Comparison of deposition techniques for Mo/Si reflective multilayers for EUV mask blanks

Katrina Rook; Antonio Checco; Paul Turner; Ashish A. Kulkarni; Kenji Yamamoto; Meng H. Lee

doi:10.1117/12.2600972

12 October 2021 Comparison of deposition techniques for Mo/Si reflective multilayers for EUV mask blanks

Katrina Rook, Antonio Checco, Paul Turner, Ashish A. Kulkarni, Kenji Yamamoto, Meng H. Lee

Proceedings Volume 11854, International Conference on Extreme Ultraviolet Lithography 2021; 1185415 (2021) https://doi.org/10.1117/12.2600972
Event: SPIE Photomask Technology + EUV Lithography, 2021, Online Only

Abstract

We present a comparison of the properties of the Mo/Si multilayers deposited by three techniques: secondary ion beam deposition (IBD), DC magnetron sputtering (MS), and biased-target ion beam deposition (BTIBD). Based on sputter simulations, we demonstrate that the energetics of the depositing adatoms and the intermixing depth depend strongly on the target/beam voltage, process pressure and target-to-substrate distance. XRR measurements indicate that the multilayers deposited by MS are much rougher than those deposited by IBD and BTIBD. SIMS and RBS measurements suggest that the Mo layers have low contamination of Fe and Al indicating insignificant beam overspray onto the target mounting material, as well as minimal Ar implantation. High-resolution TEM analysis shows intermixed layer thickness in the range of 0.3 to 1.9 nm and interfacial roughness in the range of 100 to 500 pm. Optical calculations suggest that the observed level of contamination is expected to have minimal impact on the EUV peak reflectivity. The intermixed layers could result in a 2-5% decrease in peak reflectivity. Further, the optical simulations predict that the 100-200pm range interfacial roughness in IBD and BTIBD cause a <0.5% reduction in peak reflectivity, whereas the 200-500pm range interfacial roughness in MS films is expected to compromise the peak reflectivity by up to 5%. This comparison of a variety of thin film techniques for the deposition of Mo and Si has allowed us to gain a deeper insight into the challenges faced during the fabrication of EUV mask blanks.

Conference Presentation

Citation Download Citation

Katrina Rook, Antonio Checco, Paul Turner, Ashish A. Kulkarni, Kenji Yamamoto, and Meng H. Lee "Comparison of deposition techniques for Mo/Si reflective multilayers for EUV mask blanks", Proc. SPIE 11854, International Conference on Extreme Ultraviolet Lithography 2021, 1185415 (12 October 2021); https://doi.org/10.1117/12.2600972

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