Dr. Cheng Wang Profile

Dr. Cheng Wang

at Lawrence Berkeley National Lab

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Author

Publications (11)

Proceedings Article | 10 April 2024 Presentation

Characterization of chemical/structural information of latent image via critical-dimension resonant soft x-ray scattering

Qi Zhang, Weilun Chao, Warren Holcomb, Ryan Miyakawa, Dinesh Kumar, Ricardo Ruiz, Andrew Neureuther, Patrick Naulleau, Cheng Wang

Proceedings Volume 12955, 129550A (2024) https://doi.org/10.1117/12.3010967

KEYWORDS: Scattering, X-rays, X-ray imaging, X-ray characterization, Photoresist materials, X-ray sources, Data modeling, Light scattering, Laser scattering, Extreme ultraviolet lithography

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Proceedings Article | 22 November 2023 Poster

Metrology development on latent images via critical-dimension resonant soft x-ray scattering

Qi Zhang, Weilun Chao, Warren Holcomb, Ryan Miyakawa, Ricardo Ruiz, Dinesh Kumar, Andrew Neureuther, Patrick Naulleau, Cheng Wang

Proceedings Volume PC12750, PC1275012 (2023) https://doi.org/10.1117/12.2689943

KEYWORDS: Scattering, X-rays, X-ray imaging, Metrology, Systems modeling, X-ray sources, X-ray characterization, Time metrology, Spatial resolution, Simulations

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Proceedings Article | 30 April 2023 Presentation

A holistic approach to high precision patterning science

Ricardo Ruiz, Stacey Bent, Samuel Blau, Brett Helms, Frances Houle, Oleg Kostko, Patrick Naulleau, Paul Nealey, Christopher Ober, Dahyun Oh, Rachel Segalman, Cheng Wang

Proceedings Volume PC12497, PC124970J (2023) https://doi.org/10.1117/12.2662699

KEYWORDS: Optical lithography, Stochastic processes, Photoresist materials, Molecular self-assembly, Materials processing, Extreme ultraviolet lithography, Extreme ultraviolet, X-ray characterization, Semiconductors, Semiconductor manufacturing

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Proceedings Article | 11 November 2022 Presentation

Advancing spatiochemical metrology via resonant soft x-rays

Cheng Wang

Proceedings Volume PC12292, PC1229204 (2022) https://doi.org/10.1117/12.2642893

KEYWORDS: X-rays, Metrology, Image processing, Optical lithography, X-ray lithography, Spatial resolution, Scattering, Photoresist processing, Nanostructuring, Lithography

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Proceedings Article | 24 March 2020 Presentation

Probing buried structures in Inorganic-organic hybrid resists with energy-tunable X-rays (Conference Presentation)

Isvar Cordova, Luke Long, Guillaume Freychet, Cheng Wang, P. Naulleau

Proceedings Volume 11323, 113231P (2020) https://doi.org/10.1117/12.2552178

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Proceedings Article | 24 March 2020 Presentation

Critical-dimension grazing-incidence small angle X-Ray scattering: applications and development (Conference Presentation)

Guillaume Freychet, Dinesh Kumar, Isvar Cordova, Ron Pandolfi, Patrick Naulleau, Cheng Wang, Alex Hexemer

Proceedings Volume 11325, 113251A (2020) https://doi.org/10.1117/12.2552155

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Proceedings Article | 16 October 2019 Presentation

Leveraging chemical contrast to spotlight the latent profile of novel resists (Conference Presentation)

Isvar Cordova, Guillaume Freychet, Luke Long, Scott Dhuey, Cheng Wang, Patrick Naulleau

Proceedings Volume 11147, 111470Y (2019) https://doi.org/10.1117/12.2539040

KEYWORDS: Line edge roughness, X-ray imaging, X-rays, Lithography, Scattering, Extreme ultraviolet, Photodetectors, Grazing incidence, Carbon, Chemistry

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The development of novel resists that can match the challenges posed by the next generation of lithography partly hinges on our ability to develop new methods for extracting spatial information with sub-nm precision at each step of the lithographic process. This is particularly important for EUV resists, which tend to suffer from the seemingly inescapable trade-off between improving photon sensitivity and resolution, while reducing line edge roughness (LER). The strategies used to optimize this trade-off rely on tailoring the physicochemical mechanisms that take place before the final development of the resists, thus finding a way to characterize the structure of their latent image is critical to future progress. To meet some of these challenges, resonant x-ray scattering (ReXS) has emerged as a powerful technique which leverages the chemical contrast that exists between exposed and unexposed regions before the final development step in order to produce the average cross-sectional profile of the latent image with sub-nm precision. Most recently, the ReXS technique was demonstrated in a grazing incidence configuration by leveraging contrast in the carbon element’s local chemistry in order to extract the latent image of a patterned chemically amplified resist (CARs) directly on a silicon substrate[1]. In this work, we show how this capability may be extended to extract chemical contrast from other active elements in a given resist and expand on the potential benefits and drawbacks (i.e. beam damage, experimental configurations, and LER sensitivity) of performing such measurements both before and after the post-exposure baking step has taken place. Finally, we will present comparisons between the latent image profile collected at various resonant x-ray energies and the final developed structure corresponding to a variety of modern commercial resists used both for e-beam and EUV lithography. Such unique spatiochemical information should provide useful guidelines for both the synthesis and processing of the next generations of resist materials. [1] G. Freychet, I.A. Cordova, T. McAfee, D. Kumar, R.J. Pandolfi, C. Anderson, P. Naulleau, C. Wang, A. Hexemer, Using resonant soft x-ray scattering to image patterns on undeveloped resists, SPIE2018.

SPIE Journal Paper | 3 May 2019 Open Access

Reconstructing the three-dimensional latent image of extreme ultraviolet resists with resonant soft x-ray scattering

Guillaume Freychet, Isvar Cordova, Terry McAfee, Dinesh Kumar, Ronald Pandolfi, Chris Anderson, Scott Dhuey, Patrick Naulleau, Cheng Wang, Alexander Hexemer

JM3, Vol. 18, Issue 02, 024003, (May 2019) https://doi.org/10.1117/12.10.1117/1.JMM.18.2.024003

KEYWORDS: Scattering, X-rays, 3D image reconstruction, Extreme ultraviolet, X-ray imaging, Extreme ultraviolet lithography, 3D image processing, Modulation, Carbon, Image enhancement

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Proceedings Article | 26 March 2019 Presentation

Latent imaging of resists via resonant x-ray scattering: unraveling the effects of chain scission to chemical amplification (Conference Presentation)

Isvar Cordova, Guillaume Freychet, Scott Dhuey, Alexander Hexemer, Patrick Naulleau, Cheng Wang

Proceedings Volume 10959, 109590K (2019) https://doi.org/10.1117/12.2515166

KEYWORDS: Scattering, X-ray imaging, X-rays, Laser scattering, Electron beam lithography, Image processing, Line edge roughness, 3D image processing, Lithography, Photoresist processing

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Even though instrumentation for electron beam lithography (EBL) has progressed immensely since it was first introduced almost 50 years ago[1], enabling beam spot sizes below 5 nm for certain systems, its lithographic resolution limits are still bound by the primary and secondary electron scattering processes that occur when a specific resist is exposed. As the feature sizes become smaller and resists designed with higher sensitivities, these stochastic processes play an increasing role in the resulting line edge roughness (LER) thus leading to an effect known as shot noise. Unfortunately, unraveling the impact of these processes from the impact of the development step is partly hindered by our inability to measure the 3D profile of the latent image from resists directly after exposure. Furthermore, given the recent rise of chemically-amplified resists (CARs) used for the next generation extreme ultraviolet lithography (EUV), it has become even more critical to find ways to characterize and investigate the shot noise effect. In this work, we tackle this challenge by applying the resonant soft x-ray scattering (RSoXS) technique in a grazing incidence configuration to extract the cross-sectional profile of resists that have already been patterned, but have yet to be developed (i.e., latent image). We find that the difference in chemistry induced by the chain scission process in exposed PMMA and CAR resists is enough to produce enough scattering contrast at certain X-ray energies near the absorption edge of carbon in order to provide a latent image profile of the pattern with sub-nanometer resolution. In this paper, we will compare the latent image profiles extracted from this RSoXS data to the profiles obtained after development, as well as expand on the nature of this chemical contrast mechanism. We will show how this scattering data may be interpreted and the information used to shed light on the nature of the resolution limit of a specific combination of resist and exposure plus development conditions. Finally, we will elaborate on the impact of the measurement itself on the resulting pattern morphology as well as how similar insights might be gained across other types of resists. 1. Hans C. Pfeiffer, } "Direct write electron beam lithography: a historical overview", Proc. SPIE 7823, Photomask Technology 2010, 782316 (24 September 2010); doi: 10.1117/12.868477

Proceedings Article | 9 October 2018 Presentation + Paper

Using resonant soft x-ray scattering to image patterns on undeveloped resists

Guillaume Freychet, Isvar Cordova, Terry McAfee, Dinesh Kumar, Ronald Pandolfi, Chris Anderson, Patrick Naulleau, Cheng Wang, Alexander Hexemer

Proceedings Volume 10809, 108090V (2018) https://doi.org/10.1117/12.2502769

KEYWORDS: Scattering, X-rays, Extreme ultraviolet lithography, Modulation, Extreme ultraviolet, Carbon, X-ray imaging, Absorption, 3D image reconstruction, Laser scattering

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Proceedings Article | 17 October 2013 Paper

Morphology study on ternary blend polymer solar cell to achieve improved device performance

Yu Gu, Cheng Wang, Feng Liu, Jihua Chen, Thomas Russell

Proceedings Volume 8830, 883012 (2013) https://doi.org/10.1117/12.2026621

KEYWORDS: Crystals, Polymers, Solar cells, Scattering, Thin films, Binary data, Annealing, Grazing incidence, Absorption, Crystallography

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Showing 5 of 11 publications

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