Dr. Thomas I. Wallow Profile

Dr. Thomas I. Wallow

at ASML

SPIE Involvement:

Conference Program Committee | Author | Editor

Publications (86)

Proceedings Article | 22 November 2023 Presentation

Probing EUV resist defect detectability using a SEM simulation framework

Thomas Wallow, Aiqin Jiang, Ton Kiers, Tim Houben, Chris Spence

Proceedings Volume PC12750, PC127500C (2023) https://doi.org/10.1117/12.2687837

KEYWORDS: Scanning electron microscopy, Defect detection, Extreme ultraviolet, Machine learning, Inspection

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Proceedings Article | 22 November 2023 Presentation

Resolution and patterning performance quantification using efficient e-beam metrology

Cyrus Tabery, Miao Wang, Victor Blanco Carballo, Eren Canga, Aiqin Jiang, Chris Spence, Tom Wallow

Proceedings Volume PC12750, PC127500B (2023) https://doi.org/10.1117/12.2688141

KEYWORDS: Electron beam lithography, Metrology, Design and modelling, Scanning laser ophthalmoscopy, Scanning electron microscopy, Line width roughness, Image enhancement, Failure analysis, Extreme ultraviolet, Etching

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Proceedings Article | 21 November 2023 Presentation + Paper

Mask error and its contribution to OPC model error for an EUV via layer

Adam Lyons, Tom Wallow, Chris Spence, Bríd Connolly, Christian Beurgel, Markus Bender

Proceedings Volume 12750, 127500E (2023) https://doi.org/10.1117/12.2687699

KEYWORDS: Optical proximity correction, Semiconducting wafers, Extreme ultraviolet, Data modeling, Calibration, Metrology, Finite element methods, Critical dimension metrology, Contour modeling, Computer simulations

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Proceedings Article | 1 December 2022 Presentation + Paper

Extreme ultraviolet lithography reticle local CD uniformity correlation to wafer local CD uniformity

Adam Lyons, Tom Wallow, Dong-Seok Nam, Gisung Yoon, Baorui Yang, Mike Hermes

Proceedings Volume 12293, 122930M (2022) https://doi.org/10.1117/12.2643523

KEYWORDS: Photomasks, Semiconducting wafers, Critical dimension metrology, Scanning electron microscopy, Reticles, Stochastic processes, Metrology, Extreme ultraviolet lithography, Image analysis

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Proceedings Article | 16 September 2022 Paper

Curvilinear EUV mask: development of innovative mask metrology

Maxence Delorme, Werner Gillijns, Christoph Hennerkes, Emily Gallagher, Adam Lyons, Mahmoud Mohsen, Tom Wallow

Proceedings Volume 12325, 123250L (2022) https://doi.org/10.1117/12.2642867

KEYWORDS: Photomasks, Optical proximity correction, Metrology, Scanning electron microscopy, Logic, Distortion, Extreme ultraviolet, Critical dimension metrology

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Recent developments in multi-beam mask writers (MBMW)1 enable the manufacturing of curvilinear masks. This promises higher patterning accuracy on wafer. The increased patterning flexibility takes us into new territories for mask manufacturing accuracy, precision and Mask Rule Check (MRC). MBMW allows Optical Proximity Correction (OPC) to venture into Inverse Lithography Technology (ILT) solutions, enabling accurate curvilinear masks. New challenges are also encountered when building OPC models that target ILT masks, such as on wafer metrology and pattern coverage. This exploration will be the focus of this study, in particular the MRC and mask characterization aspects, leveraging a new curvilinear reticle available at imec. As a result of its fully curvilinear nature, conventional mask metrology – solely based on cutline CDs – is no longer entirely adequate. Therefore, a new metrology flow must be developed to assess and quantify mask errors, relying on mask SEM image contour extraction and Mask Edge Placement Error (MEPE) evaluations. Our proposed flow has three steps: -Mask CDSEM images are loaded into a software, which enables an accurate contour extraction and alignment to the original design. The output of this exercise is a design file with open contours. - The output design file is converted into polygons (i.e., defining inside/outside polygons areas) by utilizing the original design as a guide. This allows for full compatibility with the next stage. -Lastly, a highly-sampled MEPE is determined for all polygons, both from the main and assisting features. The result is then analyzed offline. Ultimately, this curvilinear mask data analysis sequence was used on several subsets of the mask metrology dataset. In order to validate the approach, we reproduced the CD based metrology provided by the mask shop. We then expanded our scope to parametric curvilinear features, to find correlators (i.e. local design properties) to the observed mask error observed (e.g., polygon local curvature or density). Finally, ILT clips were used to verify the determined correlators.

Proceedings Article | 1 October 2021 Presentation

Statistical analysis of the impact of 2D reticle variability on wafer variability in advanced EUV nodes using large-scale Monte Carlo simulations

Luke Long, Adam Lyons, Tom Wallow

Proceedings Volume 11855, 1185513 (2021) https://doi.org/10.1117/12.2598992

KEYWORDS: Reticles, Monte Carlo methods, Statistical analysis, Photomasks, Semiconducting wafers, Extreme ultraviolet, SRAF, Optical proximity correction, Cadmium sulfide

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Proceedings Article | 28 September 2021 Presentation

Contour-based variability decomposition for stochastic band metrology

Thomas Wallow, Jiyou Fu, Jiao Liang, Jen-Shiang Wang, Jimmy Fan, Maxence Delorme, ChangAn Wang, Fahong Li, Vivek Jain, Rui Yuan

Proceedings Volume 11854, 118540E (2021) https://doi.org/10.1117/12.2601587

KEYWORDS: Metrology, Stochastic processes, Photomasks, Model-based design, Scanning electron microscopy, Line edge roughness, Optical lithography, Semiconducting wafers, Extreme ultraviolet, Wafer-level optics

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Proceedings Article | 26 February 2021 Presentation + Paper

Statistical analysis of the impact of 2D reticle variability on wafer variability in advanced EUV nodes using large-scale Monte Carlo simulations

Adam Lyons, Luke Long, Tom Wallow, Chris Spence, Ton Kiers, Paul van Adrichem, Vidya Vaenkatesan, Jiyou Fu, Christoph Hennerkes, Cyrus Tabery

Proceedings Volume 11609, 116090C (2021) https://doi.org/10.1117/12.2584744

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Proceedings Article | 13 October 2020 Poster + Paper

Mask contribution to OPC model accuracy

Adam Lyons, Tom Wallow, Christoph Hennerkes, Chris Spence, Maxence Delorme, David Rio, Dai Tsunoda, Yohei Torigoe, Masakazu Hamaji

Proceedings Volume 11517, 115171D (2020) https://doi.org/10.1117/12.2573160

KEYWORDS: Photomasks, Optical proximity correction, Data modeling, Process modeling, Extreme ultraviolet, Semiconducting wafers, Metrology, Calibration, Finite element methods

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Proceedings Article | 20 September 2020 Presentation

Free form data reduction for MPC

Dai Tsunoda, Yasuaki Horima, Yohei Torigoe, Brian Dillon, Adam Lyons, Tom Wallow, Kurt Wampler, Vincent Shu, Quan Zhang

Proceedings Volume 11518, 115180P (2020) https://doi.org/10.1117/12.2573132

KEYWORDS: Photomasks, Optical proximity correction, Lithography, Device simulation, Semiconducting wafers, Optical simulations

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Proceedings Article | 22 March 2018 Paper

Massive metrology using fast e-beam technology improves OPC model accuracy by >2x at faster turnaround time

Qian Zhao, Lei Wang, Jazer Wang, ChangAn Wang, Hong-Fei Shi, James Guerrero, Mu Feng, Qiang Zhang, Jiao Liang, Yunbo Guo, Chen Zhang, Tom Wallow, David Rio, Lester Wang, Alvin Wang, Jen-Shiang Wang, Keith Gronlund, Jun Lang, Kar Kit Koh, Dong Qing Zhang, Hongxin Zhang, Subramanian Krishnamurthy, Ray Fei, Chiawen Lin, Wei Fang, Fei Wang

Proceedings Volume 10585, 105852Q (2018) https://doi.org/10.1117/12.2299971

KEYWORDS: Metrology, Data modeling, Calibration, Optical proximity correction, Scanning electron microscopy, Image processing, Time metrology, Critical dimension metrology, Semiconducting wafers, Error analysis

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Classical SEM metrology, CD-SEM, uses low data rate and extensive frame-averaging technique to achieve high-quality SEM imaging for high-precision metrology. The drawbacks include prolonged data collection time and larger photoresist shrinkage due to excess electron dosage. This paper will introduce a novel e-beam metrology system based on a high data rate, large probe current, and ultra-low noise electron optics design. At the same level of metrology precision, this high speed e-beam metrology system could significantly shorten data collection time and reduce electron dosage. In this work, the data collection speed is higher than 7,000 images per hr. Moreover, a novel large field of view (LFOV) capability at high resolution was enabled by an advanced electron deflection system design. The area coverage by LFOV is >100x larger than classical SEM. Superior metrology precision throughout the whole image has been achieved, and high quality metrology data could be extracted from full field. This new capability on metrology will further improve metrology data collection speed to support the need for large volume of metrology data from OPC model calibration of next generation technology. The shrinking EPE (Edge Placement Error) budget places more stringent requirement on OPC model accuracy, which is increasingly limited by metrology errors. In the current practice of metrology data collection and data processing to model calibration flow, CD-SEM throughput becomes a bottleneck that limits the amount of metrology measurements available for OPC model calibration, impacting pattern coverage and model accuracy especially for 2D pattern prediction. To address the trade-off in metrology sampling and model accuracy constrained by the cycle time requirement, this paper employs the high speed e-beam metrology system and a new computational software solution to take full advantage of the large volume data and significantly reduce both systematic and random metrology errors. The new computational software enables users to generate large quantity of highly accurate EP (Edge Placement) gauges and significantly improve design pattern coverage with up to 5X gain in model prediction accuracy on complex 2D patterns. Overall, this work showed >2x improvement in OPC model accuracy at a faster model turn-around time.

Proceedings Article | 16 October 2017 Presentation + Paper

Measurement of through-focus EUV pattern shifts using the SHARP actinic microscope

Obert Wood, Yulu Chen, Pawitter Mangat, Kenneth Goldberg, Markus Benk, Bryan Kasprowicz, Henry Kamberian, Jeremy McCord, Thomas Wallow

Proceedings Volume 10450, 1045008 (2017) https://doi.org/10.1117/12.2280371

KEYWORDS: Extreme ultraviolet, Photomasks, Microscopes, Extreme ultraviolet lithography, 3D metrology, Reflectivity, Optical lithography, Image analysis, Image segmentation, Lithography

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Proceedings Article | 28 April 2017 Presentation

CD-SEM metrology and OPC modeling for 2D patterning in advanced technology nodes (Conference Presentation)

Thomas Wallow, Chen Zhang, Anita Fumar-Pici, Jun Chen, Bart Laenens, Christopher Spence, David Rio, Paul van Adrichem, Harm Dillen, Jing Wang, Peng-Cheng Yang, Werner Gillijns, Patrick Jaenen, Frieda van Roey, Jeroen van de Kerkhove, Sergey Babin

Proceedings Volume 10145, 101451Q (2017) https://doi.org/10.1117/12.2260443

KEYWORDS: Metrology, Optical proximity correction, Data modeling, Optical lithography, Signal to noise ratio, OLE for process control, Instrument modeling, Image analysis, Calibration, Metals

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In the course of assessing OPC compact modeling capabilities and future requirements, we chose to investigate the interface between CD-SEM metrology methods and OPC modeling in some detail. Two linked observations motivated our study: 1) OPC modeling is, in principle, agnostic of metrology methods and best practice implementation. 2) Metrology teams across the industry use a wide variety of equipment, hardware settings, and image/data analysis methods to generate the large volumes of CD-SEM measurement data that are required for OPC in advanced technology nodes. Initial analyses led to the conclusion that many independent best practice metrology choices based on systematic study as well as accumulated institutional knowledge and experience can be reasonably made. Furthermore, these choices can result in substantial variations in measurement of otherwise identical model calibration and verification patterns. We will describe several experimental 2D test cases (i.e., metal, via/cut layers) that examine how systematic changes in metrology practice impact both the metrology data itself and the resulting full chip compact model behavior. Assessment of specific methodology choices will include: • CD-SEM hardware configurations and settings: these may range from SEM beam conditions (voltage, current, etc.,) to magnification, to frame integration optimizations that balance signal-to-noise vs. resist damage. • Image and measurement optimization: these may include choice of smoothing filters for noise suppression, threshold settings, etc. • Pattern measurement methodologies: these may include sampling strategies, CD- and contour- based approaches, and various strategies to optimize the measurement of complex 2D shapes. In addition, we will present conceptual frameworks and experimental methods that allow practitioners of OPC metrology to assess impacts of metrology best practice choices on model behavior. Finally, we will also assess requirements posed by node scaling on OPC model accuracy, and evaluate potential consequences for CD-SEM metrology capabilities and practices.

Proceedings Article | 28 March 2017 Presentation + Paper

CD-SEM distortion quantification for EPE metrology and contour analysis

Harm Dillen, Ton Kiers, Sandip Halder, Thomas Wallow, Frieda van Roey

Proceedings Volume 10145, 1014515 (2017) https://doi.org/10.1117/12.2260664

KEYWORDS: Distortion, Scanning electron microscopy, Metrology, Data corrections, Image quality, Tolerancing, Optical proximity correction, Optical lithography, Visualization, Critical dimension metrology, Data modeling, Semiconducting wafers, Distance measurement, Error analysis, Calibration, Mathematical modeling, Performance modeling

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Proceedings Article | 27 March 2017 Presentation + Paper

Compact 2D OPC modeling of a metal oxide EUV resist for a 7nm node BEOL layer

Adam Lyons, David Rio, Sook Lee, Thomas Wallow, Maxence Delorme, Anita Fumar-Pici, Michael Kocsis, Peter de Schepper, Michael Greer, Jason Stowers, Werner Gillijns, Danilo De Simone, Joost Bekaert

Proceedings Volume 10143, 101431E (2017) https://doi.org/10.1117/12.2260441

KEYWORDS: Optical proximity correction, Metals, Oxides, Back end of line, Extreme ultraviolet, Photomasks, Etching, Resistance, Photoresist materials, Extreme ultraviolet lithography, Calibration, Data modeling, Semiconducting wafers, Metrology, Finite element methods

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Proceedings Article | 25 March 2016 Paper

A physical resist shrinkage model for full-chip lithography simulations

Peng Liu, Leiwu Zheng, Maggie Ma, Qian Zhao, Yongfa Fan, Qiang Zhang, Mu Feng, Xin Guo, Tom Wallow, Keith Gronlund, Ronald Goossens, Gary Zhang, Yenwen Lu

Proceedings Volume 9779, 97790Y (2016) https://doi.org/10.1117/12.2239243

KEYWORDS: Lithography, Computational lithography, Photoresist processing, Data modeling, Calibration, Cadmium, 3D modeling, Computer simulations, Optical proximity correction, Semiconducting wafers

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SPIE Journal Paper | 2 April 2015

Subresolution assist features in extreme ultraviolet lithography

Deniz Civay, Erik Verduijn, Chris Clifford, Pawitter Mangat, Thomas Wallow

JM3, Vol. 14, Issue 02, 023501, (April 2015) https://doi.org/10.1117/12.10.1117/1.JMM.14.2.023501

KEYWORDS: SRAF, Photomasks, Extreme ultraviolet, Printing, Semiconducting wafers, Extreme ultraviolet lithography, Critical dimension metrology, Model-based design, Lithography, Optical lithography

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Proceedings Article | 17 April 2014 Paper

Deconstructing contact hole CD printing variability in EUV lithography

D. Civay, T. Wallow, N. Doganaksoy, E. Verduijn, G. Schmid, P. Mangat

Proceedings Volume 9048, 90483D (2014) https://doi.org/10.1117/12.2049546

KEYWORDS: Photomasks, Stochastic processes, SRAF, Critical dimension metrology, Semiconducting wafers, Extreme ultraviolet, Optical lithography, Extreme ultraviolet lithography, Metrology, Printing

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Proceedings Article | 18 March 2014 Paper

EUV OPC modeling and correction requirements

Tamer Coskun, Tom Wallow, Gek Soon Chua, Keith Standiford, Craig Higgins, Yi Zou

Proceedings Volume 9048, 90480W (2014) https://doi.org/10.1117/12.2046341

KEYWORDS: Photomasks, 3D modeling, Optical proximity correction, Data modeling, Extreme ultraviolet, Calibration, Semiconducting wafers, Critical dimension metrology, Extreme ultraviolet lithography, Data processing

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Proceedings Article | 10 April 2013 Paper

Evaluating scatterometry 3D capabilities for EUV

Jie Li, Oleg Kritsun, Prasad Dasari, Catherine Volkman, Tom Wallow, Jiangtao Hu

Proceedings Volume 8681, 86810S (2013) https://doi.org/10.1117/12.2011675

KEYWORDS: Semiconducting wafers, Scatterometry, Metrology, Extreme ultraviolet, Critical dimension metrology, Extreme ultraviolet lithography, 3D metrology, Neodymium, Spectroscopic ellipsometry, Lithography

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Proceedings Article | 1 April 2013 Paper

Application of phase shift focus monitor in EUVL process control

Lei Sun, Sudhar Raghunathan, Vibhu Jindal, Eric Gullikson, Pawitter Mangat, Iacopo Mochi, Kenneth Goldberg, Markus Benk, Oleg Kritsun, Tom Wallow, Deniz Civay, Obert Wood

Proceedings Volume 8679, 86790T (2013) https://doi.org/10.1117/12.2011342

KEYWORDS: Phase shifts, Extreme ultraviolet lithography, Extreme ultraviolet, Photomasks, Reflectivity, Etching, Diffraction, Diffraction gratings, Inspection, Microscopes

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Proceedings Article | 1 April 2013 Paper

Considerations for high-numerical aperture EUV lithography

Harry Levinson, Pawitter Mangat, Thomas Wallow, Lei Sun, Paul Ackmann, Sheldon Meyers

Proceedings Volume 8679, 867916 (2013) https://doi.org/10.1117/12.2015829

KEYWORDS: Photomasks, Extreme ultraviolet, Semiconducting wafers, Extreme ultraviolet lithography, Reticles, Mask making, Defect inspection, Ions, Scanners, Lithography

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Proceedings Article | 1 April 2013 Paper

7nm node EUV predictive study of mask LER transference to wafer

D. Civay, E. Nash, U. Klostermann, T. Wallow, P. Mangat, H. Koh, P. Brooker, J. Siebert, H. Levinson

Proceedings Volume 8679, 86792Q (2013) https://doi.org/10.1117/12.2011197

KEYWORDS: Line edge roughness, Photomasks, Stochastic processes, Semiconducting wafers, Critical dimension metrology, Calibration, Lithography, Extreme ultraviolet, Extreme ultraviolet lithography, Nanoimprint lithography

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Proceedings Article | 23 March 2012 Paper

Mask shadowing and the line-edge transfer function

Brittany McClinton, Thomas Wallow, Patrick Naulleau

Proceedings Volume 8322, 832221 (2012) https://doi.org/10.1117/12.917790

KEYWORDS: Line edge roughness, Photomasks, Semiconducting wafers, Spatial frequencies, Extreme ultraviolet lithography, Contrast transfer function, Reflectivity, Extreme ultraviolet, Lithographic illumination, Lithography

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Proceedings Article | 23 March 2012 Paper

EUV OPC for the 20-nm node and beyond

Chris Clifford, Yi Zou, Azat Latypov, Oleg Kritsun, Thomas Wallow, Harry Levinson, Fan Jiang, Deniz Civay, Keith Standiford, Ralph Schlief, Lei Sun, Obert Wood, Sudhar Raghunathan, Pawitter Mangat, Hui Peng Koh, Craig Higgins, Jeffrey Schefske, Mandeep Singh

Proceedings Volume 8322, 83221M (2012) https://doi.org/10.1117/12.916171

KEYWORDS: Optical proximity correction, Extreme ultraviolet, Photomasks, Deep ultraviolet, Semiconducting wafers, Extreme ultraviolet lithography, Lithography, Critical dimension metrology, Printing, Monte Carlo methods

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Proceedings Article | 23 March 2012 Paper

EUV resist performance: current assessment for sub-22-nm half-pitch patterning on NXE:3300

T. Wallow, D. Civay, S. Wang, H. F. Hoefnagels, C. Verspaget, G. Tanriseven, A. Fumar-Pici, S. Hansen, J. Schefske, M. Singh, R. Maas, Y. van Dommelen, J. Mallman

Proceedings Volume 8322, 83221J (2012) https://doi.org/10.1117/12.918039

KEYWORDS: Line width roughness, Extreme ultraviolet, Optical lithography, Critical dimension metrology, Extreme ultraviolet lithography, Stochastic processes, Lithography, Data modeling, Cadmium, Photoresist processing

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Proceedings Article | 23 March 2012 Paper

Computational study of line tip printability of sub-20-nm technology

Lei Yuan, Thomas Wallow, Deniz Civay, Linus Jang, Jongwook Kye, Harry Levinson, Sohan Singh, Mark Kelling

Proceedings Volume 8322, 832229 (2012) https://doi.org/10.1117/12.915868

KEYWORDS: Printing, Extreme ultraviolet, Optical lithography, Lithography, Extreme ultraviolet lithography, Photomasks, Lithographic illumination, Double patterning technology, Line edge roughness, Metals

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Proceedings Article | 14 March 2012 Paper

Insertion strategy for EUV lithography

Obert Wood, John Arnold, Timothy Brunner, Martin Burkhardt, James H.-C. Chen, Deniz Civay, Susan S.-C. Fan, Emily Gallagher, Scott Halle, Ming He, Craig Higgins, Hirokazu Kato, Jongwook Kye, Chiew-Seng Koay, Guillaume Landie, Pak Leung, Gregory McIntyre, Satoshi Nagai, Karen Petrillo, Sudhar Raghunathan, Ralph Schlief, Lei Sun, Alfred Wagner, Tom Wallow, Yunpeng Yin, Xuelian Zhu, Matthew Colburn, Daniel Corliss, Cecilia Smolinski

Proceedings Volume 8322, 832203 (2012) https://doi.org/10.1117/12.916292

KEYWORDS: Extreme ultraviolet lithography, Extreme ultraviolet, Photomasks, Manufacturing, Lithography, Immersion lithography, Optical lithography, Metals, Semiconducting wafers, Overlay metrology

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Proceedings Article | 20 April 2011 Paper

EUV defect characterization study on post litho and etch for 1x and 2x node processes

Ofir Montal, Man-Ping Cai, Kfir Dotan, Ido Dolev, Tom Wallow, Obert Wood, Uzo Okoroanyanwu, Moshe Rozentsvige, Chris Ngai, Chris Bencher, Amiad Conley

Proceedings Volume 7971, 797126 (2011) https://doi.org/10.1117/12.881518

KEYWORDS: Etching, Extreme ultraviolet, Semiconducting wafers, Lithography, Deep ultraviolet, Scattering, Polarization, Bridges, Inspection, Light scattering

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Proceedings Article | 16 April 2011 Paper

Revisit pattern collapse for 14nm node and beyond

Kenji Yoshimoto, Craig Higgins, Ananthan Raghunathan, John Hartley, Dario Goldfarb, Hirokazu Kato, Karen Petrillo, Matthew Colburn, Jeffrey Schefske, Obert Wood, Thomas Wallow

Proceedings Volume 7972, 79720K (2011) https://doi.org/10.1117/12.880180

KEYWORDS: Extreme ultraviolet, Extreme ultraviolet lithography, Capillaries, Semiconducting wafers, Photoresist processing, Data modeling, Scanning electron microscopy, Glasses, Electron beam lithography, Lithography

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Proceedings Article | 8 April 2011 Paper

Absorber height effects on SWA restrictions and shadow LER

Brittany McClinton, Patrick Naulleau, Thomas Wallow

Proceedings Volume 7969, 796920 (2011) https://doi.org/10.1117/12.882266

KEYWORDS: Line edge roughness, Photomasks, Semiconducting wafers, Spatial frequencies, Extreme ultraviolet lithography, Extreme ultraviolet, Tolerancing, Lithography, Reflectivity, Contrast transfer function

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Proceedings Article | 8 April 2011 Paper

Photoresist shrinkage effects at EUV

Thomas Pistor, Thomas Wallow, Christopher Anderson, Patrick Naulleau

Proceedings Volume 7969, 796917 (2011) https://doi.org/10.1117/12.879554

KEYWORDS: Distortion, Extreme ultraviolet lithography, 3D modeling, Photoresist materials, Extreme ultraviolet, Lithography, Silicon, Lanthanum, Current controlled current source, Electron beams

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Proceedings Article | 6 April 2011 Paper

EUV masks under exposure: practical considerations

Emily Gallagher, Gregory McIntyre, Tom Wallow, Sudharshanan Raghunathan, Obert Wood, Louis Kindt, John Whang, Monica Barrett

Proceedings Volume 7969, 79690W (2011) https://doi.org/10.1117/12.880755

KEYWORDS: Photomasks, Semiconducting wafers, Line edge roughness, Critical dimension metrology, Extreme ultraviolet lithography, Particles, Reflectivity, Extreme ultraviolet, Manufacturing, Ruthenium

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Proceedings Article | 6 April 2011 Paper

EUV OPC for 56nm metal pitch

Martin Burkhardt, Matt Colburn, Yunfei Deng, Emily Gallagher, Hirokazu Kato, Greg McIntyre, Karen Petrillo, Sudhar Raghunathan, Adam Smith, Tom Wallow, Obert Wood, Yi Zou, Christian Zuniga

Proceedings Volume 7969, 79690U (2011) https://doi.org/10.1117/12.879931

KEYWORDS: Photomasks, Optical proximity correction, Calibration, Back end of line, Extreme ultraviolet, Extreme ultraviolet lithography, Scanning electron microscopy, Printing, Photoresist processing, Distortion

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Proceedings Article | 5 April 2011 Paper

The SEMATECH Berkeley MET: extending EUV learning down to 16nm half pitch

Christopher Anderson, Lorie Mae Baclea-An, Paul Denham, Simi George, Kenneth Goldberg, Michael Jones, Nathan Smith, Thomas Wallow, Warren Montgomery, Patrick Naulleau

Proceedings Volume 7969, 79690R (2011) https://doi.org/10.1117/12.881573

KEYWORDS: Printing, Illumination engineering, Metals, Oxides, Extreme ultraviolet, Chemically amplified resists, Image resolution, Optical lithography, Phase shifts, Modulation

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Proceedings Article | 2 April 2011 Paper

Using synchrotron light to accelerate EUV resist and mask materials learning

Patrick Naulleau, Christopher Anderson, Lorie-Mae Baclea-an, Paul Denham, Simi George, Kenneth Goldberg, Gideon Jones, Brittany McClinton, Ryan Miyakawa, Iacopo Mochi, Warren Montgomery, Seno Rekawa, Tom Wallow

Proceedings Volume 7985, 798509 (2011) https://doi.org/10.1117/12.885420

KEYWORDS: Extreme ultraviolet lithography, Line edge roughness, Extreme ultraviolet, Photomasks, Synchrotrons, Light sources, Printing, Chemically amplified resists, Image resolution, Imaging systems

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Proceedings Article | 25 September 2010 Paper

A lifetime study of EUV masks

Emily Gallagher, Obert Wood, Louis Kindt, Hirokazu Kato, Uzodinma Okoroanyanwu, John Whang, Monica Barrett, Tom Wallow

Proceedings Volume 7823, 78231L (2010) https://doi.org/10.1117/12.864948

KEYWORDS: Photomasks, Extreme ultraviolet, Inspection, Semiconducting wafers, Extreme ultraviolet lithography, Ruthenium, Reflectivity, Particles, Scatterometry, Metrology

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Proceedings Article | 23 March 2010 Paper

The SEMATECH Berkeley MET pushing EUV development beyond 22nm half pitch

Patrick Naulleau, Christopher Anderson, Lorie-Mae Baclea-an, David Chan, Paul Denham, Simi George, Kenneth Goldberg, Brian Hoef, Gideon Jones, Chawon Koh, Bruno La Fontaine, Brittany McClinton, Ryan Miyakawa, Warren Montgomery, Seno Rekawa, Tom Wallow

Proceedings Volume 7636, 76361J (2010) https://doi.org/10.1117/12.848438

KEYWORDS: Line edge roughness, Photomasks, Extreme ultraviolet, Printing, Phase shifts, Lithographic illumination, Extreme ultraviolet lithography, Image resolution, Mask cleaning, Resolution enhancement technologies

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Proceedings Article | 23 March 2010 Paper

Analysis and characterization of contamination in EUV reticles

Uzodinma Okoroanyanwu, Kornelia Dittmar, Torsten Fahr, Tom Wallow, Bruno La Fontaine, Obert Wood, Christian Holfeld, Karsten Bubke, Jan-Hendrik Peters

Proceedings Volume 7636, 76361Y (2010) https://doi.org/10.1117/12.847269

KEYWORDS: Reticles, Contamination, Reflectivity, Extreme ultraviolet lithography, Extreme ultraviolet, Chemical analysis, Carbon, Raman spectroscopy, Spectroscopy, Thin films

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A host of complementary imaging techniques (Scanning Electron Microscopy), surface analytical technique (Auger Electron Spectroscopy, AES), chemical analytical and speciation techniques (Grazing Incidence Reflectance Fourier-Transform Infrared Spectroscopy, GIR-FTIR; and Raman spectroscopy) have been assessed for their sensitivity and effectiveness in analyzing contamination on three EUV reticles that were contaminated to varying degrees. The first reticle was contaminated as a result of its exposure experience on the SEMATECH EUV Micro Exposure Tool (MET) at Lawrence Berkeley National Laboratories, where it was exposed to up to 80 hours of EUV radiation. The second reticle was a full-field reticle, specifically designed to monitor molecular contamination, and exposed to greater than 1600J/cm² of EUV radiation on the ASML Alpha Demo Tool (ADT) in Albany Nanotech in New York. The third reticle was intentionally contaminated with hydrocarbons in the Microscope for Mask Imaging and Contamination Studies (MIMICS) tool at the College of Nanoscale Sciences of State University of New York at Albany. The EUV reflectivities of some of these reticles were measured on the Advanced Light Source EUV Reflectomer at Lawrence Berkeley National Laboratories and PTB Bessy in Berlin, respectively. Analysis and characterization of thin film contaminants on the two EUV reticles exposed to varying degrees of EUV radiation in both MET and ADT confirm that the two most common contamination types are carbonization and surface oxidation, mostly on the exposed areas of the reticle, and with the MET being significantly more susceptible to carbon contamination than the ADT. While AES in both surface scanning and sputter mode is sensitive and efficient in analyzing thin contaminant films (of a few nanometers), GIRFTIR is sensitive to thick films (of order of a 100 nm or more on non-infra-red reflecting substrates), Raman spectroscopy is not compatible with analyzing such contaminants because of laser-induced evaporation of the contaminant film. SEM and EUV reflectometry are effective in quantifying the impact of contamination on imaging performance and reflectivity, respectively.

Proceedings Article | 23 March 2010 Paper

EUV lithography at the 22nm technology node

Obert Wood, Chiew-Seng Koay, Karen Petrillo, Hiroyuki Mizuno, Sudhar Raghunathan, John Arnold, Dave Horak, Martin Burkhardt, Gregory McIntyre, Yunfei Deng, Bruno La Fontaine, Uzo Okoroanyanwu, Tom Wallow, Guillaume Landie, Theodorus Standaert, Sean Burns, Christopher Waskiewicz, Hirohisa Kawasaki, James H.-C. Chen, Matthew Colburn, Bala Haran, Susan S.-C. Fan, Yunpeng Yin, Christian Holfeld, Jens Techel, Jan-Hendrik Peters, Sander Bouten, Brian Lee, Bill Pierson, Bart Kessels, Robert Routh, Kevin Cummings

Proceedings Volume 7636, 76361M (2010) https://doi.org/10.1117/12.847049

KEYWORDS: Extreme ultraviolet lithography, Extreme ultraviolet, Photomasks, Immersion lithography, Double patterning technology, Optical proximity correction, Printing, Lithography, Optical lithography, Metals

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Proceedings Article | 20 March 2010 Paper

Resist pattern prediction at EUV

John Biafore, Mark Smith, Eelco van Setten, Tom Wallow, Patrick Naulleau, David Blankenship, Stewart Robertson, Yunfei Deng

Proceedings Volume 7636, 76360R (2010) https://doi.org/10.1117/12.846535

KEYWORDS: Extreme ultraviolet, Line width roughness, Absorption, Ionization, Stochastic processes, Molecules, Scattering, Data modeling, Critical dimension metrology, Extreme ultraviolet lithography

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Proceedings Article | 18 March 2010 Paper

Characterization of line-edge roughness (LER) propagation from resists: underlayer interfaces in ultrathin resist films

Simi George, Patrick Naulleau, Ahila Krishnamoorthy, Zeyu Wu, Edward Rutter, Joseph Kennedy, Song Yuan Xie, Kyle Flanigan, Thomas Wallow

Proceedings Volume 7636, 763605 (2010) https://doi.org/10.1117/12.848405

KEYWORDS: Line edge roughness, Interfaces, Thin films, Photoresist materials, Extreme ultraviolet lithography, Extreme ultraviolet, 3D image processing, Photoresist processing, Head-mounted displays, Liquids

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Proceedings Article | 13 March 2010 Paper

Comparative study of line width roughness (LWR) in next-generation lithography (NGL) processes

Kedar Patel, Thomas Wallow, Harry Levinson, Costas Spanos

Proceedings Volume 7640, 76400T (2010) https://doi.org/10.1117/12.848183

KEYWORDS: Line width roughness, Lithography, Extreme ultraviolet, Etching, Scanning electron microscopy, Nanoimprint lithography, Line edge roughness, Image processing, Photoresist processing, Directed self assembly

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Proceedings Article | 11 December 2009 Paper

High Si content anti-reflective coatings and their extension to a UV freeze dual patterning process

Joseph Kennedy, ZeYu Wu, Kyle Flanigan, Junyan Dai, Thomas Wallow

Proceedings Volume 7520, 75200O (2009) https://doi.org/10.1117/12.837205

KEYWORDS: Ultraviolet radiation, Photoresist materials, Optical lithography, Semiconducting wafers, Silicon, Double patterning technology, Optical properties, Lithography, Photoresist developing, Chemistry

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Proceedings Article | 11 December 2009 Paper

Pattern prediction in EUV resists

John Biafore, Mark Smith, Tom Wallow, Patrick Nalleau, David Blankenship, Yunfei Deng

Proceedings Volume 7520, 75201P (2009) https://doi.org/10.1117/12.836910

KEYWORDS: Extreme ultraviolet, Ionization, Absorption, Stochastic processes, Scattering, Line width roughness, Absorbance, Data modeling, Molecules, Extreme ultraviolet lithography

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Proceedings Article | 1 April 2009 Paper

Performance of an ArF siloxane BARC exposed to a 172-nm UV cure for double patterning applications

Ze-Yu Wu, Joseph Kennedy, Song-Yuan Xie, Ron Katsanes, Kyle Flanigan, Junyan Dai, Nikolaos Bekiaris, Hiram Cervera, Glen Mori, Thomas Wallow

Proceedings Volume 7273, 72731I (2009) https://doi.org/10.1117/12.814416

KEYWORDS: Ultraviolet radiation, Photoresist materials, Optical lithography, Semiconducting wafers, Double patterning technology, Silicon, Optical properties, FT-IR spectroscopy, Lithography, Time division multiplexing

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Proceedings Article | 1 April 2009 Paper

Correlation of experimental and simulated cure-induced photoresist distortions in double patterning

Thomas Wallow, Mahidhar Rayasam, Masanori Yamaguchi, Yohei Yamada, Karen Petrillo, Kenji Yoshimoto, Jongwook Kye, Ryoung-Han Kim, Harry Levinson

Proceedings Volume 7273, 727309 (2009) https://doi.org/10.1117/12.814474

KEYWORDS: Double patterning technology, Photoresist materials, Finite element methods, Scanning electron microscopy, Photoresist processing, Metrology, Etching, Lithography, Ultraviolet radiation, Photoresist developing

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Proceedings Article | 1 April 2009 Paper

Photoresist stabilization for double patterning using 172 nm photoresist curing

Thomas Wallow, Junyan Dai, Charles Szmanda, Hiram Cervera, Chi Truong, Nikolaos Bekiaris, Jong-Wook Kye, Ryoung-Han Kim, Harry Levinson, Glen Mori

Proceedings Volume 7273, 72730D (2009) https://doi.org/10.1117/12.814468

KEYWORDS: Photoresist processing, Semiconducting wafers, Double patterning technology, Ultraviolet radiation, Photoresist materials, Image processing, Optical lithography, Lithography, Fourier transforms, Antireflective coatings

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Proceedings Article | 1 April 2009 Paper

Correlation of EUV resist performance metrics in micro-exposure and full-field EUV projection tools

Thomas Wallow, Bill Pierson, Hiroyuki Mizuno, Anita Fumar-Pici, Karen Petrillo, Chris Anderson, Patrick Naulleau, Steven Hansen, Yunfei Deng, Koen van Ingen Schenau, Chiew-Seng Koay, Linda Ohara, Sang-In Han, Robert Watso, Lior Huli, Martin Burkhardt, Obert Wood, Joerg Mallmann, Bart Kessels, Robert Routh, Kevin Cummings

Proceedings Volume 7273, 72733T (2009) https://doi.org/10.1117/12.814457

KEYWORDS: Optical proximity correction, Extreme ultraviolet lithography, Extreme ultraviolet, Data modeling, Lithography, Diagnostics, Photoresist processing, Nanoimprint lithography, Diffusion, Reticles

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Proceedings Article | 18 March 2009 Paper

The SEMATECH Berkeley microfield exposure tool: learning at the 22-nm node and beyond

Patrick Naulleau, Christopher Anderson, Lorie-Mae Baclea-an, Paul Denham, Simi George, Kenneth Goldberg, Michael Goldstein, Brian Hoef, Russ Hudyma, Gideon Jones, Chawon Koh, Bruno La Fontaine, Brittany McClinton, Ryan Miyakawa, Warren Montgomery, John Roller, Thomas Wallow, Stefan Wurm

Proceedings Volume 7271, 72710W (2009) https://doi.org/10.1117/12.814232

KEYWORDS: Line edge roughness, Photomasks, Extreme ultraviolet, Extreme ultraviolet lithography, Semiconducting wafers, Printing, Lithography, Computer aided design, Synchrotrons, Surface roughness

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Proceedings Article | 18 March 2009 Paper

Exposure tool settings and OPC strategies for EUV lithography at the 16-nm node

Yunfei Deng, Jongwook Kye, Bruno La Fontaine, Tom Wallow, Obert Wood, Harry Levinson, Anita Fumar-Pici, Hiroyuki Mizuno, Chiew-seng Koay, Greg McIntyre

Proceedings Volume 7271, 727119 (2009) https://doi.org/10.1117/12.814953

KEYWORDS: Critical dimension metrology, Optical proximity correction, Extreme ultraviolet lithography, Extreme ultraviolet, EUV optics, Diffusion, Lithographic illumination, Photomasks, Image processing, Semiconducting wafers

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Proceedings Article | 18 March 2009 Paper

Assessment of EUV resist readiness for 32-nm hp manufacturing and extendibility study of EUV ADT using state-of-the-art resist

Chawon Koh, Liping Ren, Jacque Georger, Frank Goodwin, Stefan Wurm, Bill Pierson, Joo-On Park, Tom Wallow, Todd Younkin, Patrick Naulleau

Proceedings Volume 7271, 727124 (2009) https://doi.org/10.1117/12.814314

KEYWORDS: Semiconducting wafers, Manufacturing, Extreme ultraviolet lithography, Extreme ultraviolet, Line width roughness, Photoresist processing, Optical lithography, Photomasks, Electroluminescence, Critical dimension metrology

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Proceedings Article | 18 March 2009 Open Access

Integration of EUV lithography in the fabrication of 22-nm node devices

Proceedings Volume 7271, 727104 (2009) https://doi.org/10.1117/12.814379

KEYWORDS: Extreme ultraviolet lithography, Extreme ultraviolet, Photomasks, Semiconducting wafers, Etching, Optical lithography, Photoresist processing, Lithography, Imaging systems, Copper

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SPIE Journal Paper | 1 January 2009

Cure-induced photoresist distortions in double patterning

Thomas Wallow, Mahidhar Rayasam, Masanori Yamaguchi, Yohei Yamada, Ryoung-Han Kim, Jongwook Kye, Harry Levinson

JM3, Vol. 8, Issue 01, 011010, (January 2009) https://doi.org/10.1117/12.10.1117/1.3094746

KEYWORDS: Double patterning technology, Photoresist materials, Finite element methods, Photoresist processing, Scanning electron microscopy, Etching, Lithography, Optical lithography, Ultraviolet radiation, Image analysis

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Proceedings Article | 17 October 2008 Paper

An investigation of EUV lithography defectivity

Kevin Cummings, Thomas Laursen, Bill Pierson, Sang-in Han, Robert Watso, Youri van Dommelen, Brian Lee, Yunfei Deng, Bruno La Fontaine, Thomas Wallow, Uzo Okoroanyanwu, Obert Wood, Anna Tchikoulaeva, Christian Holfeld, Jan Hendrick Peters, Chiew-seng Koay, Karen Petrillo, Tony DiBiase, Sumanth Kini, Hiroyuki Mizuno

Proceedings Volume 7122, 71222G (2008) https://doi.org/10.1117/12.801528

KEYWORDS: Photomasks, Semiconducting wafers, Reticles, Extreme ultraviolet lithography, Inspection, Particles, Scanning electron microscopy, Wafer inspection, Defect inspection, Silicon

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Proceedings Article | 15 April 2008 Paper

A lithographic and process assessment of photoresist stabilization for double-patterning using 172-nm photoresist curing

Nikolaos Bekiaris, Hiram Cervera, Junyan Dai, Ryoung-han Kim, Alden Acheta, Thomas Wallow, Jongwook Kye, Harry Levinson, Thomas Nowak, James Yu

Proceedings Volume 6923, 692321 (2008) https://doi.org/10.1117/12.774205

KEYWORDS: Photoresist processing, Photoresist materials, Double patterning technology, Ultraviolet radiation, Floods, Lithography, Semiconducting wafers, Optical lithography, Coating, Printing

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Proceedings Article | 3 April 2008 Paper

Advanced extreme ultraviolet resist testing using the SEMATECH Berkeley 0.3-NA microfield exposure tool

Patrick Naulleau, Christopher Anderson, Jerrin Chiu, Kim Dean, Paul Denham, Kenneth Goldberg, Brian Hoef, Sungmin Huh, Gideon Jones, Bruno LaFontaine, Andy Ma, Dimitra Niakoula, Joo-on Park, Tom Wallow

Proceedings Volume 6921, 69213N (2008) https://doi.org/10.1117/12.773833

KEYWORDS: Line edge roughness, Monochromatic aberrations, Extreme ultraviolet, Photomasks, Printing, Lithography, Extreme ultraviolet lithography, Semiconducting wafers, Projection systems, Wafer-level optics

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Proceedings Article | 26 March 2008 Paper

The use of EUV lithography to produce demonstration devices

Bruno LaFontaine, Yunfei Deng, Ryoung-Han Kim, Harry Levinson, Sarah McGowan, Uzodinma Okoroanyanwu, Rolf Seltmann, Cyrus Tabery, Anna Tchikoulaeva, Tom Wallow, Obert Wood, John Arnold, Don Canaperi, Matthew Colburn, Kurt Kimmel, Chiew-Seng Koay, Erin Mclellan, Dave Medeiros, Satyavolu Papa Rao, Karen Petrillo, Yunpeng Yin, Hiroyuki Mizuno, Sander Bouten, Michael Crouse, Andre van Dijk, Youri van Dommelen, Judy Galloway, Sang-In Han, Bart Kessels, Brian Lee, Sjoerd Lok, Brian Niekrewicz, Bill Pierson, Robert Routh, Emil Schmit-Weaver, Kevin Cummings, James Word

Proceedings Volume 6921, 69210P (2008) https://doi.org/10.1117/12.772933

KEYWORDS: Extreme ultraviolet lithography, Photomasks, Semiconducting wafers, Transistors, Extreme ultraviolet, Optical proximity correction, Photoresist processing, Etching, Metals, Scanners

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Proceedings Article | 20 March 2008 Paper

Evaluation of EUV resist materials for use at the 32 nm half-pitch node

Thomas Wallow, Craig Higgins, Robert Brainard, Karen Petrillo, Warren Montgomery, Chiew-Seng Koay, Greg Denbeaux, Obert Wood, Yayi Wei

Proceedings Volume 6921, 69211F (2008) https://doi.org/10.1117/12.772943

KEYWORDS: Extreme ultraviolet, Optical lithography, Extreme ultraviolet lithography, Line edge roughness, Lithography, Interferometers, Photoresist materials, High volume manufacturing, Printing, Image resolution

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Proceedings Article | 3 May 2007 Paper

Progress in EUV photoresist technology

Thomas Wallow, Ryoung-han Kim, Bruno LaFontaine, Patrick Naulleau, Chris Anderson, Richard Sandberg

Proceedings Volume 6533, 653317 (2007) https://doi.org/10.1117/12.737189

KEYWORDS: Extreme ultraviolet, Line width roughness, Extreme ultraviolet lithography, Photoresist processing, Modulation transfer functions, Diffusion, Point spread functions, Line edge roughness, Cadmium sulfide, Photoresist technology

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Resist resolution remains a significant issue for EUV. Strong concerns persist regarding the use of chemically amplified resists owing to their diffusion characteristics. Current EUV resist development is focused on a) large-scale screening efforts in an attempt to identify promising platforms and b) refinement and optimization of the processing of these formulations. Resolution arguably remains the parameter of highest importance at this time. The intrinsic resist resolution limit has been claimed to be determined by the resist diffusion length and various metrics have been proposed to characterize this diffusion length as well as resist resolution. Characterization of the intrinsic resolution limit of resists, however, is not a trivial issue due to practical complications such as pattern collapse and top-loss. Here we investigate a variety of resolution and diffusion length metrics and study the correlation between these metrics and observed resist performance when applied to a variety of leading EUV resists. The metrics we study include resist modulation transfer function, corner rounding, through-dose sub-resolution contact printing, iso-focal bias, line-edge-roughness correlation length, and mask error factor. We present an analogous study of resist process refinements. Process refinements are capable of significantly enhancing resolution, expanding process latitude, mitigating resist failure mechanisms, and attenuating line-edge and line-width roughness. Metrics used for correlation of resolution and diffusion length with resist performance show significant utility when applied to process refinement studies as well. Additionally, we show that LWR mitigation can be accomplished in selected EUV resists using post-development surface conditioner rinses. A similar post-development rinse apprach is also demonstrated to reduce pattern collapse at sub-40 nm CDs. Such strategies may become increasingly attractive as CDs shrink toward 32 nm and 22 nm nodes.

Proceedings Article | 11 April 2007 Paper

Line-edge roughness in 193-nm resists: lithographic aspects and etch transfer

Thomas Wallow, Alden Acheta, Yuansheng Ma, Adam Pawloski, Scott Bell, Brandon Ward, Cyrus Tabery, Bruno La Fontaine, Ryoung-han Kim, Sarah McGowan, Harry Levinson

Proceedings Volume 6519, 651919 (2007) https://doi.org/10.1117/12.712319

KEYWORDS: Line edge roughness, Etching, Photoresist materials, Spatial frequencies, Lithography, Smoothing, Image processing, Critical dimension metrology, Semiconducting wafers, Photoresist processing

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Proceedings Article | 5 April 2007 Paper

Line edge roughness impact on critical dimension variation

Yuansheng Ma, Harry Levinson, Thomas Wallow

Proceedings Volume 6518, 651824 (2007) https://doi.org/10.1117/12.712388

KEYWORDS: Critical dimension metrology, Line edge roughness, Fractal analysis, Etching, Monte Carlo methods, Scanning electron microscopy, Transistors, Line width roughness, Fourier transforms, Spatial frequencies

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Proceedings Article | 26 March 2007 Paper

Double exposure using 193-nm negative tone photoresist

Ryoung-han Kim, Tom Wallow, Jongwook Kye, Harry Levinson, Dave White

Proceedings Volume 6520, 65202M (2007) https://doi.org/10.1117/12.713209

KEYWORDS: Photomasks, Double patterning technology, Line edge roughness, Lithography, Photoresist materials, Etching, Optical lithography, Scanning electron microscopy, Image resolution, Resolution enhancement technologies

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Proceedings Article | 22 March 2007 Paper

Characterization of photo-acid redeposition in 193-nm photoresists

Thomas Wallow, Marina Plat, Zhanping Zhang, Brian MacDonald, Joffre Bernard, Jeremias Romero, Bruno La Fontaine, Harry Levinson

Proceedings Volume 6519, 65190T (2007) https://doi.org/10.1117/12.712338

KEYWORDS: Photoresist materials, Ions, Lithography, Image resolution, Chemical analysis, Bismuth, Photoresist processing, Photoresist developing, Raster graphics, Lead

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Proceedings Article | 20 March 2007 Paper

Lithographic metrics for the determination of intrinsic resolution limits in EUV resists

Patrick Naulleau, Christopher Anderson, Bruno La Fontaine, Ryoung-han Kim, Tom Wallow

Proceedings Volume 6517, 65172N (2007) https://doi.org/10.1117/12.712363

KEYWORDS: Extreme ultraviolet, Point spread functions, Line edge roughness, Modulation transfer functions, Diffusion, Lithography, Extreme ultraviolet lithography, Photoresist processing, Printing, Chemically amplified resists

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Proceedings Article | 15 March 2007 Paper

Recent results from the Berkeley 0.3-NA EUV microfield exposure tool

Patrick Naulleau, Chris Anderson, Kim Dean, Paul Denham, Kenneth Goldberg, Brian Hoef, Bruno La Fontaine, Tom Wallow

Proceedings Volume 6517, 65170V (2007) https://doi.org/10.1117/12.713440

KEYWORDS: Monochromatic aberrations, Line edge roughness, Extreme ultraviolet lithography, Extreme ultraviolet, Fiber optic illuminators, Lithography, Line width roughness, Eye, Critical dimension metrology, Photomasks

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Proceedings Article | 15 March 2007 Paper

Initial experience establishing an EUV baseline lithography process for manufacturability assessment

O. Wood, D. Back, R. Brainard, G. Denbeaux, D. Goldfarb, F. Goodwin, J. Hartley, K. Kimmel, C. Koay, B. La Fontaine, J. Mackey, B. Martinick, W. Montgomery, P. Naulleau, U. Okoroanyanwu, K. Petrillo, B. Pierson, M. Tittnich, S. Trogisch, T. Wallow, Y. Wei

Proceedings Volume 6517, 65170U (2007) https://doi.org/10.1117/12.714016

KEYWORDS: Extreme ultraviolet lithography, Extreme ultraviolet, Reticles, Photomasks, Contamination, Reflectivity, Microscopes, Image resolution, Manufacturing, Lithography

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Proceedings Article | 29 March 2006 Paper

Post-etch LER performance of novel surface conditioner solutions

P. Zhang, M. Jaramillo, S. Cassel, T. Wallow, A. Acheta, A. Pawloski, S. Bell, R. Kim

Proceedings Volume 6153, 61533Y (2006) https://doi.org/10.1117/12.656648

KEYWORDS: Line edge roughness, Etching, Semiconducting wafers, Line width roughness, Photoresist processing, Lithography, Plasma, Critical dimension metrology, Scanning electron microscopy, Plasma etching

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Proceedings Article | 29 March 2006 Paper

The transfer of photoresist LER through etch

Adam Pawloski, Alden Acheta, Scott Bell, Bruno La Fontaine, Tom Wallow, Harry Levinson

Proceedings Volume 6153, 615318 (2006) https://doi.org/10.1117/12.652206

KEYWORDS: Line edge roughness, Etching, Photoresist processing, Photoresist materials, Scanning electron microscopy, Image processing, Image quality, Nickel, Semiconducting wafers, Optical lithography

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Proceedings Article | 23 January 2006 Paper

Injection molded microfluidic devices for biological sample separation and detection

Alfredo Morales, Blake Simmons, Thomas Wallow, K. Jeffery Campbell, Seethambal Mani, Brita Mittal, Robert Crocker, Eric Cummings, Rafael Davalos, Linda Domeier, Marion Hunter, Karen Krafcik, Gregory McGraw, Bruce Mosier, Shane Sickafoose

Proceedings Volume 6109, 610901 (2006) https://doi.org/10.1117/12.648135

KEYWORDS: Microfluidics, Particles, Glasses, Polymers, Nickel, Semiconducting wafers, Etching, Dielectrophoresis, Electrodes, Capillaries

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Proceedings Article | 14 May 2004 Paper

193-nm negative resist based on acid-catalyzed elimination of polar molecules

Ratnam Sooriyakumaran, Blake Davis, Carl Larson, Phillip Brock, Richard DiPietro, Thomas Wallow, Eric Connor, Linda Sundberg, Gregory Breyta, Robert Allen, Kaushal Patel, Pushkara Rao Varanasi

Proceedings Volume 5376, (2004) https://doi.org/10.1117/12.536432

KEYWORDS: Polymers, Molecules, Switches, Standards development, Distortion, Photoresist materials, Lithography, Spectroscopy, Photomasks, Photoresist developing

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Proceedings Article | 24 July 2002 Paper

Characterization of the polymer-developer interface in 193-nm photoresist polymers and formulations during dissolution

Thomas Wallow, Wendy Chan, William Hinsberg, Seok-Won Lee

Proceedings Volume 4690, (2002) https://doi.org/10.1117/12.474228

KEYWORDS: Polymers, Resistance, Photoresist materials, Interfaces, Photoresist developing, Solids, Modulation, Standards development, Photoresist processing, Annealing

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Proceedings Article | 24 August 2001 Paper

193-nm single-layer resist materials: total consideration of design, physical properties, and lithographic performances on all major alicyclic platform chemistries

Toru Kajita, Yukio Nishimura, Masafumi Yamamoto, Hiroyuki Ishii, A. Soyano, A. Kataoka, Mark Slezak, Makoto Shimizu, Pushkara Varanasi, G. Jordahamo, Margaret Lawson, R. Chen, William Brunsvold, Wenjie Li, Robert Allen, Hiroshi Ito, Hoa Truong, Thomas Wallow

Proceedings Volume 4345, (2001) https://doi.org/10.1117/12.436833

KEYWORDS: Etching, Monochromatic aberrations, Chemistry, Polymers, Lithography, Polymerization, Resistance, Imaging systems, Surface roughness, Transparency

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Proceedings Article | 23 June 2000 Paper

Dissolution/swelling behavior of cycloolefin polymers in aqueous base

Hiroshi Ito, Robert Allen, Juliann Opitz, Thomas Wallow, Hoa Truong, Donald Hofer, Pushkara Varanasi, George Jordhamo, Saikumar Jayaraman, Richard Vicari

Proceedings Volume 3999, (2000) https://doi.org/10.1117/12.388254

KEYWORDS: Polymers, Polymerization, Carbon, Lithography, Crystals, Semiconducting wafers, Quartz, Absorption, Silicon, Carbonates

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Polycycloolefins prepared by addition polymerization of norbornene derivatives are quite different from hydroxystyrene-based polymers in terms of their interaction with aqueous base. Their dissolution kinetics monitored on a quartz crystal microbalance is not a smooth function of the ratio of the polar to nonpolar functionalities in polymer but abruptly changes from very fast dissolution to massive swelling within a narrow range of composition. The maximum swelling is a function of thickness and the entire film thickness can swell in a few seconds at > 3,000 angstroms/sec or at immeasurably fast rates. The initial concentration of a pendant carboxylic acid in polymer has to be selected to minimize swelling and the concentration of an acid-labile group to induce fast dissolution in the exposed area. Furthermore, swelling which occurs in the partially- exposed regions must be minimized by incorporating a third monomer unit or by adding a dissolution modifying agent (DMA) such as t-butyl cholate. However, the function of DMA which is also acid-labile is quite complex; depending on the matrix polymer composition and its dissolution/swelling behavior, DMA could function as a swelling suppressor or promoter and a carboxylic acid generated by acidolysis of DMA as a dissolution or swelling promoter. Photochemically generated sulfonic acid could also affect the dissolution/swelling behavior. Base hydrolysis of anhydride during development is controlled by the polarity (carboxylic acid concentration) in polymer film, which has been demonstrated in an unequivocal fashion by IR spectroscopy under the condition strongly mimicking the development process and thus could boost development contrast but could hurt performance as well. Thus, incorporation of carboxylic acid in the form of methacrylic acid, for example, in radical copolymerization of norbornene with maleic anhydride must be handled carefully as it would increase the susceptibility of the anhydride hydrolysis and could introduce heterogeneity in the polymer as methacrylic acid is rapidly consumed, producing a terpolymer containing a different molar concentration of norbornene and maleic anhydride (a proof against the commonly believed charge transfer polymerization mechanism).

Proceedings Article | 23 June 2000 Paper

Progress toward developing high-performance 193-nm single-layer positive resist based on functionalized poly(norbornenes)

Pushkara Varanasi, George Jordhamo, Margaret Lawson, K. Rex Chen, William Brunsvold, Timothy Hughes, Robin Keller, Mahmoud Khojasteh, W. Li, Robert Allen, Hiroshi Ito, Juliann Opitz, Hoa Truong, Thomas Wallow

Proceedings Volume 3999, (2000) https://doi.org/10.1117/12.388280

KEYWORDS: Polymers, Etching, Lithography, Reactive ion etching, Surface roughness, Photomasks, 193nm lithography, Phase shifts, Deep ultraviolet, Photoresist materials

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Proceedings Article | 11 June 1999 Paper

Approaches to etch-resistant 193-nm photoresists: performance and prospects

Robert Allen, Juliann Opitz, Hiroshi Ito, Thomas Wallow, Daniel Casmier, Richard Di Pietro, Phillip Brock, Gregory Breyta, Ratnam Sooriyakumaran, Carl Larson, Donald Hofer, Pushkara Varanasi, Ann Mewherter, Saikumar Jayaraman, Richard Vicari, Larry Rhodes, Shenliang Sun

Proceedings Volume 3678, (1999) https://doi.org/10.1117/12.350262

KEYWORDS: Polymers, Polymerization, Etching, Absorbance, Resistance, Photoresist materials, Oxides, Transparency, Lithography, Deep ultraviolet

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Proceedings Article | 11 June 1999 Paper

Development of an incremental structural parameter model for predicting reactive ion etch rates of 193-nm photoresist polymer platforms

Thomas Wallow, Phillip Brock, Richard Di Pietro, Robert Allen, Juliann Opitz, Ratnam Sooriyakumaran, Donald Hofer, Ann Mewherter, Yuping Cui, Wendy Yan, G. Worth, Wayne Moreau, Jeff Meute, Jeff Byers, Georgia Rich, Martin McCallum, Saikumar Jayaraman, Richard Vicari, Joy Cagle, Shenliang Sun, Karen Hullihen

Proceedings Volume 3678, (1999) https://doi.org/10.1117/12.350211

KEYWORDS: Etching, Polymers, Reactive ion etching, Photoresist materials, Oxides, Carbon, Photoresist developing, Chemical species, Ions, Data modeling

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Proceedings Article | 11 June 1999 Paper

Molecular weight tailoring in methacrylate 193-nm photoresists

Thomas Wallow, Phillip Brock, Hoa Truong, Robert Allen, Juliann Opitz, Donald Hofer

Proceedings Volume 3678, (1999) https://doi.org/10.1117/12.350162

KEYWORDS: Polymers, Photoresist materials, Lithography, Glasses, Photoresist developing, Systems modeling, Annealing, Roads, Calcium, Control systems

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Proceedings Article | 11 June 1999 Paper

Design and development of high-performance 193-nm positive resist based on functionalized poly(cyclicolefins)

Pushkara Varanasi, J. Maniscalco, Ann Mewherter, Margaret Lawson, George Jordhamo, Robert Allen, Juliann Opitz, Hiroshi Ito, Thomas Wallow, Donald Hofer, Leah Langsdorf, Saikumar Jayaraman, Richard Vicari

Proceedings Volume 3678, (1999) https://doi.org/10.1117/12.350251

KEYWORDS: Polymers, Etching, Reactive ion etching, 193nm lithography, Lithography, Photoresist processing, Photoresist materials, Semiconductors, Photoresist developing, Absorption

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Proceedings Article | 29 June 1998 Paper

New approaches to production-worthy 193-nm photoresists based on acrylic copolymers

Thomas Wallow, Robert Allen, Juliann Opitz, Richard Di Pietro, Phillip Brock, Ratnam Sooriyakumaran, Donald Hofer

Proceedings Volume 3333, (1998) https://doi.org/10.1117/12.312470

KEYWORDS: Reactive ion etching, Polymers, Etching, Photoresist materials, Resistance, Photoresist developing, Prototyping, Lithography, Solids, Photoresist processing

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Proceedings Article | 29 June 1998 Paper

Lithographic characteristics of 193-nm resists imaged at 193 and 248 nm

Juliann Opitz, Robert Allen, Thomas Wallow, Gregory Wallraff, Donald Hofer

Proceedings Volume 3333, (1998) https://doi.org/10.1117/12.312469

KEYWORDS: Lithography, Polymers, Transparency, 193nm lithography, Photoresist materials, Etching, Absorbance, Reactive ion etching, Photoresist developing, Resistance

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Proceedings Article | 29 June 1998 Paper

Design of an etch-resistant cyclic olefin photoresist

Robert Allen, Juliann Opitz, Thomas Wallow, Richard Di Pietro, Donald Hofer, Saikumar Jayaraman, Karen Hullihan, Larry Rhodes, Brian Goodall, Robert Shick

Proceedings Volume 3333, (1998) https://doi.org/10.1117/12.312472

KEYWORDS: Polymers, Polymerization, Etching, Photoresist materials, Resistance, Deep ultraviolet, Metals, Plasma etching, Lithography, Contamination

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Proceedings Article | 29 June 1998 Paper

Reactive ion etching of 193-nm resist candidates: current platforms and future requirements

Thomas Wallow, Phillip Brock, Richard Di Pietro, Robert Allen, Juliann Opitz, Ratnam Sooriyakumaran, Donald Hofer, Jeff Meute, Jeff Byers, Georgia Rich, Martin McCallum, S. Schuetze, Saikumar Jayaraman, Karen Hullihen, Richard Vicari, Larry Rhodes, Brian Goodall, Robert Shick

Proceedings Volume 3333, (1998) https://doi.org/10.1117/12.312362

KEYWORDS: Etching, Polymers, Reactive ion etching, Oxides, Photoresist materials, Photoresist processing, Carbon, Resistance, Chemical reactions, Control systems

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Proceedings Article | 7 July 1997 Paper

Overview of photoacid generator design for acetal resist systems

Francis Houlihan, Omkaram Nalamasu, Elsa Reichmanis, Allen Timko, Ulrike Varlemann, Thomas Wallow, N. Bantu, John Biafore, Thomas Sarubbi, Pasquale Falcigno, H. Kirner, Norbert Muenzel, Klaus Petschel, Hans-Thomas Schacht, Reinhard Schulz

Proceedings Volume 3049, (1997) https://doi.org/10.1117/12.275848

KEYWORDS: Lithography, Quantum efficiency, Absorbance, Polymers, Microelectronics, Chemically amplified resists, Semiconducting wafers, Chromophores, Silver, Chemistry

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Proceedings Article | 7 July 1997 Paper

Recent advances in 193-nm single-layer photoresists based on alternating copolymers of cycloolefins

Francis Houlihan, Thomas Wallow, Allen Timko, E. Neria, Richard Hutton, Raymond Cirelli, Omkaram Nalamasu, Elsa Reichmanis

Proceedings Volume 3049, (1997) https://doi.org/10.1117/12.275856

KEYWORDS: Polymers, Resistance, Photoresist materials, Lithography, Standards development, Analog electronics, Deep ultraviolet, Spectroscopy, Solids, Scanning electron microscopy

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Proceedings Article | 14 June 1996 Paper

Evaluation of cycloolefin-maleic anhydride alternating copolymers as single-layer photoresists for 193-nm photolithography

Thomas Wallow, Francis Houlihan, Omkaram Nalamasu, Edwin Chandross, Thomas Neenan, Elsa Reichmanis

Proceedings Volume 2724, (1996) https://doi.org/10.1117/12.241834

KEYWORDS: Lithography, Photoresist materials, Distributed interactive simulations, Optical lithography, Resistance, Etching, Polymers, Silicon, Carbon, Deep ultraviolet

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Showing 5 of 86 publications

Proceedings Volume Editor (4)

SPIE Conference Volume | 23 April 2015

Advances in Patterning Materials and Processes XXXII

SPIE Conference Volume | 16 April 2014

Advances in Patterning Materials and Processes XXXI

SPIE Conference Volume | 18 April 2013

Advances in Resist Materials and Processing Technology XXX

SPIE Conference Volume | 27 April 2012

Advances in Resist Materials and Processing Technology XXIX

Conference Committee Involvement (27)

Optical and EUV Nanolithography XXXVII

26 February 2024 | San Jose, California, United States

Optical and EUV Nanolithography XXXVI

27 February 2023 | San Jose, California, United States

Optical and EUV Nanolithography XXXV

25 April 2022 | San Jose, California, United States

Advances in Patterning Materials and Processes XXXIX

25 April 2022 | San Jose, California, United States

Extreme Ultraviolet (EUV) Lithography XII

22 February 2021 | Online Only, California, United States

Advances in Patterning Materials and Processes XXXVIII

22 February 2021 | Online Only, California, United States

Extreme Ultraviolet (EUV) Lithography XI

24 February 2020 | San Jose, California, United States

Advances in Patterning Materials and Processes XXXVII

24 February 2020 | San Jose, California, United States

Extreme Ultraviolet (EUV) Lithography X

25 February 2019 | San Jose, California, United States

Advances in Patterning Materials and Processes XXXVI

25 February 2019 | San Jose, California, United States

Advances in Patterning Materials and Processes XXXV

27 February 2018 | San Jose, California, United States

Extreme Ultraviolet (EUV) Lithography IX

26 February 2018 | San Jose, California, United States

Advances in Patterning Materials and Processes XXXIV

28 February 2017 | San Jose, California, United States

Extreme Ultraviolet (EUV) Lithography VIII

27 February 2017 | San Jose, California, United States

Photomask Technology

12 September 2016 | San Jose, California, United States

Advances in Patterning Materials and Processes XXXIII

29 February 2016 | San Jose, California, United States

Extreme Ultraviolet (EUV) Lithography VII

22 February 2016 | San Jose, California, United States

Advances in Patterning Materials and Processes XXXII

24 February 2015 | San Jose, California, United States

Extreme Ultraviolet (EUV) Lithography VI

23 February 2015 | San Jose, California, United States

Advances in Patterning Materials and Processes XXXI

24 February 2014 | San Jose, California, United States

Extreme Ultraviolet (EUV) Lithography V

24 February 2014 | San Jose, California, United States

Advances in Resist Materials and Processing Technology XXX

25 February 2013 | San Jose, California, United States

Extreme Ultraviolet (EUV) Lithography IV

25 February 2013 | San Jose, California, United States

Extreme Ultraviolet (EUV) Lithography III

13 February 2012 | San Jose, California, United States

Advances in Resist Materials and Processing Technology XXIX

13 February 2012 | San Jose, California, United States

Advances in Resist Materials and Processing Technology XXVIII

28 February 2011 | San Jose, California, United States

Advances in Resist Materials and Processing Technology XXVII

22 February 2010 | San Jose, California, United States

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