Dr. Monica Kempsell Sears Profile

Dr. Monica Kempsell Sears

Senior Product Engineer at Siemens AG

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Author

Publications (11)

Proceedings Article | 28 April 2023 Presentation + Paper

Application of resolution enhancement techniques at high NA EUV for next generation DRAM patterning

Ana-Maria Armeanu, Evgeny Malankin, Neal Lafferty, Chih-I Wei, Monica Kempsell Sears, Germain Fenger, Xima Zhang, Werner Gillijns, Darko Trivkovic, Ryoung-han Kim, Jeonghoon Lee

Proceedings Volume 12495, 124950A (2023) https://doi.org/10.1117/12.2660413

KEYWORDS: Photomasks, Extreme ultraviolet, Source mask optimization, Resolution enhancement technologies, Optical proximity correction, Lithography, Optical lithography, Capacitors, Semiconducting wafers, SRAF

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Among several critical layers of DRAM (dynamic random-access memory), capacitor holes of honeycomb arrays and bit-line-periphery (BLP) with Storage Node Landing Pad (SNLP) are the most critical layers in terms of patterning difficulty level. The honeycomb array hole layer has the highest density among various hole array types, and it is a complex lithography step since this layer is key in determining the performance of the DRAM. BLP with SNLP includes hole type and bi-directional line/space (L/S) design, and industry is considering a single exposure solution, compared to a three-mask solution using ArF immersion [1]. This BLP layer of 10nm DRAM has 2 different types of pattern topologies, hole array and bi-direction line/space: it is a very challenging single exposure level. In this paper, we discuss patterning challenges that come as consequences of industry trends in DRAM cell size reduction [2,3]. To keep up with this trend and to propose a single mask solution for bit-line-periphery, storage node landing pads and aggressive cell array pitches are considered along with resolution enhancement techniques (RET) for high-NA anamorphic EUV (NA=0.55) lithography. This study uses computational lithography such as source mask optimization (SMO) to find optimal off-axis illumination and optimal placement of sub-resolution assist features (SRAF) on the mask whilst considering the manufacturing rules checks (MRC constraints) for anamorphic EUV masks. In order to achieve that, a screening Design Technology Co-optimization (DTCO) experiment is done. The purpose is to identify cell array pitches in between 24nm and 32nm which satisfy both scaling requirements and patterning fidelity, preferred orientation of layout, and mask biasing scheme for various cell arrays. Lithography metrics like common depth of focus (cDoF), exposure latitude (EL), image contrast, and image log slope (ILS) are used to decide what is optimal way to expose on wafer. For the sake of completeness of the study, mask materials are compared. Indeed, in EUV domain there is interest to use alternative mask absorbers like Ruthenium alloys as an alternative to Tantalum-based absorbers [4,5,6].

Proceedings Article | 28 April 2023 Poster + Paper

Impact of mask rule constraints on ideal SRAF placement

Monica Kempsell Sears, Farah Huq Kmiec, Neal Lafferty, John Sturtevant

Proceedings Volume 12494, 124941C (2023) https://doi.org/10.1117/12.2657767

KEYWORDS: SRAF, Printing, Extreme ultraviolet, Deep ultraviolet, Image quality, Lithography

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Proceedings Article | 12 April 2013 Paper

Pupil wavefront manipulation to compensate for mask topography effects in optical nanolithography

Monica Kempsell Sears, Bruce Smith

Proceedings Volume 8683, 86830G (2013) https://doi.org/10.1117/12.2010034

KEYWORDS: Photomasks, Wavefronts, Monochromatic aberrations, Spherical lenses, Diffraction, Nanolithography, Data modeling, Lithography, Neodymium, Semiconducting wafers

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SPIE Journal Paper | 6 February 2013

Modeling the effects of pupil-manipulated spherical aberration in optical nanolithography

Monica Kempsell Sears, Bruce Smith

JM3, Vol. 12, Issue 01, 013008, (February 2013) https://doi.org/10.1117/12.10.1117/1.JMM.12.1.013008

KEYWORDS: Spherical lenses, Monochromatic aberrations, Diffraction, Finite element methods, Photomasks, Wavefronts, Nanolithography, Lithography, Error analysis, Silicon

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Proceedings Article | 13 March 2012 Paper

Pupil wavefront manipulation for optical nanolithography

Monica Kempsell Sears, Joost Bekaert, Bruce Smith

Proceedings Volume 8326, 832611 (2012) https://doi.org/10.1117/12.917440

KEYWORDS: Photomasks, Monochromatic aberrations, Spherical lenses, Finite element methods, Wavefronts, Diffraction, Binary data, Lithography, Phase shifts, Scanners

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Proceedings Article | 23 March 2011 Paper

Extending SMO into the lens pupil domain

Monica Kempsell Sears, Germain Fenger, Julien Mailfert, Bruce Smith

Proceedings Volume 7973, 79731B (2011) https://doi.org/10.1117/12.879058

KEYWORDS: Finite element methods, Monochromatic aberrations, Photomasks, Source mask optimization, Diffraction, Wavefronts, Lithography, Spherical lenses, Semiconductors, Binary data

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SPIE Journal Paper | 1 October 2009

Inverse lithography for 45-nm-node contact holes at 1.35 numerical aperture

Monica Kempsell, Eric Hendrickx, Alexander Tritchkov, Kyohei Sakajiri, Kenichi Yasui, Susuki Yoshitake, Yuri Granik, Geert Vandenberghe, Bruce Smith

JM3, Vol. 8, Issue 04, 043001, (October 2009) https://doi.org/10.1117/12.10.1117/1.3263702

KEYWORDS: Photomasks, Atrial fibrillation, Image quality, Photovoltaics, Lithography, Optical proximity correction, Semiconducting wafers, Phase shifts, Model-based design, Lithographic illumination

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Proceedings Article | 13 March 2009 Paper

Application of pixel-based mask optimization technique for high transmission attenuated PSM

Kyohei Sakajiri, Alexander Trichkov, Yuri Granik, Eric Hendrickx, Geert Vandenberghe, Monica Kempsell, Germain Fenger, Klaus Boehm, Thomas Scheruebl

Proceedings Volume 7275, 72750X (2009) https://doi.org/10.1117/12.813753

KEYWORDS: Photomasks, SRAF, Semiconducting wafers, Printing, Lithography, Source mask optimization, Electroluminescence, Manufacturing, Optical lithography, Reticles

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Proceedings Article | 17 October 2008 Paper

AIMS-45 image validation of contact hole patterns after inverse lithography at NA 1.35

E. Hendrickx, R. Birkner, M. Kempsell, A. Tritchkov, G. Vandenberghe, T. Scheruebl

Proceedings Volume 7122, 71221E (2008) https://doi.org/10.1117/12.801559

KEYWORDS: Atrial fibrillation, Lithography, Semiconducting wafers, Photomasks, Electroluminescence, Lithographic illumination, Reticles, Printing, Optical proximity correction, Scanners

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Proceedings Article | 7 March 2008 Paper

Fitness and runtime correlation of compact model complexity

Alexander Drozdov, Monica Kempsell, Yuri Granik

Proceedings Volume 6924, 692445 (2008) https://doi.org/10.1117/12.777403

KEYWORDS: Data modeling, Optical proximity correction, Performance modeling, Systems modeling, Optical lithography, Databases, Visualization, Diffusion, System on a chip, Calibration

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Proceedings Article | 7 March 2008 Paper

Hyper-NA imaging of 45nm node random CH layouts using inverse lithography

E. Hendrickx, A. Tritchkov, K. Sakajiri, Y. Granik, M. Kempsell, G. Vandenberghe

Proceedings Volume 6924, 69240L (2008) https://doi.org/10.1117/12.771961

KEYWORDS: Atrial fibrillation, Photomasks, Lithography, Reticles, Lithographic illumination, Photovoltaics, Optical proximity correction, Semiconducting wafers, Printing, Scanning electron microscopy

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Showing 5 of 11 publications

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