Quantitative access to phase effects in high numerical aperture extreme-ultraviolet photomasks using aerial image metrology

Matthias Roesch; Grizelda Kersteen; Andreas Verch; Maximilian Albert; Philip Heringlake; Klaus Gwosch; Renzo Capelli

doi:10.1117/1.JMM.23.4.044001

8 October 2024 Quantitative access to phase effects in high numerical aperture extreme-ultraviolet photomasks using aerial image metrology

Matthias Roesch, Grizelda Kersteen, Andreas Verch, Maximilian Albert, Philip Heringlake, Klaus Gwosch, Renzo Capelli

Author Affiliations +

Journal of Micro/Nanopatterning, Materials, and Metrology, Vol. 23, Issue 4, 044001 (October 2024). https://doi.org/10.1117/1.JMM.23.4.044001

Abstract

Background

The upcoming introduction of high-numerical aperture extreme ultraviolet (EUV) lithography is accompanied by ongoing activities to mitigate the imaging issues combined with the 3D photomask absorber. In addition to suitable exposure and patterning techniques, the absorber material has a large impact on image contrast and the usable depth of focus.

Aim

The study of solutions to the imaging downsides combined with the EUV reflective mask typically is based on rigorous imaging simulations. We show that aerial image metrology using Aerial Image Measurement System (AIMS)^® EUV is a supplementary way to verify the impact of mask 3D effects in lithography.

Approach

An AIMS^® EUV study of the impact of mask 3D effects on the through-focus image formation in a three-beam interference regime is presented.

Results

Experiments on a 20-nm vertical equal lines and spaces clip using dedicated monopole illumination demonstrate a prominent, focus-dependent line-shape behavior for each of the pole positions. Applying an analytical model for three-beam-imaging in the presence of defocus and mask 3D effects, we obtain excellent agreement between measurements and theory that allows us to derive the mutual phase shifts of the single interference cross-terms involved.

Conclusions

Using AIMS^® EUV, an evaluation of the imaging impact of various absorber materials can be done experimentally without relying on wafer exposures.

Citation Download Citation

Matthias Roesch, Grizelda Kersteen, Andreas Verch, Maximilian Albert, Philip Heringlake, Klaus Gwosch, and Renzo Capelli "Quantitative access to phase effects in high numerical aperture extreme-ultraviolet photomasks using aerial image metrology," Journal of Micro/Nanopatterning, Materials, and Metrology 23(4), 044001 (8 October 2024). https://doi.org/10.1117/1.JMM.23.4.044001

Received: 24 July 2024; Accepted: 10 September 2024; Published: 8 October 2024

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

Members: $24.00

Non-members: $28.00 ADD TO CART

JOURNAL ARTICLE
8 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

3D mask effects

Light sources and illumination

Extreme ultraviolet

Diffraction

3D modeling

Extreme ultraviolet lithography

Phase shifts

Background

Aim

Approach

Results

Conclusions

Show All Keywords

Keywords/Phrases

Search In:

Publication Years