Photoresist film thickness for extreme ultraviolet lithography

Paul M. Dentinger; Gregory Frank Cardinale; Craig C. Henderson; Aaron Fisher; Avijit K. Ray-Chaudhuri

doi:10.1117/12.390098

21 July 2000 Photoresist film thickness for extreme ultraviolet lithography

Paul M. Dentinger, Gregory Frank Cardinale, Craig C. Henderson, Aaron Fisher, Avijit K. Ray-Chaudhuri

Proceedings Volume 3997, Emerging Lithographic Technologies IV; (2000) https://doi.org/10.1117/12.390098
Event: Microlithography 2000, 2000, Santa Clara, CA, United States

Abstract

The thickness of the photoresist directly impacts the etch stand off and may impact the number of defects in the spin- coated film. However, the maximum imaging layer thickness for extreme ultraviolet lithography (EUVL) is limited by absorption of the radiation. Attenuation in photoresist materials at relevant EUV wavelengths was calculated with atomic extinction coefficients provided from Henke et al. The calculations indicated that photoresist materials have an optical density (O.D.) of 4.0 micrometer^-1 (base e) so that 100 nm thick imaging layers have approximately 67% transmission at 13.4 nm wavelength. Using Prolith/3D^TM (Finle Technologies, Austin, TX) simulations of the effect of highly attenuating materials on sidewall slope were done and shown to be small. Imaging experiments were performed in a commercially-available DUV resist material on the 10 X II microstepper and with an improved EUV resist formulation. The imaging results agreed well with the calculations. Top down and cross-section images showed good sidewall profiles in 95 nm thick films at the nominal dose because over 68% of the energy was transmitted through the film. When the thickness of the film was increased, the dose was increased slightly to compensate for the absorption while good sidewall profiles and linearity were maintained. Photoresist thicknesses as high as 145 nm were imaged with a 35% increase in dose. Results are also shown for a single layer resist exposed at 175 nm thickness with only slight sidewall degradation. It is shown that the imaging layer thickness for 13.4 nm lithography is likely to be 120 +/- 15 nm. If 11.4 nm wavelength radiation is chosen for EUV lithography, it is shown that thicknesses of 170 nm is possible.

Citation Download Citation

Paul M. Dentinger, Gregory Frank Cardinale, Craig C. Henderson, Aaron Fisher, and Avijit K. Ray-Chaudhuri "Photoresist film thickness for extreme ultraviolet lithography", Proc. SPIE 3997, Emerging Lithographic Technologies IV, (21 July 2000); https://doi.org/10.1117/12.390098

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