Dr. Stefan Wurm Profile

Dr. Stefan Wurm

Managing Member

SPIE Involvement:

Conference Program Committee | Author

Publications (40)

Proceedings Article | 9 November 2015 Paper

Actinic review of EUV masks: status and recent results of the AIMS EUV system

Sascha Perlitz, Jan Hendrik Peters, Markus Weiss, Dirk Hellweg, Renzo Capelli, Krister Magnusson, Matt Malloy, Stefan Wurm

Proceedings Volume 9635, 96351D (2015) https://doi.org/10.1117/12.2205054

KEYWORDS: Extreme ultraviolet, Photomasks, Prototyping, Extreme ultraviolet lithography, Electromagnetic coupling, Metrology, Calibration, Scanners, Image acquisition, Image processing

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Proceedings Article | 4 September 2015 Paper

Enabling inspection solutions for future mask technologies through the development of massively parallel E-Beam inspection

Matt Malloy, Brad Thiel, Benjamin Bunday, Stefan Wurm, Vibhu Jindal, Maseeh Mukhtar, Kathy Quoi, Thomas Kemen, Dirk Zeidler, Anna Lena Eberle, Tomasz Garbowski, Gregor Dellemann, Jan Hendrik Peters

Proceedings Volume 9661, 96610O (2015) https://doi.org/10.1117/12.2196120

KEYWORDS: Inspection, Photomasks, Semiconducting wafers, Defect inspection, Extreme ultraviolet, Imaging systems, Wafer inspection, Optical inspection, Wafer-level optics, Optics manufacturing

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The new device architectures and materials being introduced for sub-10nm manufacturing, combined with the complexity of multiple patterning and the need for improved hotspot detection strategies, have pushed current wafer inspection technologies to their limits. In parallel, gaps in mask inspection capability are growing as new generations of mask technologies are developed to support these sub-10nm wafer manufacturing requirements. In particular, the challenges associated with nanoimprint and extreme ultraviolet (EUV) mask inspection require new strategies that enable fast inspection at high sensitivity. The tradeoffs between sensitivity and throughput for optical and e-beam inspection are well understood. Optical inspection offers the highest throughput and is the current workhorse of the industry for both wafer and mask inspection. E-beam inspection offers the highest sensitivity but has historically lacked the throughput required for widespread adoption in the manufacturing environment. It is unlikely that continued incremental improvements to either technology will meet tomorrow’s requirements, and therefore a new inspection technology approach is required; one that combines the high-throughput performance of optical with the high-sensitivity capabilities of e-beam inspection.

To support the industry in meeting these challenges SUNY Poly SEMATECH has evaluated disruptive technologies that can meet the requirements for high volume manufacturing (HVM), for both the wafer fab [1] and the mask shop. Highspeed massively parallel e-beam defect inspection has been identified as the leading candidate for addressing the key gaps limiting today’s patterned defect inspection techniques. As of late 2014 SUNY Poly SEMATECH completed a review, system analysis, and proof of concept evaluation of multiple e-beam technologies for defect inspection. A champion approach has been identified based on a multibeam technology from Carl Zeiss. This paper includes a discussion on the need for high-speed e-beam inspection and then provides initial imaging results from EUV masks and wafers from 61 and 91 beam demonstration systems. Progress towards high resolution and consistent intentional defect arrays (IDA) is also shown.

Proceedings Article | 19 March 2015 Paper

Massively parallel E-beam inspection: enabling next-generation patterned defect inspection for wafer and mask manufacturing

Matt Malloy, Brad Thiel, Benjamin Bunday, Stefan Wurm, Maseeh Mukhtar, Kathy Quoi, Thomas Kemen, Dirk Zeidler, Anna Lena Eberle, Tomasz Garbowski, Gregor Dellemann, Jan Hendrik Peters

Proceedings Volume 9423, 942319 (2015) https://doi.org/10.1117/12.2175535

KEYWORDS: Inspection, Defect inspection, Photomasks, Semiconducting wafers, Optical inspection, Wafer inspection, Extreme ultraviolet, Manufacturing, Prototyping, Optics manufacturing

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Proceedings Article | 17 October 2014 Paper

EUV lithography: progress, challenges, and outlook

S. Wurm

Proceedings Volume 9231, 923103 (2014) https://doi.org/10.1117/12.2076766

KEYWORDS: Extreme ultraviolet, Extreme ultraviolet lithography, Photomasks, Manufacturing, Optical lithography, Inspection, Pellicles, Logic, Double patterning technology, Lithography

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Proceedings Article | 17 April 2014 Paper

Driving the industry towards a consensus on high numerical aperture (high-NA) extreme ultraviolet (EUV)

Patrick Kearney, Obert Wood, Eric Hendrickx, Greg McIntyre, Soichi Inoue, Frank Goodwin, Stefan Wurm, Jan van Schoot, Winfried Kaiser

Proceedings Volume 9048, 90481O (2014) https://doi.org/10.1117/12.2048397

KEYWORDS: Photomasks, Extreme ultraviolet, Mirrors, Semiconducting wafers, Extreme ultraviolet lithography, Scanners, Imaging systems, 3D image processing, Reflectivity, Optical lithography

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Proceedings Article | 17 April 2014 Paper

Update on the SEMATECH 0.5 NA Extreme-Ultraviolet Lithography (EUVL) Microfield Exposure Tool (MET)

Kevin Cummings, Dominic Ashworth, Mark Bremer, Rodney Chin, Yu-Jen Fan, Luc Girard, Holger Glatzel, Michael Goldstein, Eric Gullikson, Jim Kennon, Bob Kestner, Lou Marchetti, Patrick Naulleau, Regina Soufli, Johannes Bauer, Markus Mengel, Joachim Welker, Michael Grupp, Erik Sohmen, Stefan Wurm

Proceedings Volume 9048, 90481M (2014) https://doi.org/10.1117/12.2046380

KEYWORDS: Extreme ultraviolet lithography, Extreme ultraviolet, Projection systems, Lithography, Reticles, Cameras, Artificial intelligence, Optical lithography, Wavefronts, Sensors

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Proceedings Article | 1 October 2013 Paper

Recent advances in SEMATECH's mask blank development program, the remaining technical challenges, and future outlook

Frank Goodwin, Patrick Kearney, Arun Kadaksham, Stefan Wurm

Proceedings Volume 8886, 88860C (2013) https://doi.org/10.1117/12.2039943

KEYWORDS: Photomasks, Extreme ultraviolet lithography, Extreme ultraviolet, Reflectivity, Multilayers, Ions, Optical lithography, Ion beams, Deposition processes, Coating

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The ability of optical lithography to steadily produce images at increasingly smaller dimension while maintaining pattern fidelity of devices with greater complexity has enabled the success of Moore’s Law. Although 193 nm immersion and double patterning techniques have proven successful in extending optical lithography, the strategies proposed for further extension are too costly to support device manufacturing. As a result, greater focus has been shifted to resolving the challenges hindering extreme ultraviolet lithography (EUVL) adoption as the mainstream lithography solution. While similar to conventional optical lithography, there are unique challenges to EUVL, one of which is the change from transmission masks to the reflective masks required for EUVL. The use of reflective reticles greatly increases complexity of EUV reticle structure when compared to the binary masks used with optical lithography. Maximizing the reflectance an EUV mask requires the use of a multilayer Bragg reflector deposited on a finely polished substrate with a thin absorber film on top used to define the device pattern. Although similar in form to the substrates used in optical lithography, the tolerances on figure, surface finish, and defects are significantly more stringent for EUV substrates. Control of aberrations and maintaining pattern fidelity places tight constraints on the flatness and roughness of the EUV substrate; imperfections and particles can result in printable defects. The Bragg reflector of the EUV mask consists of 40 to 50 Si/Mo bi-layers deposited using an ion beam deposition tool. This film stack must be deposited to meet the reflectivity and uniformity requirements of the exposure tool and must be completely free of defects. The absorber film is typically a tantalum-based nitride layer selected for its ability to absorb EUV radiation and maintain thermal stability. The thickness and morphology of this film must be tightly controlled to enable use as the patterning film for the device. In addition to the increase in complexity of the mask, introduction of EUVL requires infrastructure development of new substrate, mask blank, and finished reticle inspection tools and techniques for handling and storage of a mask without a pellicle. This paper will highlight recent advances in the ability to produce pilot line quality EUV mask blanks to meet the near-term requirements and review the existing technology gaps which must be closed to extend the current capability to meet HVM needs. A special focus will be put on substrate and mask blank defect densities; other process and infrastructure challenges will also be discussed.

Proceedings Article | 1 April 2013 Paper

Resist process applications to improve EUV patterning

Karen Petrillo, Kyoungyoung Cho, Alexander Friz, Cecilia Montgomery, Dominic Ashworth, Mark Neisser, Stefan Wurm, Takashi Saito, Lior Huli, Akiteru Ko, Andrew Metz

Proceedings Volume 8679, 867911 (2013) https://doi.org/10.1117/12.2011566

KEYWORDS: Etching, Line width roughness, Extreme ultraviolet, Image processing, Photoresist processing, Extreme ultraviolet lithography, Silicon, Lithography, Optical lithography, Photons

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Proceedings Article | 23 March 2012 Paper

Line width roughness control for EUV patterning

Karen Petrillo, George Huang, Dominic Ashworth, Liping Ren, K.-Y. Cho, Stefan Wurm, Shinichiro Kawakami, Lior Huli, Shannon Dunn, Akiteru Ko

Proceedings Volume 8322, 83222H (2012) https://doi.org/10.1117/12.925442

KEYWORDS: Line width roughness, Extreme ultraviolet lithography, Etching, Line edge roughness, Image processing, Extreme ultraviolet, Silicon, Optical lithography, Lithography, Scanning electron microscopy

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Proceedings Article | 7 April 2011 Paper

Line width roughness control and pattern collapse solutions for EUV patterning

Karen Petrillo, George Huang, Dominic Ashworth, Jacque Georger, Liping Ren, K. Y. Cho, Warren Montgomery, Stefan Wurm, Shinichiro Kawakami, Shannon Dunn, Akiteryu Ko

Proceedings Volume 7969, 796913 (2011) https://doi.org/10.1117/12.879513

KEYWORDS: Line width roughness, Extreme ultraviolet, Extreme ultraviolet lithography, Etching, Photoresist processing, Image processing, Semiconducting wafers, Optical lithography, Critical dimension metrology, Scanning electron microscopy

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Proceedings Article | 20 March 2010 Paper

A study of defects on EUV masks using blank inspection, patterned mask inspection, and wafer inspection

Sungmin Huh, Liping Ren, David Chan, Stefan Wurm, Kenneth Goldberg, Iacopo Mochi, Toshio Nakajima, Masahiro Kishimoto, Byungsup Ahn, Inyong Kang, Joo-on Park, Kyoungyong Cho, Sang-in Han, Thomas Laursen

Proceedings Volume 7636, 76360K (2010) https://doi.org/10.1117/12.846922

KEYWORDS: Photomasks, Wafer inspection, Inspection, Particles, Extreme ultraviolet, Semiconducting wafers, Extreme ultraviolet lithography, Defect detection, Mask making, High volume manufacturing

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Proceedings Article | 20 March 2010 Paper

EUV mask defect inspection and defect review strategies for EUV pilot line and high volume manufacturing

Y. David Chan, Abbas Rastegar, Henry Yun, E. Steve Putna, Stefan Wurm

Proceedings Volume 7636, 76361D (2010) https://doi.org/10.1117/12.847371

KEYWORDS: Inspection, Extreme ultraviolet, Photomasks, Extreme ultraviolet lithography, Defect inspection, Optical inspection, Particles, Reflectivity, Manufacturing, Deep ultraviolet

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Proceedings Article | 18 March 2010 Paper

Characterization of promising resist platforms for sub-30-nm HP manufacturability and EUV CAR extendibility study

Chawon Koh, Jacque Georger, Liping Ren, George Huang, Frank Goodwin, Stefan Wurm, Dominic Ashworth, Warren Montgomery, Bill Pierson, Joo-on Park, Patrick Naulleau

Proceedings Volume 7636, 763604 (2010) https://doi.org/10.1117/12.846629

KEYWORDS: Optical lithography, Extreme ultraviolet, Manufacturing, Line width roughness, Polymers, Etching, Extreme ultraviolet lithography, Resistance, Glasses, Photoresist processing

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Extreme ultraviolet lithography (EUVL) is the most effective way to print sub-30 nm features. We characterized EUVL readiness of the three major resist platforms for sub-30 nm half-pitch (HP) manufacturability using a full-field ASML alpha demo tool (ADT) scanner and studied the extendibility of EUV chemically amplified resist (CAR). Based on an "M-factor" analysis, which shows the maturity of EUV resist for 28 nm HP manufacturability, a polymer-bound photoacid generator (PAG) resist was 78% ready, a PHS hybrid resist was 81%, and a molecular glass EUV resist was 58%. The polymer-bound resist showed good resolution for 25 nm HP using the ASML ADT. It also demonstrated fair linewidth roughness (LWR) and a good lithographic process margin of 18% exposure latitude (EL) and 160 nm depth of field (DOF) for 28 nm HP patterning compared with the other resist platforms, but its resist collapse and etch resistance need to be improved for manufacturability. PHS hybrid resist showed a fair etch resistance and resist collapse performance compared to the other resist platforms, but LWR needs to be improved. The molecular resist needs to mature further, especially in resist collapse and iso-dense (ID) bias. When considering its many strong points and control of lower acid diffusion, the polymer-bound PAG resist appears to be the most suitable platform for manufacturability and EUV CAR extension. We therefore would like to encourage the development of next generation polymer-bound PAG resist with a higher etch resistance. A process window of 80 nm DOF was demonstrated for 26 nm HP patterning and a measurable DOF for 25 nm HP was achieved with the polymer-bound PAG resist. Resist collapse and LWR are major issues for 22 nm HP patterning in manufacturing. LWR improvements were achieved with various techniques, and resist collapse was greatly improved with a novel approach that uses a residual resist layer. 16 nm HP line/space (L/S) image modulation and 18 nm HP resolution were demonstrated with an EUV CAR, indicating that EUV CAR could be extended to sub-20 nm HP patterning.

Proceedings Article | 27 May 2009 Paper

EUV actinic defect inspection and defect printability at the sub-32-nm half-pitch

Sungmin Huh, Patrick Kearney, Stefan Wurm, Frank Goodwin, Hakseung Han, Kenneth Goldberg, Iacopo Mochi, Eric Gullikson

Proceedings Volume 7470, 74700Y (2009) https://doi.org/10.1117/12.835196

KEYWORDS: Photomasks, Inspection, Extreme ultraviolet, Defect inspection, Reticles, Extreme ultraviolet lithography, Multilayers, Deep ultraviolet, Semiconducting wafers, Critical dimension metrology

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Proceedings Article | 23 May 2009 Paper

Lithography development and research challenges for the ≤22nm half-pitch

Stefan Wurm

Proceedings Volume 7470, 747002 (2009) https://doi.org/10.1117/12.834186

KEYWORDS: Extreme ultraviolet lithography, Inspection, Extreme ultraviolet, Lithography, Manufacturing, Defect inspection, Photomasks, Semiconductors, Optical lithography, Airborne remote sensing

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Proceedings Article | 18 March 2009 Paper

Mask defect verification using actinic inspection and defect mitigation technology

Sungmin Huh, Patrick Kearney, Stefan Wurm, Frank Goodwin, Kenneth Goldberg, Iacopo Mochi, Eric Gullikson

Proceedings Volume 7271, 72713J (2009) https://doi.org/10.1117/12.814249

KEYWORDS: Photomasks, Inspection, Extreme ultraviolet, Defect inspection, Semiconducting wafers, Extreme ultraviolet lithography, Deep ultraviolet, Wafer inspection, Reticles, Defect detection

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Proceedings Article | 18 March 2009 Paper

Protection efficiency of a standard compliant EUV reticle handling solution

Long He, John Lystad, Stefan Wurm, Kevin Orvek, Jaewoong Sohn, Andy Ma, Patrick Kearney, Steve Kolbow, David Halbmaier

Proceedings Volume 7271, 72710I (2009) https://doi.org/10.1117/12.814304

KEYWORDS: Reticles, Extreme ultraviolet, Inspection, Photomasks, Particles, Extreme ultraviolet lithography, Silica, Semiconducting wafers, Standards development, Contamination

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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 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 | 2 May 2008 Paper

EUV blank inspection

J. Peters, C. Tonk, D. Spriegel, Hak-Seung Han, Wonil Cho, Stefan Wurm

Proceedings Volume 6792, 67920F (2008) https://doi.org/10.1117/12.798594

KEYWORDS: Inspection, Extreme ultraviolet, Photomasks, Printing, Defect detection, Particles, Quartz, Signal detection, Data centers, Defect inspection

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Proceedings Article | 3 April 2008 Paper

Benchmarking of commercial EUVL resists at SEMATECH

Andy Ma, Joo-on Park, Kim Dean, Stefan Wurm, Patrick Naulleau

Proceedings Volume 6921, 69213O (2008) https://doi.org/10.1117/12.775037

KEYWORDS: Line width roughness, Extreme ultraviolet lithography, Extreme ultraviolet, Printing, Scanning electron microscopy, Lithography, Real-time computing, Electroluminescence, Head-mounted displays, Photoresist processing

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Proceedings Article | 21 March 2008 Paper

Determining the critical size of EUV mask substrate defects

Hakseung Han, Wonil Cho, Kenneth Goldberg, Eric Gullikson, Chan-Uk Jeon, Stefan Wurm

Proceedings Volume 6921, 69211Y (2008) https://doi.org/10.1117/12.772590

KEYWORDS: Photomasks, Critical dimension metrology, Extreme ultraviolet lithography, Extreme ultraviolet, Semiconducting wafers, Charge-coupled devices, Inspection, Lithography, Scanners, Line width roughness

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Proceedings Article | 21 March 2008 Paper

Status of EUV reticle handling solution in meeting 32 nm HP EUV lithography

Long He, Stefan Wurm, Phil Seidel, Kevin Orvek, Ernie Betancourt, Jon Underwood

Proceedings Volume 6921, 69211Z (2008) https://doi.org/10.1117/12.773278

KEYWORDS: Reticles, Extreme ultraviolet, Photomasks, Particles, Inspection, Extreme ultraviolet lithography, Contamination, Robotics, EUV optics, Manufacturing

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Proceedings Article | 15 May 2007 Paper

EUV mask blank defect inspection strategies for 32-nm half-pitch and beyond

Stefan Wurm, Hakseung Han, Patrick Kearney, Wonil Cho, Chan-Uk Jeon, Eric Gullikson

Proceedings Volume 6607, 66073A (2007) https://doi.org/10.1117/12.729029

KEYWORDS: Inspection, Photomasks, Defect inspection, Extreme ultraviolet, Extreme ultraviolet lithography, Visible radiation, Printing, Wafer inspection, Mask making, Manufacturing

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Proceedings Article | 3 May 2007 Paper

EUV mask infrastructure challenges

Stefan Wurm, Phil Seidel, Chris Van Peski, Long He, Hakseung Han, Pat Kearney, Wonil Cho

Proceedings Volume 6533, 65330Z (2007) https://doi.org/10.1117/12.737154

KEYWORDS: Photomasks, Extreme ultraviolet, Inspection, Reticles, Defect inspection, Extreme ultraviolet lithography, Manufacturing, Semiconducting wafers, Standards development, Printing

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Proceedings Article | 23 March 2007 Paper

SEMATECH’s EUV program: a key enabler for EUVL introduction

Stefan Wurm, Chan-Uk Jeon, Michael Lercel

Proceedings Volume 6517, 651705 (2007) https://doi.org/10.1117/12.717756

KEYWORDS: Extreme ultraviolet, Extreme ultraviolet lithography, Photomasks, EUV optics, Optics manufacturing, Lithography, Reticles, Metrology, Particles, Defect inspection

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Proceedings Article | 15 March 2007 Paper

Status and path to a final EUVL reticle-handling solution

Long He, Kevin Orvek, Phil Seidel, Stefan Wurm, Jon Underwood, Ernie Betancourt

Proceedings Volume 6517, 65171O (2007) https://doi.org/10.1117/12.712872

KEYWORDS: Reticles, Photomasks, Extreme ultraviolet, Extreme ultraviolet lithography, Particles, Pellicles, Inspection, Robotics, Contamination, Standards development

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Proceedings Article | 23 March 2006 Paper

EUV testing of multilayer mirrors: critical issues

S. Hill, I. Ermanoski, S. Grantham, C. Tarrio, T. Lucatorto, T. Madey, S. Bajt, M. Chandhok, P. Yan, O. Wood, S. Wurm, N. Edwards

Proceedings Volume 6151, 61510F (2006) https://doi.org/10.1117/12.656502

KEYWORDS: Mirrors, Extreme ultraviolet, Reflectivity, Carbon monoxide, Extreme ultraviolet lithography, Molecules, EUV optics, Carbon, Reflectometry, Synchrotrons

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Proceedings Article | 16 June 2005 Paper

Overview of SEMATECH's EUVL program

Stefan Wurm

Proceedings Volume 5835, (2005) https://doi.org/10.1117/12.637331

KEYWORDS: Extreme ultraviolet, Extreme ultraviolet lithography, Inspection, Photomasks, Lithography, Ultraviolet radiation, EUV optics, Defect inspection, Reflectivity, Deposition processes

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Proceedings Article | 6 May 2005 Paper

UIUC collector erosion and optical lifetime project results: time dependent exposures

Darren Alman, Huatan Qiu, Keith Thompson, Erik Antonsen, Joshua Spencer, Matthew Hendricks, Brian Jurczyk, David Ruzic, Timothy Spila, Ginger Edwards, Stefan Wurm, Obert Wood, Robert Bristol

Proceedings Volume 5751, (2005) https://doi.org/10.1117/12.599978

KEYWORDS: Photodiodes, Mirrors, Extreme ultraviolet lithography, Extreme ultraviolet, Electrodes, Reflectivity, Atomic force microscopy, Scanning electron microscopy, Ions, Xenon

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Proceedings Article | 6 May 2005 Paper

Characterization of collector optic material samples before and after exposure in LPP and DPP EUV sources

Huatan Qiu, Darren Alman, Keith Thompson, Matthew Coventry, Joshua Spencer, Matthew Hendricks, Erik Antonsen, Brian Jurczyk, David Ruzic, Tim Spila, Ginger Edwards, Stefan Wurm, Obert Wood, Robert Bristol

Proceedings Volume 5751, (2005) https://doi.org/10.1117/12.600093

KEYWORDS: Molybdenum, Silicon, Ruthenium, Gold, Ions, Xenon, Palladium, Extreme ultraviolet lithography, Atomic force microscopy, Crystals

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The University of Illinois at Urbana-Champaign (UIUC) and several national laboratories are collaborating on an SEMATECH effort to characterize xenon plasma exposure effects on EUV condenser optics. A series of mirror samples provided by SEMATECH were exposed for 10M shots in an Xtreme Technologies XTS 13-35 commercial EUV discharge plasma source at UIUC and 5M at the high-power TRW laser plasma source at Sandia National Laboratories. Results for both pre and post-exposure material characterization are presented, for samples exposed in both facilities. Surface analysis performed by the Center for Microanalysis of Materials at UIUC investigates mirror degradation mechanisms by measuring changes in surface roughness, texture, and grain sizes as well as analysis of implantation of energetic Xe ions, Xe diffusion, and mixing of multilayers. Materials characterization on samples removed after varying exposure times in the XTS source, together with in-situ EUV reflectivity measurements, identify the onset of different degradation mechanisms within each sample over 1M-100M shots. Results for DPP-exposed samples for 10 million shots in our XCEED (Xtreme Commercial EUV Exposure Device) experiment showed, in general, that samples were eroded and the surfaces were roughened with little change to the texture. AFM results showed an increase in roughness by a factor of 2-5 times, with two exceptions. This was confirmed by x-ray reflectivity (XRR) data, which showed similar roughening characteristics and also confirmed the smoothening of two samples. SEM pictures showed that erosion was from 4-47 nm, depending on the sample material and angle of incidence for debris ions. Finally, microanalysis of the exposed samples indicated that electrode material was implanted at varying depths in the samples. The erosion mechanism is explored using a spherical sector energy analyzer (ESA) to measure ion species and their energy spectra. Energy spectra for ions derived from various chamber sources are measured as a function of the Argon flow rate and angle from the centerline of the pinch. Results show creation of high energy ions (up to E = 13 keV). Species noted include ions of Xe, the buffer gas, and various electrode materials. The bulk of fast ion ejection from the pinch includes Xe⁺ which maximizes at ~8 keV followed by Xe²⁺ which maximizes at ~5 keV. Data from samples analysis and ESA measurements combined indicate mechanism and effect for debris-optic interactions and detail the effectiveness of the current debris mitigation schemes.

Proceedings Article | 6 May 2005 Paper

XCEED: XTREME commercial EUV exposure diagnostic experiment

Erik Antonsen, Keith Thompson, Matthew Hendricks, Darren Alman, Brian Jurczyk, David Ruzic, Tran Duc Chinh, Ginger Edwards, Stefan Wurm, Obert Wood, Robert Bristol

Proceedings Volume 5751, (2005) https://doi.org/10.1117/12.599799

KEYWORDS: Ions, Xenon, Mirrors, Extreme ultraviolet, Photodiodes, Diagnostics, Sensors, Plasma, Reflectivity, Iron

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Proceedings Article | 6 May 2005 Paper

Investigation of plasma-induced erosion of multilayer condenser optics

Richard Anderson, Dean Buchenauer, K. Williams, W. M. Clift, L. Klebanoff, N. V. Edwards, O. Wood, S. Wurm

Proceedings Volume 5751, (2005) https://doi.org/10.1117/12.599859

KEYWORDS: Ions, Xenon, Plasma, Silicon, Molybdenum, Sputter deposition, Carbon, Pulsed laser operation, Gold, Silicon carbide

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Proceedings Article | 6 May 2005 Paper

Comparison of EUV mask architectures by process window analysis

Siegfried Schwarzl, Frank-Michael Kamm, Stefan Hirscher, Klaus Lowack, Wolf-Dieter Domke, Markus Bender, Stefan Wurm, Adam Pawloski, Bruno La Fontaine, Christian Holfeld, Uwe Dersch, Florian Letzkus, Joerg Butschke

Proceedings Volume 5751, (2005) https://doi.org/10.1117/12.599343

KEYWORDS: Photomasks, Extreme ultraviolet, Semiconducting wafers, Multilayers, Printing, Scanning electron microscopy, Cadmium, Extreme ultraviolet lithography, Binary data, Imaging systems

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Proceedings Article | 6 May 2005 Paper

The effect of debris on collector optics, its mitigation and repair: next-step a gaseous Sn EUV DPP source

Brian Jurczyk, Darren Alman, Erik Antonsen, Michael Jaworski, Michael Williams, David Ruzic, Tim Spila, Ginger Edwards, Stefan Wurm, Obert Wood, Robert Bristol

Proceedings Volume 5751, (2005) https://doi.org/10.1117/12.600048

KEYWORDS: Ions, Plasma, Tin, Extreme ultraviolet, Mirrors, Gold, EUV optics, Metals, Etching, Molybdenum

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The critical issue related to advanced fuel plasma EUV sources is collector lifetime. The Illinois Debris-mitigation EUV Applications Laboratory (IDEAL) is continuing research with a dense plasma focus (DPF) light source. The IDEAL DPF electrodes have been redesigned in order to allow for advanced fuel testing, better pinch operation and increased debris generation. The DPF light source operates at negative polarity, 50 Hz, 3 kV and 7.5 Joules of energy per pulse with tetramethyltin [(CH3)4Sn] as an advanced fuel source. EUV output power is measured with filtered photodiodes and results from a gridded energy analyzer still show two primary ion components with a high-energy peak near 6keV. A Faraday-shielded immersed RF antenna provides a 2kW secondary discharge near the DPF for both pre-ionization and mitigation of the debris with a foil trap (>90%). In addition the Surface Cleaning of Optics by Plasma Exposure (SCOPE) facility has been constructed where evaporated and/or ion implanted metals can be deposited on and removed from EUV mirrors. In SCOPE metals were evaporated on to mirror samples held at various temperatures. A metal ion beam was also added to simulate the energetic erosive flux and a helicon plasma was used in situ to study plasma cleaning. Reactive ion etching of tin by chlorine and other gases has shown 500:1 selectivity factors and very high etch rates suitable to refresh an optical mirror surface within a few seconds. Mirror samples were analyzed at the Center for Microanalysis of Material where the diffusion and transport of the metals and surface roughness were studied for lifetime estimation. Lastly, the Xtreme Characterization EUV Experiment Device (XCEED) was used for characterization of the debris has been accomplished by use of an energy sector analyzer in combination with ion time-of-flight. This diagnostic has been designed to measure velocity, mass and charge states of the incoming ions and neutrals, giving discrete debris spectra while in negative polarity operation. Latest results will be presented based on this work.

Proceedings Article | 20 May 2004 Paper

Scaling studies of capping layer oxidation by water exposure with EUV radiation and electrons

W. Clift, Leonard Klebanoff, Charles Tarrio, Steven Grantham, Obert Wood, Stefan Wurm, Nora Edwards

Proceedings Volume 5374, (2004) https://doi.org/10.1117/12.537403

KEYWORDS: Electrons, Extreme ultraviolet lithography, Silicon, Oxides, Extreme ultraviolet, Oxygen, EUV optics, Mirrors, Reflectivity, Oxidation

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Proceedings Article | 16 June 2003 Paper

Lithographic characterization of improved projection optics in the EUVL engineering test stand

Donna O'Connell, Sang Hun Lee, William Ballard, Daniel Tichenor, Louis Bernardez, Steven Haney, Terry Johnson, Pamela Barr, Alvin Leung, Karen Jefferson, William Replogle, John Goldsmith, Henry Chapman, Patrick Naulleau, Stefan Wurm, Eric Panning

Proceedings Volume 5037, (2003) https://doi.org/10.1117/12.484967

KEYWORDS: Projection systems, Lithography, Monochromatic aberrations, Extreme ultraviolet lithography, Extreme ultraviolet, Semiconducting wafers, Scanning electron microscopy, Line edge roughness, Reticles, Wavefronts

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Proceedings Article | 1 July 2002 Paper

EUV photoresist performance results from the VNL and the EUV LLC

Jonathan Cobb, Paul Dentinger, Luke Hunter, Donna O'Connell, Gregg Gallatin, William Hinsberg, Frances Houle, Martha Sanchez, Wolf-Dieter Domke, Stefan Wurm, Uzodinma Okoroanyanwu, Sang Hun Lee

Proceedings Volume 4688, (2002) https://doi.org/10.1117/12.472316

KEYWORDS: Line edge roughness, Extreme ultraviolet lithography, Photoresist materials, Scanning electron microscopy, Extreme ultraviolet, Photoresist processing, Semiconducting wafers, Deep ultraviolet, Semiconductors, Photoresist developing

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Proceedings Article | 1 July 2002 Paper

Lithographic evaluation of the EUV engineering test stand

Sang Hun Lee, Daniel Tichenor, William Ballard, Luis Bernardez, John Goldsmith, Steven Haney, Karen Jefferson, Terry Johnson, Alvin Leung, Donna O'Connell, William Replogle, John Wronosky, Kenneth Blaedel, Patrick Naulleau, Kenneth Goldberg, Eric Gullikson, Henry Chapman, Stefan Wurm, Eric Panning, Pei-yang Yan, Guojing Zhang, John Bjorkholm, Glenn Kubiak, Donald Sweeney, David Attwood, Charles Gwyn

Proceedings Volume 4688, (2002) https://doi.org/10.1117/12.472300

KEYWORDS: Extreme ultraviolet, Lithography, Projection systems, Semiconducting wafers, Extreme ultraviolet lithography, Photomasks, Reticles, Printing, Point spread functions, Image resolution

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