Mr. Senajith B. Rekawa Profile

Senajith B. Rekawa

Engineering Manager at Lawrence Berkeley National Lab

SPIE Involvement:

Author

Publications (33)

SPIE Journal Paper | 20 August 2024

Zone plate-based extreme ultraviolet mask microscope with through-pellicle imaging capability

Markus Benk, Dmytro Zaytsev, Chris Orman, Brandon Vollmer, Daniel Santos, Jeffrey Gamsby, Jeremy Mentz, Farhad Salmassi, Arnaud Allezy, Senajith Rekawa, Ryan Miyakawa, Weilun Chao, Eric Gullikson, Scott Chegwidden, Guojing Zhang, Patrick Naulleau, Bruno La Fontaine

JM3, Vol. 23, Issue 04, 041404, (August 2024) https://doi.org/10.1117/12.10.1117/1.JMM.23.4.041404

KEYWORDS: Microscopes, Extreme ultraviolet, Pellicles, Photomasks, Mirrors, Zone plates, Modulation, Imaging systems, Nanoimprint lithography, Microelectromechanical systems

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Proceedings Article | 23 March 2020 Presentation + Paper

Presentation + Paper

How we are making the 0.5-NA Berkeley mirco-field exposure tool stable and productive

Chris Anderson, Arnaud Allezy, Weilun Chao, Lucas Conley, Carl Cork, Will Cork, Rene Delano, Jason DePonte, Michael Dickinson, Geoff Gaines, Jeff Gamsby, Eric Gullikson, Gideon Jones, Lauren McQuade, Ryan Miyakawa, Patrick Naulleau, Seno Rekawa, Farhad Salmassi, Brandon Vollmer, Daniel Zehm, Wenhua Zhu

Proceedings Volume 11323, 113230B (2020) https://doi.org/10.1117/12.2552125

KEYWORDS: Mirrors, Scanners, Semiconducting wafers, Scanning electron microscopy, Camera shutters, Image processing, Vibration isolation, Projection systems

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Proceedings Article | 26 March 2019 Presentation + Paper

Presentation + Paper

Overview and status of the 0.5NA EUV microfield exposure tool at Berkeley Lab

Christopher Anderson, Arnaud Allezy, Weilun Chao, Carl Cork, Will Cork, Rene Delano, Jason DePonte, Michael Dickinson, Geoff Gaines, Jeff Gamsby, Eric Gullikson, Gideon Jones, Stephen Meyers, Ryan Miyakawa, Patrick Naulleau, Senajith Rekawa, Farhad Salmassi, Brandon Vollmer, Daniel Zehm, Wenhua Zhu

Proceedings Volume 10957, 1095708 (2019) https://doi.org/10.1117/12.2516339

KEYWORDS: Scanning electron microscopy, Critical dimension metrology, Semiconducting wafers, Extreme ultraviolet lithography, Optical lithography, Monochromatic aberrations, Line width roughness, Photoresist materials, Image processing, Projection systems

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Proceedings Article | 26 March 2019 Paper

Paper

Achieving diffraction-limited performance on the Berkeley MET5

Ryan Miyakawa, Chris Anderson, Wenhua Zhu, Geoff Gaines, Jeff Gamsby, Carl Cork, Gideon Jones, Michael Dickenson, Seno Rekawa, Weilun Chao, Sharon Oh, Patrick Naulleau

Proceedings Volume 10957, 109571X (2019) https://doi.org/10.1117/12.2516384

KEYWORDS: Wavefronts, Diffraction gratings, Interferometry, Shearing interferometers, Optical alignment, Diffraction, Optical design, Sensors, Multiplexing, Monochromatic aberrations

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Proceedings Article | 17 April 2014 Paper

Paper

Actinic mask imaging: recent results and future directions from the SHARP EUV microscope

Kenneth Goldberg, Markus Benk, Antoine Wojdyla, Iacopo Mochi, Senajith Rekawa, Arnaud Allezy, Michael Dickinson, Carl Cork, Weilun Chao, Daniel Zehm, James Macdougall, Patrick Naulleau, Anne Rudack

Proceedings Volume 9048, 90480Y (2014) https://doi.org/10.1117/12.2048364

KEYWORDS: Photomasks, Extreme ultraviolet, Microscopes, Lithographic illumination, Mirrors, Fiber optic illuminators, Coherence (optics), Lenses, Extreme ultraviolet lithography, Lithography

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Proceedings Article | 20 September 2013 Paper

Paper

The SEMATECH high-NA actinic reticle review project (SHARP) EUV mask-imaging microscope

Kenneth Goldberg, Iacopo Mochi, Markus Benk, Chihcheng Lin, Arnaud Allezy, Michael Dickinson, Carl Cork, James Macdougall, Erik Anderson, Weilun Chao, Farhad Salmassi, Eric Gullikson, Daniel Zehm, Vamsi Vytla, William Cork, Jason DePonte, Gino Picchi, Ahmet Pekedis, Takeshi Katayanagi, Michael Jones, Elizabeth Martin, Patrick Naulleau, Senajith Rekawa

Proceedings Volume 8880, 88800T (2013) https://doi.org/10.1117/12.2026496

KEYWORDS: Photomasks, Extreme ultraviolet, Microscopes, Coherence (optics), Reticles, Mirrors, Lithographic illumination, Coherence imaging, Optical proximity correction, Diffraction

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Proceedings Article | 1 April 2013 Paper

Paper

Commissioning an EUV mask microscope for lithography generations reaching 8 nm

Kenneth Goldberg, Iacopo Mochi, Markus Benk, Arnaud Allezy, Michael Dickinson, Carl Cork, Daniel Zehm, James Macdougall, Erik Anderson, Farhad Salmassi, Weilun Chao, Vamsi Vytla, Eric Gullikson, Jason DePonte, M. S. Gideon Jones, Douglas Van Camp, Jeffrey Gamsby, William Ghiorso, Hanjing Huang, William Cork, Elizabeth Martin, Eric Van Every, Eric Acome, Veljko Milanovic, Rene Delano, Patrick Naulleau, Senajith Rekawa

Proceedings Volume 8679, 867919 (2013) https://doi.org/10.1117/12.2011688

KEYWORDS: Photomasks, Mirrors, Microscopes, Extreme ultraviolet, Fiber optic illuminators, Lenses, Reflectivity, Charge-coupled devices, Coating, Extreme ultraviolet lithography

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SPIE Journal Paper | 14 March 2013 Open Access

Open Access

Methodology for optimal in situ alignment and setting of bendable optics for nearly diffraction-limited focusing of soft x-rays

Daniel Merthe, Valeriy Yashchuk, Kenneth Goldberg, Martin Kunz, Nobumichi Tamura, Wayne McKinney, Nikolay Artemiev, Richard Celestre, Gregory Morrison, Erik Anderson, Brian Smith, Edward Domning, Senajith Rekawa, Howard Padmore

OE, Vol. 52, Issue 03, 033603, (March 2013) https://doi.org/10.1117/12.10.1117/1.OE.52.3.033603

KEYWORDS: Mirrors, Wavefronts, X-rays, Optical alignment, In situ metrology, X-ray optics, Optical testing, Charge-coupled devices, X-ray diffraction, Shearing interferometers

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Proceedings Article | 15 October 2012 Paper

Paper

Methodology for optimal in situ alignment and setting of bendable optics for diffraction-limited focusing of soft x-rays

Daniel Merthe, Valeriy Yashchuk, Kenneth Goldberg, Martin Kunz, Nobumichi Tamura, Wayne McKinney, Nikolay Artemiev, Richard Celestre, Gregory Morrison, Erik Anderson, Brian Smith, Edward Domning, Senajith Rekawa, Howard Padmore

Proceedings Volume 8501, 850108 (2012) https://doi.org/10.1117/12.930023

KEYWORDS: Mirrors, Wavefronts, X-rays, In situ metrology, Optical alignment, X-ray optics, Optical testing, Shearing interferometers, Metrology, Charge-coupled devices

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Proceedings Article | 23 March 2012 Paper

Paper

The SEMATECH Berkeley MET: demonstration of 15-nm half-pitch in chemically amplified EUV resist and sensitivity of EUV resists at 6.x-nm

Chris Anderson, Dominic Ashworth, Lorie Mae Baclea-An, Suchit Bhattari, Rikos Chao, Rene Claus, Paul Denham, Ken Goldberg, Andrew Grenville, Gideon Jones, Ryan Miyakawa, Ken Murayama, Hiroki Nakagawa, Senajith Rekawa, Jason Stowers, Patrick Naulleau

Proceedings Volume 8322, 832212 (2012) https://doi.org/10.1117/12.917386

KEYWORDS: Chemically amplified resists, Extreme ultraviolet, Mass attenuation coefficient, Optical lithography, Chemical elements, Extreme ultraviolet lithography, Phase shifts, Photomasks, Printing, Reticles

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Proceedings Article | 16 April 2011 Paper

Paper

Critical challenges for EUV resist materials

Patrick Naulleau, Christopher Anderson, Lorie-Mae Baclea-an, Paul Denham, Simi George, Kenneth Goldberg, Gideon Jones, Brittany McClinton, Ryan Miyakawa, Seno Rekawa, Nate Smith

Proceedings Volume 7972, 797202 (2011) https://doi.org/10.1117/12.882955

KEYWORDS: Line edge roughness, Extreme ultraviolet, Chemically amplified resists, Extreme ultraviolet lithography, Photons, Printing, Synchrotrons, Imaging spectroscopy, Stochastic processes, Light sources

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Proceedings Article | 6 April 2011 Paper

Paper

An EUV Fresnel zoneplate mask-imaging microscope for lithography generations reaching 8 nm

Kenneth Goldberg, Iacopo Mochi, Senajith Rekawa, Nathan Smith, James Macdougall, Patrick Naulleau

Proceedings Volume 7969, 796910 (2011) https://doi.org/10.1117/12.881651

KEYWORDS: Mirrors, Extreme ultraviolet, Fiber optic illuminators, Microscopes, Lenses, Photomasks, Objectives, Charge-coupled devices, Extreme ultraviolet lithography, CCD cameras

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Proceedings Article | 2 April 2011 Paper

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 | 23 March 2010 Paper

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

Paper

Assessing out-of-band flare effects at the wafer level for EUV lithography

Simi George, Patrick Naulleau, Charles Kemp, Paul Denham, Senajith Rekawa

Proceedings Volume 7636, 763626 (2010) https://doi.org/10.1117/12.847953

KEYWORDS: Extreme ultraviolet, Mirrors, Line edge roughness, Extreme ultraviolet lithography, Optical lithography, Photomasks, Semiconducting wafers, Deep ultraviolet, Reflectivity, Ruthenium

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Proceedings Article | 23 March 2010 Paper

Paper

Removal of surface contamination from EUV mirrors using low-power downstream plasma cleaning

Christopher Morgan, Patrick Naulleau, Senajith Rekawa, Paul Denham, Brian Hoef, Michael Jones, Ronald Vane

Proceedings Volume 7636, 76361Q (2010) https://doi.org/10.1117/12.846386

KEYWORDS: Plasma, Oxygen, Contamination, Mirrors, EUV optics, Extreme ultraviolet, Reflectivity, Carbon, Oxides, Extreme ultraviolet lithography

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SPIE Journal Paper | 1 October 2009

Estimating the out-of-band radiation flare levels for extreme ultraviolet lithography

Simi George, Patrick Naulleau, Senajith Rekawa, Eric Gullikson, Charles Kemp

JM3, Vol. 8, Issue 04, 041502, (October 2009) https://doi.org/10.1117/12.10.1117/1.3238514

KEYWORDS: Mirrors, Extreme ultraviolet, Reflectivity, Extreme ultraviolet lithography, Semiconducting wafers, Deep ultraviolet, Plasma, Data modeling, Ultraviolet radiation, Photomasks

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Proceedings Article | 18 March 2009 Paper

Paper

Out-of-band exposure characterization with the SEMATECH Berkeley 0.3-NA microfield exposure tool

Simi George, Patrick Naulleau, Senajith Rekawa, Eric Gullikson, Charles Drew Kemp

Proceedings Volume 7271, 72710X (2009) https://doi.org/10.1117/12.814429

KEYWORDS: Mirrors, Extreme ultraviolet, Reflectivity, Semiconducting wafers, Extreme ultraviolet lithography, Deep ultraviolet, Plasma, Data modeling, Photomasks, Imaging systems

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Proceedings Article | 21 March 2008 Paper

Paper

EUV mask reflectivity measurements with micron-scale spatial resolution

Kenneth Goldberg, Senajith Rekawa, Charles Kemp, Anton Barty, Erik Anderson, Patrick Kearney, Hakseung Han

Proceedings Volume 6921, 69213U (2008) https://doi.org/10.1117/12.772971

KEYWORDS: Reflectivity, Inspection, Photomasks, Extreme ultraviolet, Scanning electron microscopy, Signal detection, Signal to noise ratio, Contamination, Optical filters, Extreme ultraviolet lithography

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Proceedings Article | 30 October 2007 Paper

Paper

Performance of actinic EUVL mask imaging using a zoneplate microscope

Kenneth Goldberg, Patrick Naulleau, Anton Barty, Senajith Rekawa, Charles Kemp, Robert Gunion, Farhad Salmassi, Eric Gullikson, Erik Anderson, Hak-Seung Han

Proceedings Volume 6730, 67305E (2007) https://doi.org/10.1117/12.746756

KEYWORDS: Photomasks, Monochromatic aberrations, Semiconducting wafers, Extreme ultraviolet, Contrast transfer function, Extreme ultraviolet lithography, Inspection, Reflectivity, Microscopes, Charge-coupled devices

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Proceedings Article | 20 October 2006 Paper

Paper

Multilayer defects nucleated by substrate pits: a comparison of actinic inspection and non-actinic inspection techniques

A. Barty, K. Goldberg, P. Kearney, S. Rekawa, B. LaFontaine, O. Wood, J. Taylor, H.-S. Han

Proceedings Volume 6349, 63492M (2006) https://doi.org/10.1117/12.686742

KEYWORDS: Inspection, Photomasks, Extreme ultraviolet, Reflectivity, Multilayers, Signal detection, Imaging systems, Coating, Defect detection, Printing

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Proceedings Article | 17 September 2005 Paper

Paper

X-ray beam metrology and X-ray optic alignment by Hartmann wavefront sensing

Pascal Mercere, Samuel Bucourt, Gilles Cauchon, Denis Douillet, Guillaume Dovillaire, Kenneth Goldberg, Mourad Idir, Xavier Levecq, Thierry Moreno, Patrick Naulleau, Senajith Rekawa, Philippe Zeitoun

Proceedings Volume 5921, 592109 (2005) https://doi.org/10.1117/12.622799

KEYWORDS: Extreme ultraviolet, Sensors, Imaging systems, Mirrors, X-rays, Hard x-rays, X-ray optics, Calibration, Active optics, Wavefront sensors

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Proceedings Article | 8 September 2005 Paper

Paper

Ultra-high-accuracy optical testing: creating diffraction-limited short-wavelength optical systems

Kenneth Goldberg, Patrick Naulleau, Senajith Rekawa, Paul Denham, J. Liddle, Eric Gullikson, Keith Jackson, Erik Anderson, John Taylor, Gary Sommargren, Henry Chapman, Donald Phillion, Michael Johnson, Anton Barty, Regina Soufli, Eberhard Spiller, Christopher Walton, Sasa Bajt

Proceedings Volume 5900, 59000G (2005) https://doi.org/10.1117/12.618066

KEYWORDS: Extreme ultraviolet, Optical testing, Interferometry, EUV optics, X-ray optics, X-rays, Lenses, Light sources, Astronomical imaging, X-ray astronomy

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Proceedings Article | 6 May 2005 Paper

Paper

EUV microexposures at the ALS using the 0.3-NA MET projection optics

Patrick Naulleau, Kenneth Goldberg, Erik Anderson, Jason Cain, Paul Denham, Brian Hoef, Keith Jackson, Anne-Sophie Morlens, Seno Rekawa, Kim Dean

Proceedings Volume 5751, (2005) https://doi.org/10.1117/12.600388

KEYWORDS: Printing, Fiber optic illuminators, Line edge roughness, Extreme ultraviolet, Semiconducting wafers, Photomasks, Extreme ultraviolet lithography, Reticles, Projection systems, Wafer-level optics

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SPIE Journal Paper | 1 January 2005

Design and implementation of a vacuum-compatible laser-based subnanometer-resolution absolute distance measurement system

Patrick Naulleau, Paul Denham, Senajith Rekawa

OE, Vol. 44, Issue 01, 013605, (January 2005) https://doi.org/10.1117/12.10.1117/1.1830043

KEYWORDS: Sensors, Diodes, Semiconducting wafers, Distance measurement, Image segmentation, Lithography, Computer aided design, Line edge roughness, Optical engineering, Interferometry

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Proceedings Article | 20 May 2004 Paper

Paper

EUV interferometric testing and alignment of the 0.3-NA MET optic

Kenneth Goldberg, Patrick Naulleau, Paul Denham, Senajith Rekawa, Keith Jackson, James Liddle, Erik Anderson

Proceedings Volume 5374, (2004) https://doi.org/10.1117/12.546199

KEYWORDS: Monochromatic aberrations, Extreme ultraviolet, Wavefronts, Interferometry, Optical alignment, Imaging systems, Interferometers, Mirrors, Photovoltaics, EUV optics

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Proceedings Article | 20 May 2004 Paper

Paper

Status of EUV micro-exposure capabilities at the ALS using the 0.3-NA MET optic

Patrick Naulleau, Kenneth Goldberg, Erik Anderson, Kevin Bradley, Rene Delano, Paul Denham, Bob Gunion, Bruce Harteneck, Brian Hoef, Hanjing Huang, Keith Jackson, Gideon Jones, Drew Kemp, James Liddle, Ron Oort, Al Rawlins, Senajith Rekawa, Farhad Salmassi, Ron Tackaberry, Carl Chung, Layton Hale, Don Phillion, Gary Sommargren, John Taylor

Proceedings Volume 5374, (2004) https://doi.org/10.1117/12.556538

KEYWORDS: Reticles, Semiconducting wafers, Sensors, Fiber optic illuminators, Printing, Extreme ultraviolet lithography, Metrology, Wafer-level optics, Scanners, Lithography

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Proceedings Article | 16 June 2003 Paper

Paper

EUV interferometry of the 0.3-NA MET optic

Kenneth Goldberg, Patrick Naulleau, Paul Denham, Senajith Rekawa, Keith Jackson, Erik Anderson, J. Liddle, Jeffrey Bokor

Proceedings Volume 5037, (2003) https://doi.org/10.1117/12.484735

KEYWORDS: Extreme ultraviolet, Interferometry, Interferometers, EUV optics, Photomasks, Optical alignment, Optical testing, Wavefronts, Sensors, Diffraction

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Proceedings Article | 1 July 2002 Paper

Paper

Static microfield printing at the advanced light source with the ETS Set-2 optic

Patrick Naulleau, Kenneth Goldberg, Erik Anderson, David Attwood, Phillip Batson, Jeffrey Bokor, Paul Denham, Eric Gullikson, Bruce Harteneck, Brian Hoef, Keith Jackson, Deirdre Olynick, Senajith Rekawa, Farhad Salmassi, Kenneth Blaedel, Henry Chapman, Layton Hale, Regina Soufli, Eberhard Spiller, Donald Sweeney, John Taylor, Christopher Walton, Avijit Ray-Chaudhuri, Donna O'Connell, Richard Stulen, Daniel Tichenor, Charles Gwyn, Pei-yang Yan, Guojing Zhang

Proceedings Volume 4688, (2002) https://doi.org/10.1117/12.472318

KEYWORDS: Printing, Extreme ultraviolet, Lithography, Fiber optic illuminators, Interferometry, Mirrors, Reticles, Modulation transfer functions, Wavefronts, Critical dimension metrology

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Proceedings Article | 20 August 2001 Paper

Paper

Adding static printing capabilities to the EUV phase-shifting point diffraction interferometer

Patrick Naulleau, Kenneth Goldberg, Erik Anderson, Phillip Batson, Paul Denham, Keith Jackson, Senajith Rekawa, Jeffrey Bokor

Proceedings Volume 4343, (2001) https://doi.org/10.1117/12.436633

KEYWORDS: Extreme ultraviolet, Printing, Diffusers, Fiber optic illuminators, Interferometry, Mirrors, Reticles, Projection systems, Phase shifts, Lithography

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Proceedings Article | 21 July 2000 Paper

Paper

Actinic defect counting statistics over 1-cm2 area of EUVL mask blank

Seongtae Jeong, Chih-wei Lai, Senajith Rekawa, Christopher Walton, Jeffrey Bokor

Proceedings Volume 3997, (2000) https://doi.org/10.1117/12.390080

KEYWORDS: Inspection, Extreme ultraviolet, Photons, Photomasks, Extreme ultraviolet lithography, Interference (communication), Mirrors, Defect inspection, Scattering, Particles

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Proceedings Article | 30 December 1999 Paper

Paper

Cross-correlation between actinic and visible defect inspection tool for extreme ultraviolet lithography

Seongtae Jeong, Chih-wei Lai, Senajith Rekawa, Christopher Walton, Shon Prisbrey, Jeffrey Bokor

Proceedings Volume 3873, (1999) https://doi.org/10.1117/12.373375

KEYWORDS: Extreme ultraviolet lithography, Extreme ultraviolet, Inspection, Scattering, Photomasks, Sensors, Scanners, Signal detection, Defect inspection, Multilayers

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Proceedings Article | 25 June 1999 Paper

Paper

Actinic EUVL mask blank defect inspection system

Seongtae Jeong, Lewis Johnson, Yun Lin, Senajith Rekawa, Pei-yang Yan, Patrick Kearney, Edita Tejnil, James Underwood, Jeffrey Bokor

Proceedings Volume 3676, (1999) https://doi.org/10.1117/12.351101

KEYWORDS: Extreme ultraviolet lithography, Photomasks, Opacity, Sensors, Multilayers, Inspection, Defect detection, Signal detection, Defect inspection, Particles

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Showing 5 of 33 publications

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