons followed by analyzing the resulting dissolution rate contrast curve data. In the 40 to 80 eV regime the energy delivery was found to scale roughly proportionally with electron energy. In 15 to 30 eV regime however, this energy scaling did not explain the resist thickness loss data. The dose required to lower the resist thickness down to 20 nm was found to be 2-5X larger for 15 eV electrons than for 20, 25 and 30 eV electrons. Using scattering models from the literature including phonon scattering and optical data deduced electron energy loss spectroscopy and optical reflectometry, the inelastic mean free path values at energies between 10 eV and 92 eV range between about 2.8 and 0.6 nm respectively.

Citation Download Citation

Suchit Bhattarai, Andrew R. Neureuther, and Patrick P. Naulleau "Study of energy delivery and mean free path of low energy electrons in EUV resists", Proc. SPIE 9779, Advances in Patterning Materials and Processes XXXIII, 97790B (25 March 2016); https://doi.org/10.1117/12.2220390

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