Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2015 Mar 18:5:9235.
doi: 10.1038/srep09235.

Beyond EUV lithography: a comparative study of efficient photoresists' performance

Nassir Mojarad  1 , Jens Gobrecht  1 , Yasin Ekinci  1
Affiliations

Beyond EUV lithography: a comparative study of efficient photoresists' performance

Nassir Mojarad et al. Sci Rep. .

Abstract

Extreme ultraviolet (EUV) lithography at 13.5 nm is the main candidate for patterning integrated circuits and reaching sub-10-nm resolution within the next decade. Should photon-based lithography still be used for patterning smaller feature sizes, beyond EUV (BEUV) lithography at 6.x nm wavelength is an option that could potentially meet the rigid demands of the semiconductor industry. We demonstrate simultaneous characterization of the resolution, line-edge roughness, and sensitivity of distinct photoresists at BEUV and compare their properties when exposed to EUV under the same conditions. By using interference lithography at these wavelengths, we show the possibility for patterning beyond 22 nm resolution and characterize the impact of using higher energy photons on the line-edge roughness and exposure latitude. We observe high sensitivity of the photoresist performance on its chemical content and compare their overall performance using the Z-parameter criterion. Interestingly, inorganic photoresists have much better performance at BEUV, while organic chemically-amplified photoresists would need serious adaptations for being used at such wavelength. Our results have immediate implications for deeper understanding of the radiation chemistry of novel photoresists at the EUV and soft X-ray spectra.

PubMed Disclaimer

Figures

Figure 1
Figure 1. Interference lithography and patterning line-space structures.
(a) Schematic of interference lithography using a broadband mask for making line-space patterns. (b) Scanning-electron micrographs of Inpria IB (first row), HSQ (second row), and CAR (third row) at EUV (left column) and BEUV (right column). The half-pitch of each image is HPmin and is stated under it. Yellow traces show the analyzed line profile, overlaid on the corresponding lines.
Figure 2
Figure 2. Line-edge roughness and critical dimension of Inpria IB.
(a) LER and (b) critical dimension as a function of dose-on-wafer for different half-pitch values, exposed at EUV (squares) and BEUV (triangles).
Figure 3
Figure 3. Resolution, line-edge roughness and sensitivity characterization of the three photoresists.
(a) LER as a function of HP of Inpria IB (red), HSQ (blue), and CAR (green), exposed at EUV (squares) and BEUV (triangles). (b) Normalized thickness of the photoresists exposed through an open frame as a function of Dw. Dashed line indicate D0 values for each case. (c) Measured QD (solid) and calculated Ql (dashed) values of the photoresists. Gray bars represent calculated Ql values for elements present in the chemical formula of the photoresists.
Figure 4
Figure 4. Z-parameters.
Overall RLS characterization of the photoresists and their evaluated Z-parameters. At (a) EUV and (b) BEUV.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Tallents G., Wagenaars E. & Pert G. Optical Lithography at EUV Wavelengths. Nat Photonics 4, 809–811, 10.1038/Nphoton.2010.277 (2010). - DOI
    1. Wagner C. & Harned N. EUV Lithography Lithography Gets Extreme. Nat Photonics 4, 24–26, 10.1038/nphoton.2009.251 (2010). - DOI
    1. Oda S. & Ferry D. Silicon nanoelectronics. (Taylor and Francis, Boca Raton USA, 2006).
    1. Peeters R. et al. ASML's NXE platform performance and volume introduction. Proc SPIE 8679 10.1117/12.2010932 (2013). - DOI
    1. Willson C. G. & Roman B. J. The future of lithography: SEMATECH Litho Forum 2008. ACS Nano 2, 1323–1328, 10.1021/Nn800410c (2008). - DOI - PubMed

LinkOut - more resources