Mr. Benjamin D. Bunday Profile

Benjamin D. Bunday

President Founder & CEO at AMAG nanometro

SPIE Involvement:

Conference Program Committee | Author

Publications (101)

Proceedings Article | 31 July 2023 Open Access

Parallel MEMS AFM for high-throughput semiconductor metrology and inspection (Erratum)

Zhenle Cao, Benjamin Bunday, David Morris, Wyatt Sullivan

Proceedings Volume 12496, 124963Q (2023) https://doi.org/10.1117/12.3005374

KEYWORDS: Metrology, Inspection, Semiconductors, Microelectromechanical systems, Atomic force microscopy, Optical lithography, Lithography, Advanced process control

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Proceedings Article | 27 April 2023 Presentation + Paper

Simulating HV-SEM imaging of HAR and buried features

Benjamin Bunday, Seul-Ki Kang, Shari Klotzkin, Douglas Patriarche, Yvette Ball, Maseeh Mukhtar, Yuichiro Yamazaki, Kotaro Maruyama

Proceedings Volume 12496, 124960W (2023) https://doi.org/10.1117/12.2661179

KEYWORDS: Signal to noise ratio, Monte Carlo methods, Scanning electron microscopy, Optical simulations, Visualization, Oxides, Copper, Metrology, Tungsten, Line scan image sensors

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Proceedings Article | 27 April 2023 Poster + Paper

Parallel MEMS AFM for high-throughput semiconductor metrology and inspection

David R. Morris, Zhenle Cao, Wyatt Sullivan, Benjamin Bunday

Proceedings Volume 12496, 1249638 (2023) https://doi.org/10.1117/12.2658485

KEYWORDS: Line edge roughness, Microelectromechanical systems, Atomic force microscopy, Metrology, Inspection, Semiconductors, Semiconducting wafers, Scanning electron microscopy, Defect detection, Scanning probe metrology, Critical dimension metrology, Advanced process control, Surface roughness

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Proceedings Article | 26 May 2022 Presentation + Paper

Simulating process subtleties in SEM imaging

Benjamin Bunday, Shari Klotzkin, Douglas Patriarche, Maseeh Mukhtar, Kotaro Maruyama, Seul-Ki Kang, Yuichiro Yamazaki

Proceedings Volume 12053, 120530A (2022) https://doi.org/10.1117/12.2615753

KEYWORDS: Scanning electron microscopy, Monte Carlo methods, Visualization, Metrology, Photoresist materials, Chemical mechanical planarization, Silicon, Optical simulations, Signal to noise ratio

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Proceedings Article | 26 May 2022 Poster + Paper

Metrology test artifact availability improvement

Benjamin Bunday

Proceedings Volume 12053, 120531C (2022) https://doi.org/10.1117/12.2615726

KEYWORDS: Metrology, Semiconducting wafers, Reticles, Lithography, Overlay metrology, Critical dimension metrology, Wafer testing, Optical proximity correction, Scanning electron microscopy

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Proceedings Article | 22 February 2021 Presentation

High volume manufacturing metrology needs at and beyond the 5 nm node

Benjamin Bunday, Ndubuisi Orji, John Allgair

Proceedings Volume 11611, 116110F (2021) https://doi.org/10.1117/12.2584555

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Proceedings Article | 22 February 2021 Presentation

See-through imaging by HV-SEM: a simulation study

Benjamin Bunday

Proceedings Volume 11611, 1161109 (2021) https://doi.org/10.1117/12.2584544

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Proceedings Article | 20 March 2020 Presentation + Paper

Noise fidelity in SEM simulation

Benjamin Bunday

Proceedings Volume 11325, 113250R (2020) https://doi.org/10.1117/12.2559631

KEYWORDS: Monte Carlo methods, Scanning electron microscopy, Image analysis, Stochastic processes, Image quality

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Proceedings Article | 26 March 2019 Paper

Influence of sidewall perturbations of CD-SEM line roughness metrology

Benjamin Bunday, Chris Mack, Sergei Borisov, Vera Sinitsina

Proceedings Volume 10959, 109591Z (2019) https://doi.org/10.1117/12.2519312

KEYWORDS: Monte Carlo methods, Metrology, Scanning electron microscopy, Diffractive optical elements, Line edge roughness, Edge roughness, Optical simulations, Image analysis, Computer simulations, Image filtering

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Proceedings Article | 22 March 2018 Presentation + Paper

7/5nm logic manufacturing capabilities and requirements of metrology

Benjamin Bunday, A. Bello, Eric Solecky, Alok Vaid

Proceedings Volume 10585, 105850I (2018) https://doi.org/10.1117/12.2296679

KEYWORDS: Metrology, Critical dimension metrology, Scanning electron microscopy, 3D metrology, Silicon, X-rays, Overlay metrology, Fin field effect transistors, Process control, Image resolution

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Proceedings Article | 19 March 2018 Presentation

CD-SEM algorithm optimization for line roughness metrology (Conference Presentation)

Chris Mack, Ben Bunday

Proceedings Volume 10585, 105850G (2018) https://doi.org/10.1117/12.2297426

KEYWORDS: Line scan image sensors, Metrology, Optimization (mathematics), Line edge roughness, Monte Carlo methods, Scanning electron microscopy, Line width roughness, Semiconducting wafers, Semiconductor manufacturing, Critical dimension scanning electron microscopy

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Proceedings Article | 28 March 2017 Presentation + Paper

In-line E-beam metrology and defect inspection: industry reflections, hybrid E-beam opportunities, recommendations and predictions

Eric Solecky, Oliver Patterson, Andrew Stamper, Allen Rasafar, Benjamin Bunday, Kevin Wu, Jason Cantone, Alok Vaid, Weihao Weng, Xintuo Dai, Ralf Buengener

Proceedings Volume 10145, 101450R (2017) https://doi.org/10.1117/12.2261524

KEYWORDS: Defect inspection, Metrology, Process control, Critical dimension metrology, Inspection, Optical lithography, Semiconducting wafers, Dimensional metrology, Overlay metrology, Manufacturing, Electron beam lithography, Image resolution, Scanning electron microscopy, Image processing

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Proceedings Article | 28 March 2017 Paper

Metrology capabilities and needs for 7nm and 5nm logic nodes

Benjamin Bunday, Alok Vaid, A. Bello, Eric Solecky, Xintuo Dai

Proceedings Volume 10145, 101450G (2017) https://doi.org/10.1117/12.2260870

KEYWORDS: Critical dimension metrology, Nanowires, Metrology, X-rays, Semiconductors, Logic, Overlay metrology, 3D metrology, Signal processing, Inspection, Signal to noise ratio, High volume manufacturing, Silicon, Scanning electron microscopy, Image resolution

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Proceedings Article | 28 March 2017 Presentation + Paper

Using the analytical linescan model for SEM metrology

Chris Mack, Benjamin Bunday

Proceedings Volume 10145, 101451R (2017) https://doi.org/10.1117/12.2258631

KEYWORDS: Line scan image sensors, Scanning electron microscopy, Metrology, Monte Carlo methods, Inspection, Process control, Optical lithography, Critical dimension metrology, Electron microscopes, Semiconducting wafers, Edge detection, Image filtering, Gaussian filters, Calibration, Line width roughness, Digital filtering

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SPIE Journal Paper | 8 February 2017 Open Access

X-ray scattering critical dimensional metrology using a compact x-ray source for next generation semiconductor devices

R. Joseph Kline, Daniel Sunday, Donald Windover, Benjamin Bunday

JM3, Vol. 16, Issue 01, 014001, (February 2017) https://doi.org/10.1117/12.10.1117/1.JMM.16.1.014001

KEYWORDS: Scattering, Laser scattering, Silicon, X-rays, Sensors, X-ray sources, Synchrotrons, Semiconductors, Dimensional metrology

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SPIE Journal Paper | 13 October 2016

Transmission electron microscope calibration methods for critical dimension standards

Ndubuisi G. Orji, Ronald Dixson, Domingo Garcia-Gutierrez, Benjamin Bunday, Michael Bishop, Michael Cresswell, Richard Allen, John A. Allgair

JM3, Vol. 15, Issue 04, 044002, (October 2016) https://doi.org/10.1117/12.10.1117/1.JMM.15.4.044002

KEYWORDS: Critical dimension metrology, Calibration, Transmission electron microscopy, Electron microscopes, Error analysis, Silicon, Line width roughness, Oxides, Statistical analysis, Standards development

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SPIE Journal Paper | 23 August 2016

Measuring multielectron beam imaging fidelity with a signal-to-noise ratio analysis

Maseeh Mukhtar, Benjamin Bunday, Kathy Quoi, Matt Malloy, Brad Thiel

JM3, Vol. 15, Issue 03, 034004, (August 2016) https://doi.org/10.1117/12.10.1117/1.JMM.15.3.034004

KEYWORDS: Signal to noise ratio, Electrons, Monte Carlo methods, Silicon, Image processing, Scanning electron microscopy, Sensors, Inspection, Defect inspection, Defect detection

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Proceedings Article | 24 March 2016 Paper

HVM metrology challenges towards the 5nm node

Benjamin Bunday

Proceedings Volume 9778, 97780E (2016) https://doi.org/10.1117/12.2218375

KEYWORDS: Nanowires, Metrology, Critical dimension metrology, Silicon, 3D metrology, Image resolution, X-rays, Scanning electron microscopy, Etching

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Proceedings Article | 18 March 2016 Paper

Probe microscopy for metrology of next generation devices

Andrew D. Humphris, Bin Zhao, David Bastard, Benjamin Bunday

Proceedings Volume 9778, 97782L (2016) https://doi.org/10.1117/12.2219035

KEYWORDS: Metrology, Microscopes, Process control, Critical dimension metrology, Atomic force microscopy, Image processing, Microscopy, Transistors, Semiconducting wafers, Atomic force microscope, Scanning electron microscopy, 3D metrology, Semiconductors, High volume manufacturing, Nondestructive evaluation

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Proceedings Article | 18 March 2016 Paper

Improvements to the analytical linescan model for SEM metrology

Chris Mack, Benjamin Bunday

Proceedings Volume 9778, 97780A (2016) https://doi.org/10.1117/12.2218443

KEYWORDS: Scanning electron microscopy, Metrology, Monte Carlo methods, Electron microscopes, Calibration, Process control, Optical lithography, Semiconducting wafers, Silicon, Finite element methods, Neodymium, Electroluminescence

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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

Maseeh Mukhtar, Kathy Quoi, Matt Malloy, Brad Thiel, Benjamin Bunday, Vibhu Jindal, Stefan Wurm, 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 | 10 April 2015 Paper

Quantitative nanomechanical measurement of electron beam surface modification

Benjamin Bunday, Aaron Cordes, Cecilia Montgomery, Jason Osborne, Sean Hand

Proceedings Volume 9424, 94242R (2015) https://doi.org/10.1117/12.2190984

KEYWORDS: Electron beams, Semiconducting wafers, Scanning electron microscopy, Metrology, Atomic force microscopy, Data modeling, Optical testing, Scanning probe microscopy, Data acquisition, Optical simulations

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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, Kathy Quoi, Maseeh Mukhtar, Stefan Wurm, 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 | 19 March 2015 Paper

Simulating massively parallel electron beam inspection for sub-20 nm defects

Benjamin Bunday, Brad Thiel, Kathy Quoi, Maseeh Mukhtar, Matt Malloy

Proceedings Volume 9424, 94240J (2015) https://doi.org/10.1117/12.2175573

KEYWORDS: Signal to noise ratio, Silicon, Image processing, Defect inspection, Sensors, Defect detection, Scanning electron microscopy, Inspection, Computer simulations, Optical simulations

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Proceedings Article | 19 March 2015 Paper

Analytical linescan model for SEM metrology

Chris Mack, Benjamin Bunday

Proceedings Volume 9424, 94240F (2015) https://doi.org/10.1117/12.2086119

KEYWORDS: Silicon, Line scan image sensors, Monte Carlo methods, Polymethylmethacrylate, Semiconducting wafers, Scanning electron microscopy, Metrology, Edge detection, Optical simulations, Backscatter

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SPIE Journal Paper | 4 November 2014

Assessment of critical dimension small-angle x-ray scattering measurement approaches for FinFET fabrication process monitoring

Charles Settens, Aaron Cordes, Benjamin Bunday, Abner Bello, Vimal Kamineni, Abhijeet Paul, Jody Fronheiser, Richard Matyi

JM3, Vol. 13, Issue 04, 041408, (November 2014) https://doi.org/10.1117/12.10.1117/1.JMM.13.4.041408

KEYWORDS: Silicon, Scattering, X-rays, Hydrogen, Critical dimension metrology, Annealing, Metrology, Scatter measurement, Double patterning technology

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Proceedings Article | 2 October 2014 Paper

Assessing the viability of multi-electron beam wafer inspection for sub-20nm defects

Matt Malloy, Brad Thiel, Michael Lercel, Benjamin Bunday

Proceedings Volume 9236, 92360E (2014) https://doi.org/10.1117/12.2069302

KEYWORDS: Signal to noise ratio, Light scattering, Inspection, Semiconducting wafers, Defect inspection, Interference (communication), Contrast transfer function, Scanning electron microscopy, Scattering, Signal detection

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Proceedings Article | 14 April 2014 Paper

Influence of metrology error in measurement of line edge roughness power spectral density

Benjamin Bunday, Chris Mack

Proceedings Volume 9050, 90500G (2014) https://doi.org/10.1117/12.2047100

KEYWORDS: Silicon, Monte Carlo methods, Electrons, Line scan image sensors, Scanning electron microscopy, Polymethylmethacrylate, Line edge roughness, Edge detection, Metrology, Semiconducting wafers

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Proceedings Article | 2 April 2014 Paper

Novel metrology methods for fast 3D characterization of directed self-assembly (DSA) patterns for high volume manufacturing

Chandra Sarma, Benjamin Bunday, Aron Cepler, Ted Dziura, JiHoon Kim, Guanyang Lin, Jian Yin

Proceedings Volume 9050, 90500O (2014) https://doi.org/10.1117/12.2046785

KEYWORDS: Semiconducting wafers, Scatterometry, Metrology, Polymethylmethacrylate, Bridges, Data modeling, Critical dimension metrology, Picosecond phenomena, Line edge roughness, Directed self assembly

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Proceedings Article | 2 April 2014 Paper

Novel three dimensional (3D) CD-SEM profile measurements

Toshihiko Hara, Takehito Arai, Soichi Shida, Masayuki Yamagata, Jun Matsumoto, Takayuki Nakamura, Wataru Ito, Benjamin Bunday, Sumito Harada, Aaron Cordes, Tsutomu Murakawa, Abraham Arceo, Makoto Yoshikawa

Proceedings Volume 9050, 90500D (2014) https://doi.org/10.1117/12.2047374

KEYWORDS: Atomic force microscopy, 3D image processing, 3D metrology, Sensors, Semiconducting wafers, Metrology, Reticles, Line edge roughness, Scanning electron microscopy

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Proceedings Article | 2 April 2014 Paper

CD-SEM metrology for sub-10nm width features

Benjamin Bunday, Aron Cepler, Abraham Arceo, Aaron Cordes

Proceedings Volume 9050, 90500T (2014) https://doi.org/10.1117/12.2047099

KEYWORDS: Metrology, Scanning electron microscopy, Silicon, Image resolution, Edge detection, Detection and tracking algorithms, Lawrencium, 3D metrology, Optical simulations, Critical dimension metrology

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Proceedings Article | 18 April 2013 Paper

Use of TSOM for sub-11nm node pattern defect detection and HAR features

Abraham Arceo, Benjamin Bunday, Ravikiran Attota

Proceedings Volume 8681, 86812G (2013) https://doi.org/10.1117/12.2013777

KEYWORDS: Metrology, Critical dimension metrology, Defect detection, Diffusion tensor imaging, Defect inspection, Silicon, Inspection, Oxides, 3D metrology, Optical microscopy

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In-line metrologies currently used in the semiconductor industry are being challenged by the aggressive pace of device scaling and the adoption of novel device architectures. In defect inspection, conventional bright field techniques will not likely be able to meet defect capture rate requirements beyond the 16 nm node. Electron beam-based inspection is able to meet resolution limits well below this node, but operates at a significantly lower throughput. It, therefore, has become necessary to explore alternative approaches with the potential to meet both resolution and throughput requirements. Critical dimension (CD) metrology, on the other hand, is less challenged by resolution than by the increasingly 3D nature of the information that needs to be collected from modern device structures. It is therefore valuable to explore metrology techniques that are sensitive to spatial variations across the entire volume of the interrogated feature. Through-focus scanning optical microscopy (TSOM) is a novel method that allows conventional optical microscopes to collect dimensional information down to the nanometer level by combining 2D optical images captured at several through-focus positions. This relatively simple technique is inexpensive and has high throughput, making it attractive for a variety of semiconductor metrology applications, such as CD, photomask, overlay, and defect metrologies. In this work, we expand on the analysis of TSOM as a potential technique for defect inspection and study its ability to characterize 3D high aspect ratio (HAR) features. For defect inspection applications, we extend the simulation space well beyond the 11 nm node, based on dense features with CDs ranging from 13 nm to 7 nm. The optical response of a variety of patterned defect modes, sizes, and heights was likewise explored under different polarization and wavelength illumination conditions. Results indicate TSOM has the ability to extract defect signal for most of the cases studied. Work on HAR features focused on exploring 3D sensitivity to features such as bottom CD, sidewall angle, and depth. HAR targets were studied using simulations down to the 11 nm node. Promising results were observed in terms of sensitivity to bottom CD, sidewall angle, and depth.

Proceedings Article | 10 April 2013 Paper

Towards development of a sidewall roughness standard

Aaron Cordes, Ben Bunday, Hugh Porter, Sean Hand, Jason Osborne

Proceedings Volume 8681, 86812J (2013) https://doi.org/10.1117/12.2012066

KEYWORDS: Standards development, Tomography, Transmission electron microscopy, Metrology, Calibration, 3D metrology, Line edge roughness, Atomic force microscopy, Data acquisition, Iridium

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Proceedings Article | 10 April 2013 Paper

In-line E-beam wafer metrology and defect inspection: the end of an era for image-based critical dimensional metrology? New life for defect inspection

Eric Solecky, Aron Cepler, Andrew Stamper, Oliver Patterson, Erin McLellan, Alok Vaid, Carsten Hartig, Benjamin Bunday, Abraham Arceo, Ralf Buengener

Proceedings Volume 8681, 86810D (2013) https://doi.org/10.1117/12.2010007

KEYWORDS: Metrology, Defect inspection, Inspection, Ion beams, Semiconducting wafers, Scanning electron microscopy, Manufacturing, Dimensional metrology, 3D metrology, Critical dimension metrology

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Metrology measurement and defect inspection steps in routes are more pervasive than many people realize and the number continues to grow. Digging deeper, it turns out that E-beam metrology and defect inspection tools typically occupy the most overall steps and therefore are extremely critical tools for semiconductor development and manufacturing. The Critical Dimension Scanning Electron Microscope (CDSEM) is an E-beam tool responsible for image-based structural metrology measurements while the E-beam review (EBR) and E-beam inspection (EBI) tools are responsible for defect inspection. The CDSEM faces significant future challenges in a world where device architectures are changing (as with the FinFET device), increasing the need for more structural measurement parameters such as sidewall angle, height and undercut, than the CDSEM can deliver. These applications are now migrating to scattering-based tools, also referred to as model- or computational-based structural metrology techniques. We explore the history of the CDSEM, the key fundamental limits (primarily resolution) of the CDSEM preventing it from capturing these applications and assess if an image-based structural metrology tool is still needed given the niche that scattering tools are filling. The answer is yes. Next we discuss whether the CDSEM will eventually meet those needs or if other alternative solutions are needed. Lastly, we discuss an industry survey on which image-based technique holds the most promise to solve these challenges. Regarding defect inspection, resolution is also a concern for the applications that need to detect extremely small defects which current optical-based Brightfield tools cannot address. While resolution is a primary concern in structural metrology, current EBI and EBR tools possess the resolution needed for defect inspection and have extendibility through at least the next advanced technology node. We also explore the niche E-beam is filling in defect inspection, evaluate the idea that a better synergistic solution exists today between the CDSEM and the EBI tools and propose a future E-beam landscape where E-beam tool variety in future fabs is significantly reduced to enhance productivity.

Proceedings Article | 10 April 2013 Paper

Critical dimension small angle X-ray scattering measurements of FinFET and 3D memory structures

Charles Settens, Benjamin Bunday, R. Joseph Kline, Daniel Sunday, Chengqing Wang, Wen-li Wu, Richard Matyi, Brad Thiel

Proceedings Volume 8681, 86810L (2013) https://doi.org/10.1117/12.2012019

KEYWORDS: Scattering, 3D metrology, Critical dimension metrology, X-rays, Etching, Silicon, Metrology, Oxides, Scatter measurement

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Proceedings Article | 10 April 2013 Paper

Photoresist shrinkage effects in 16 nm node extreme ultraviolet (EUV) photoresist targets

Cecilia Montgomery, Warren Montgomery, Aron Cepler, Benjamin Bunday

Proceedings Volume 8681, 86810J (2013) https://doi.org/10.1117/12.2012470

KEYWORDS: Photoresist materials, Extreme ultraviolet lithography, Data modeling, Metrology, Scanning electron microscopy, Semiconducting wafers, Extreme ultraviolet, Lithography, Electron beams, Systems modeling

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Photoresist shrinkage (i.e., line slimming) is an important systematic uncertainty source in critical dimension-scanning electron microscope (CD-SEM) metrology of lithographic features [1] [2] [3] [4] [5]. It influences both the precision and the accuracy of CD-SEM measurements, while locally damaging the sample. Minimization or elimination of shrinkage is desirable, yet elusive. This error source will be a factor in CD-SEM metrology on polymer materials in EUV lithography. Recent work has demonstrated improved understanding of the trends in the shrinkage response depending on electron beam and target parameters in static measurements [2] [3] [4] [5] [6]. Some research has highlighted a second mode of shrinkage that is apparent over time and progresses as a function of time between consecutive measurements, a form of “dynamic shrinkage” that appears to be activated by electron beam, in which the activated feature perpetually and logarithmically shrinks [7] [8]. Another work has demonstrated that as pitches continue to get smaller with resulting reductions in spaces between lines, charging may emerge as an additional, competing, unpredictable error source for CD-SEM metrology on dense photoresist features, an issue that is predicted to become more common as these spaces become more confined [9]. In this work, we explore the static shrinkage behaviors of various EUV photoresists into the 16 nm half-pitch node, with samples generated using the advanced EUV lithography capable of generating such tight pitches [10]. Dynamic shrinkage behavior was explored on these materials last year [15]. The static shrinkage behaviors will be validated to show compliance with the SEMATECH shrinkage model [5] [6] on small EUV resist features. Using the results of the model fits, a simulation study will predict the shrinkage trends at future nodes. Further studies will confirm whether or not charging phenomena are observable, and the beginning of a charging simulation study will be discussed.

Proceedings Article | 10 April 2013 Paper

Gaps analysis for CD metrology beyond the 22nm node

Thomas Germer, Victor Vartanian, Aaron Cordes, Aron Cepler, Charles Settens, Benjamin Bunday

Proceedings Volume 8681, 86813B (2013) https://doi.org/10.1117/12.2012472

KEYWORDS: Critical dimension metrology, Metrology, Scanning helium ion microscopy, 3D metrology, Silicon, Image resolution, Etching, Scanning electron microscopy, Oxides

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SPIE Journal Paper | 5 June 2012

Time-dependent electron-beam-induced photoresist shrinkage effects

Benjamin Bunday, Aaron Cordes, Carsten Hartig, John Allgair, Alok Vaid, Eric Solecky, Narender Rana

JM3, Vol. 11, Issue 02, 023007, (June 2012) https://doi.org/10.1117/12.10.1117/1.JMM.11.2.023007

KEYWORDS: Photoresist materials, Metrology, Critical dimension metrology, Time metrology, Semiconducting wafers, Scanning electron microscopy, Lithography, Etching, Diffractive optical elements, Optical proximity correction

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Proceedings Article | 6 April 2012 Paper

Profile variation impact on FIB cross-section metrology

Jim Nadeau, Benjamin Bunday, Aaron Cordes

Proceedings Volume 8324, 83240Y (2012) https://doi.org/10.1117/12.917321

KEYWORDS: Metrology, Atomic force microscopy, Scanning electron microscopy, Calibration, 3D metrology, Transmission electron microscopy, Nondestructive evaluation, Line edge roughness, Reticles, Optical alignment

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The focused ion beam (FIB) milling tool is an important component of reference metrology and process characterization, both as a supporting instrument for bulk sample preparation before forwarding to the transmission electron microscope (TEM) and other instruments and as an in situ measurement instrument using angled scanning electron microscopy. As features grow denser, deeper and more demanding, full-profile reference metrology is needed, and this methodology will only grow in importance. Thus, the ability to extract accurate dimensional and profile information out of the crosssectional faces produced by FIB milling is critical. For features that demonstrate perfect symmetry in the plane of the cross section, analyzing images and extracting metrology data are straightforward. However, for industrial materials, symmetry is not a safe assumption: as features shrink, the line edge and sidewall roughness increases as a percentage of the overall feature dimension. Furthermore, with the introduction of more complex architectures such as 3D memory and FinFETs, the areas of greatest interest, such as the intersections of wrap-around gates, cannot be assumed to be symmetrical in any given plane if cut placement is not precisely controlled. Therefore it is important to establish the exact location and repeatability of the cross-section plane, both in terms of coordinate placement and effective angle of the milled surface. To this end, we prepared designed-in line edge roughness samples in the Albany Nanotech facility using SEMATECH's AMAG6 metrology reticle. The samples were thoroughly characterized before being milled by a non-destructive, sidewall-scanning atomic force microscope (AFM). These samples are then milled and measured under varying process and setup parameters using a single-beam FIB with angled SEM. We established methodologies that allow precise alignment of the cut planes of slice-and-view FIB milling to 3D-AFM scan lines to compare repeated sections throughout a feature. This gives us a large amount of data to test the accuracy and repeatability of cut placement using various alignment and recipe setup schemes.

Proceedings Article | 5 April 2012 Paper

Scanning electron microscopy imaging of ultra-high aspect ratio hole features

Aron Cepler, John Villarrubia, Benjamin Bunday, Bradley Thiel

Proceedings Volume 8324, 83241N (2012) https://doi.org/10.1117/12.916552

KEYWORDS: Particles, Electrons, Signal detection, Scanning electron microscopy, Silicon, Copper, Selenium, Metrology, Interference (communication), Oxides

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Proceedings Article | 5 April 2012 Paper

Static and dynamic photoresist shrinkage effects in EUV photoresists

Aaron Cordes, Warren Montgomery, Cecilia Montgomery, Benjamin Bunday

Proceedings Volume 8324, 83241E (2012) https://doi.org/10.1117/12.916533

KEYWORDS: Photoresist materials, Semiconducting wafers, Metrology, Extreme ultraviolet lithography, Scanning electron microscopy, Time metrology, Electron beams, Lithography, Diffractive optical elements, Data modeling

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Proceedings Article | 5 April 2012 Paper

Patterned defect and CD metrology by TSOM beyond the 22-nm node

Victor Vartanian, Benjamin Bunday, Ravikiran Attota, Abraham Arceo

Proceedings Volume 8324, 83240E (2012) https://doi.org/10.1117/12.917236

KEYWORDS: Metrology, Polarization, Critical dimension metrology, Defect detection, 3D metrology, Defect inspection, Optical microscopes, 3D acquisition, Optical microscopy

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Through-focus scanning optical microscopy (TSOM) is a novel method [1-8] that allows conventional optical microscopes to collect dimensional information down to the nanometer level by combining 2D optical images captured at several through-focus positions, transforming conventional optical microscopes into truly 3D metrology tools for nanoscale to microscale dimensional analysis with nanometer scale sensitivity. Although not a resolution enhancement method, it has been shown to provide lateral and vertical measurement sensitivity of less than a nanometer [5], comparable to the dimensional measurement sensitivity of other critical dimension (CD) metrology tools. The technique is capable of measuring features far beyond the theoretical resolution limits of optical microscopy, because it can capture much richer data at many z-heights (i.e., through focus). Additionally, TSOM appears to decouple the measurement of profile dimensional changes at the nanoscale, such as small perturbations in sidewall angle and height, with little or no ambiguity, and may be able to analyze target dimensions ranging from as small as 10 nm up to many microns with similar nanometer-scale sensitivity. Furthermore, previous simulation and experimental work has shown this method to be applicable to a variety of target materials and structures, such as nanoparticles, semiconductor memory features, and buried structures under transparent films. Additionally, this relatively simple technique is inexpensive and has high throughput, making it attractive for a variety of semiconductor metrology applications, such as CD, photomask, overlay, and defect metrologies [8]. In-line defect metrology is continuously challenged by the aggressive pace of device scaling. It is expected that the conventional brightfield techniques currently used in semiconductor manufacturing will not be able to meet defect inspection requirements near the 11 nm node. Electron beam-based inspection is able to meet resolution limits well below the 11 nm node, but operates at a significantly lower throughput. It has therefore become necessary to explore alternative approaches that have the potential to meet both resolution and throughput requirements. This work will present TSOM results of simulations and supporting experiments to demonstrate the metrology application of TSOM to features at the ITRS 22 nm node [9], including measurement of linewidths down to 10 nm, showing the ability to measure changes in line height, sidewall angle, and pitch variations. By extension, these results will show the feasibility of applying TSOM to important contemporary metrology problems in measuring doublepatterned features and FinFETs. Additionally, we will theoretically explore the use of TSOM to inspect defects on gatelevel arrays with different CDs down to 15 nm. This theoretical work consisted of modeling the optical response of cross-sectional perturbations and several patterned defect types and sizes using illumination wavelengths ranging from visible to deep ultraviolet (DUV) under different illumination polarizations. The results indicate that TSOM may be able to detect small CD and profile changes in fins of FinFET structures as well as defects that currently challenge conventional brightfield optical methods. The simulation results also indicate an added advantage of the TSOM method to differentiate certain types of defects and their orientations by exhibiting different optical intensity patterns. These results will provide insight into the feasibility of TSOM for CD and yield enhancement metrology.

SPIE Journal Paper | 24 February 2012

Sidewall slope sensitivity of critical dimension atomic force microscopy

Aaron Cordes, Benjamin Bunday, Eric Cottrell

JM3, Vol. 11, Issue 1, 011011, (February 2012) https://doi.org/10.1117/12.10.1117/1.JMM.11.1.011011

KEYWORDS: Critical dimension metrology, Semiconducting wafers, Atomic force microscopy, Calibration, Scanning electron microscopy, Metrology, Manufacturing, Silicon, Photoresist materials, Standards development

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Proceedings Article | 20 September 2011 Paper

Sidewall slope sensitivity of CD-AFM

Eric Cottrell, Aaron Cordes, Benjamin Bunday

Proceedings Volume 8105, 810506 (2011) https://doi.org/10.1117/12.896344

KEYWORDS: Semiconducting wafers, Critical dimension metrology, Calibration, Atomic force microscopy, Metrology, Scanning electron microscopy, Photoresist materials, 3D metrology, 3D image processing, Imaging systems

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Proceedings Article | 20 April 2011 Paper

TSOM method for semiconductor metrology

Ronald Dixson, András Vladár, Ravikiran Attota, James Potzick, John Kramar, Erik Novak, Benjamin Bunday, Andrew Rudack

Proceedings Volume 7971, 79710T (2011) https://doi.org/10.1117/12.881620

KEYWORDS: Silicon, Overlay metrology, Scanning electron microscopy, Optical microscopes, Metrology, 3D acquisition, 3D metrology, Polarization, 3D modeling, Photomasks

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Proceedings Article | 20 April 2011 Paper

High-speed atmospheric imaging of semiconductor wafers using rapid probe microscopy

Priyanka Kohli, David Bakker, Akira Hamaguchi, Andrew D. L. Humphris, Dilip Patel, Jeff Lyons, Abraham Arceo, Benjamin D. Bunday

Proceedings Volume 7971, 797119 (2011) https://doi.org/10.1117/12.879456

KEYWORDS: Semiconducting wafers, Image processing, Copper, Microscopy, Scanning electron microscopy, Safety, Semiconductors, Chemical mechanical planarization, Etching, Neodymium

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Proceedings Article | 20 April 2011 Paper

Scatterometry for EUV lithography at the 22-nm node

Xiaoping Liu, Warren Montgomery, Victor Vartanian, Alex Elia, Liping Ren, Benjamin Bunday, George Huang, Cecilia Montgomery

Proceedings Volume 7971, 797120 (2011) https://doi.org/10.1117/12.881407

KEYWORDS: Metrology, Extreme ultraviolet lithography, Semiconducting wafers, Critical dimension metrology, Extreme ultraviolet, Photoresist materials, Scatterometry, Lithography, Ultraviolet radiation, Process control

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Proceedings Article | 20 April 2011 Paper

Tool-to-tool matching issues due to photoresist shrinkage effects

Aaron Cordes, Narender Rana, Benjamin Bunday, Carsten Hartig, Alok Vaid, Eric Solecky, John Allgair

Proceedings Volume 7971, 79710B (2011) https://doi.org/10.1117/12.881400

KEYWORDS: Photoresist materials, Metrology, Semiconducting wafers, Lithography, Critical dimension metrology, Time metrology, Etching, Optical proximity correction, Manufacturing, Polymers

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Proceedings Article | 20 April 2011 Paper

Experimental validation of 2D profile photoresist shrinkage model

Andy Self, Lorena Ferry, Alex Danilevsky, Aaron Cordes, Benjamin Bunday

Proceedings Volume 7971, 79710W (2011) https://doi.org/10.1117/12.881406

KEYWORDS: Photoresist materials, Data modeling, Scattering, Monte Carlo methods, Lithography, Line scan image sensors, Critical dimension metrology, Metrology, Statistical modeling, Scanning electron microscopy

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For many years, lithographic resolution has been the main obstacle in allowing the pace of transistor densification to meet Moore's Law. For the 32 nm node and beyond, new lithography techniques will be used, including immersion ArF (iArF) lithography and extreme ultraviolet lithography (EUVL). As in the past, these techniques will use new types of photoresists with the capability to print smaller feature widths and pitches. These smaller feature sizes will also require the use of thinner layers of photoresists, such as under 100 nm. In previous papers, we focused on ArF and iArF photoresist shrinkage. We evaluated the magnitude of shrinkage for both R&D and mature resists as a function of chemical formulation, lithographic sensitivity, scanning electron microscope (SEM) beam condition, and feature size. Shrinkage results were determined by the well accepted methodology described in SEMATECH's CD-SEM Unified Specification. In other associated works, we first developed a 1-D model for resist shrinkage for the bottom linewidth and then a 2-D profile model that accounted for shrinkage of all aspects of a trapezoidal profile along a given linescan. A fundamental understanding of the phenomenology of the shrinkage trends was achieved, including how the shrinkage behaves differently for different sized and shaped features. In the 1-D case, calibration of the parameters to describe the photoresist material and the electron beam was all that was required to fit the models to real shrinkage data, as long as the photoresist was thick enough that the beam could not penetrate the entire layer of resist. The later 2-D model included improvements for solving the CD shrinkage in thin photoresists, which is now of great interest for upcoming realistic lithographic processing to explore the change in resist profile with electron dose and to predict the influence of initial resist profile on shrinkage characteristics. The 2-D model also included shrinkage due to both the primary electron beam directly impacting the profile and backscattered electrons from the electron beam impacting the surrounding substrate. This dose from backscattering was shown to be an important component in the resist shrinkage process, such that at lower beam energies, it dominates linewidth shrinkage. In this work, results from a previous paper will be further explored with numerically simulated results and compared to experimental results to validate the model. With these findings, we can demonstrate the state of readiness of these models for predicting the shrinkage characteristics of photoresist measurements and estimating the errors in calculating the original CD from the shrinkage trend.

SPIE Journal Paper | 1 January 2011

Measurement traceability and quality assurance in a nanomanufacturing environment

Ndubuisi Orji, Ronald Dixson, Aaron Cordes, Benjamin Bunday, John Allgair

JM3, Vol. 10, Issue 1, 013006, (January 2011) https://doi.org/10.1117/12.10.1117/1.3549736

KEYWORDS: Metrology, Calibration, Environmental sensing, Quality measurement, Manufacturing, Control systems, Data processing, Standards development, Measurement devices, Error analysis

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Proceedings Article | 24 August 2010 Paper

Multipurpose instrument calibration standard for particle beam, scanned probe and optical microscopy: NIST reference material (RM) 8820

Michael Postek, Benjamin Bunday, John Allgair, Michael Bishop, András Vladar, William Keery

Proceedings Volume 7767, 77670D (2010) https://doi.org/10.1117/12.861595

KEYWORDS: Calibration, Scanning electron microscopy, Silicon, Contamination, Standards development, Scatterometry, Metrology, Lithography, Electron microscopes, Microscopes

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Proceedings Article | 3 June 2010 Paper

NEW scanning electron microscope magnification calibration reference material (RM) 8820

John Allgair, William Keery, Michael Bishop, Michael Postek, András Vladár, Benjamin Bunday

Proceedings Volume 7729, 77290D (2010) https://doi.org/10.1117/12.859118

KEYWORDS: Calibration, Scanning electron microscopy, Electron microscopes, Silicon, Contamination, Standards development, Lithography, Electroluminescent displays, Metrology, Scatterometry

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Proceedings Article | 2 April 2010 Paper

LER detection using dark field spectroscopic reflectometry

Benjamin Bunday, Valery Sorin, Shahar Gov, Boaz Brill, Tal Marcu, Dani Hak

Proceedings Volume 7638, 76380P (2010) https://doi.org/10.1117/12.846449

KEYWORDS: Line edge roughness, Diffraction, Reflectance spectroscopy, Scattering, Rayleigh scattering, Oxides, Field spectroscopy, Reflectometry, Spectroscopy, Amplifiers

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Proceedings Article | 2 April 2010 Paper

CD-SEM utility with double patterning

Lorena Page, Shunsuke Koshihara, Yasuo Kawai, Pete Lipscomb, Benjamin Bunday, Andy Self, Yuki Ojima, Shigeki Sukegawa

Proceedings Volume 7638, 76382U (2010) https://doi.org/10.1117/12.848546

KEYWORDS: Overlay metrology, Critical dimension metrology, Double patterning technology, Semiconducting wafers, Metrology, Lithography, Etching, Optical proximity correction, Scanning electron microscopy, Pattern recognition

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Requirements for increasingly integrated metrology solutions continue to drive applications that incorporate process characterization tools, as well as the ability to improve metrology production capability and cycle time, with a single application. All of the most critical device layers today, and even non-critical layers, now require optical proximity correction (OPC), which must be rigorously modeled and calibrated as part of process development and extensively verified once new product reticles are released using critical dimension-scanning electron microscopy (CD-SEM) tools. Automatic setup of complex recipes is one of the major trends in CD-SEM applications, which is adding much value to CD-SEM metrology. In addition, as integrated circuit dimensions and pitches continue to shrink, double patterning (DP) has become more common. Thus automatic recipe setup has needed to incorporate capabilities to deal simultaneously with two layers. This has the benefit of allowing the user to measure the two different CD populations and the image shift in the lithography (i.e., the overlay). Thus automatic recipe creation can be used to characterize the DP pattern for both CD and overlay. DesignGauge, the automatic recipe utility for Hitachi CG series CD-SEMs, is not only capable of offline recipe creation, but also can also directly transfer design-based recipes into standard CD-SEM recipes for use with DP processes. These recipes can be used for OPC model-building and verification as with previous DesignGauge applications. The software also provides design template-based recipe setup for production layer recipes, which improves production tool utilization, as production recipes can thus be written offline for new products, improving first silicon cycle time, engineering time to generate recipes, and CD-SEM utilization. Another benefit of the application is that recipes are more robust than with conventional direct image-based pattern recognition. This paper explores the feasibility of matching a two-layer GDS pattern to features in an image, allowing for the more complex measurements involved in DP characterization. This work will evaluate DesignGauge with double litho double etch (DLDE DP), including rigorous tests of navigation, pattern recognition success rates, SEM image placement, throughput of the recipe creation, recipe execution, and verification of proper measurements of the dual CD populations and overlay.

Proceedings Article | 2 April 2010 Paper

Electron-beam induced photoresist shrinkage influence on 2D profiles

Benjamin Bunday, Konstantin Chirko, Vasiliki Tileli, Ram Peltinov, Mayaan Bar-Zvi, Ofer Adan, Bradley Thiel, Yohanan Avitan, John Allgair, Aaron Cordes, Daniel Bellido Aguilar

Proceedings Volume 7638, 76381L (2010) https://doi.org/10.1117/12.846991

KEYWORDS: Photoresist materials, Data modeling, Scattering, Monte Carlo methods, Lithography, Critical dimension metrology, Metrology, Laser scattering, Scanning electron microscopy, Extreme ultraviolet lithography

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For many years, lithographic resolution has been the main obstacle in keeping the pace of transistor densification to meet Moore's Law. For the 32 nm node and beyond, new lithography techniques will be used, including immersion ArF (iArF) lithography and extreme ultraviolet lithography (EUVL). As in the past, these techniques will use new types of photoresists with the capability to print smaller feature widths and pitches. Also, such smaller feature sizes will require thinner layers of photoresists, such as under 100 nm. In previous papers, we focused on ArF and iArF photoresist shrinkage. We evaluated the magnitude of shrinkage for both R&D and mature resists as a function of chemical formulation, lithographic sensitivity, scanning electron microscope (SEM) beam condition, and feature size. Shrinkage results were determined by the well accepted methodology described in ISMI's CD-SEM Unified Specification. A model for resist shrinkage, while derived elsewhere, was presented, that can be used to curve-fit to the shrinkage data resulting from multiple repeated measurements of resist features. Parameters in the curve-fit allow for metrics quantifying total shrinkage, shrinkage rate, and initial critical dimension (CD) before e-beam exposure. With these parameters and exhaustive measurements, a fundamental understanding of the phenomenology of the shrinkage trends was achieved, including how the shrinkage behaves differently for different sized features. This work was extended in yet another paper in which we presented a 1-D model for resist shrinkage that can be used to curve-fit to shrinkage curves. Calibration of parameters to describe the photoresist material and the electron beam were all that were required to fit the model to real shrinkage data, as long as the photoresist was thick enough that the beam could not penetrate the entire layer of resist. In this paper, we extend this work yet again to a 2-D model of a trapezoidal photoresist profile. This model thus allows CD shrinkage in thin photoresist to be solved, which is now of great interest for upcoming realistic lithographic processing. It also allows us to predict the change in resist profile with electron dose and the influence of initial resist profile on shrinkage characteristics. In this work, the results from the previous paper will be shown to be consistent with numerically simulated results, thus lending credibility to these papers' postulations. Also, results from this 2-D profile model can also give clues as to how we might, in the future, model the shrinkage of contour edges of 3-D shapes. With these findings, we can conclude with observations about the readiness of SEM metrology for the challenges of future photoresist measurement, as well as estimate the errors involved in calculating the original CD from the shrinkage trend.

Proceedings Article | 2 April 2010 Paper

Reference material (RM) 8820: a versatile new NIST standard for nanometrology

William Keery, Michael Postek, Michael Bishop, John Allgair, Andras Vladar, Benjamin Bunday

Proceedings Volume 7638, 76381B (2010) https://doi.org/10.1117/12.848037

KEYWORDS: Calibration, Scanning electron microscopy, Silicon, Contamination, Standards development, Metrology, Lithography, Electron microscopes, Electroluminescent displays, Scatterometry

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Proceedings Article | 21 August 2009 Paper

Measurement traceability and quality assurance in a nanomanufacturing environment

Aaron Cordes, John Allgair, N. George Orji, Benjamin Bunday, Ronald Dixson

Proceedings Volume 7405, 740505 (2009) https://doi.org/10.1117/12.826606

KEYWORDS: Metrology, Calibration, Environmental sensing, Quality measurement, Manufacturing, Control systems, Data processing, Measurement devices, Time metrology, Error analysis

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Proceedings Article | 24 March 2009 Paper

Nonplanar high-k dielectric thickness measurements using CD-SAXS

Benjamin Bunday, Yi-Ching Chen, Ronald Jones, Derek Ho, Kwang-Woo Choi, Jimmy Price, Chengqing Wang, Erik Lin, Christopher Soles, Wen-Li Wu

Proceedings Volume 7272, 72722M (2009) https://doi.org/10.1117/12.813757

KEYWORDS: Dielectrics, Scanning electron microscopy, Scattering, X-rays, Data modeling, Sensors, Transistors, Critical dimension metrology, Laser scattering, Silicon

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Proceedings Article | 24 March 2009 Paper

Phenomenology of electron-beam-induced photoresist shrinkage trends

Aaron Cordes, Maayan Bar-zvi, Ram Peltinov, John Allgair, Ofer Adan, Benjamin Bunday, Yohanan Avitan, Eric Cottrell, Sean Hand, Vasiliki Tileli

Proceedings Volume 7272, 72721B (2009) https://doi.org/10.1117/12.816249

KEYWORDS: Photoresist materials, Data modeling, Monte Carlo methods, Lithography, Metrology, Scanning electron microscopy, Critical dimension metrology, Semiconducting wafers, Roentgenium, Contamination

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For many years, lithographic resolution has been the main obstacle in keeping the pace of transistor densification to meet Moore's Law. For the 45 nm node and beyond, new lithography techniques are being considered, including immersion ArF (iArF) lithography and extreme ultraviolet lithography (EUVL). As in the past, these techniques will use new types of photoresists with the capability to print 45 nm node (and beyond) feature widths and pitches. In a previous paper [1], we focused on ArF and iArF photoresist shrinkage. We evaluated the magnitude of shrinkage for both R&D and mature resists as a function of chemical formulation, lithographic sensitivity, scanning electron microscope (SEM) beam condition, and feature size. Shrinkage results were determined by the well accepted methodology described in ISMI's CD-SEM Unified Specification [2]. A model for resist shrinkage, while derived elsewhere [3], was presented, that can be used to curve-fit to the shrinkage data resulting from multiple repeated measurements of resist features. Parameters in the curve-fit allow for metrics quantifying total shrinkage, shrinkage rate, and initial critical dimension (CD) from before e-beam exposure. The ability to know this original CD is the most desirable result; in this work, the ability to use extrapolation to solve for a given original CD value was also experimentally validated by CD-atomic force microscope (AFM) reference metrology. Historically, many different conflicting shrinkage results have been obtained among the many works generated through the litho-metrology community. This work, backed up by an exhaustive dataset, will present an explanation that makes sense of these apparent discrepancies. Past models for resist shrinkage inherently assumed that the photoresist line is wider than the region of the photoresist to be shrunk [3], or, in other words, the e-beam never penetrates enough to reach all material in the interior of a feature; consequently, not all photoresist is affected by the shrinkage process. In actuality, there are two shrinkage regimes, which are dependent on resist feature CD or thickness. Past shrinkage models are true for larger features. However, our results show that when linewidth becomes less than the eventual penetration depth of the e-beam after full shrinkage, the apparent shrinkage magnitude decreases while shrinkage speed accelerates. Thus, for small features, most shrinkage occurs within the first measurement. This is crucial when considering the small features to be fabricated by immersion lithography. In this work, the results from the previous paper [1] will be shown to be consistent with numerically simulated results, thus lending credibility to the postulations in [1]. With these findings, we can conclude with observations about the readiness of SEM metrology for the challenges of both dry and immersion ArF lithographies as well as estimate the errors involved in calculating the original CD from the shrinkage trend.

Proceedings Article | 24 March 2009 Paper

Monitoring measurement tools: new methods for driving continuous improvements in fleet measurement uncertainty

Dmitriy Shneyder, Alok Vaid, Andrew Brendler, Matthew Sendelbach, Mary Zaitz, Benjamin Bunday, Bill Banke, Mark Kelling, Ron Fiege, Eric Solecky, Chas Archie, Srinivasan Rangarajan, Carlos Strocchia-rivera, Carsten Hartig, William Muth, Andres Munoz, Jon-Tobias Hoeft, John Allgair, Bernd Schulz

Proceedings Volume 7272, 72721H (2009) https://doi.org/10.1117/12.814089

KEYWORDS: Semiconducting wafers, Metrology, Scatterometry, Process control, Calibration, Manufacturing, Overlay metrology, Time metrology, Atomic force microscopy

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Ever shrinking measurement uncertainty requirements are difficult to achieve for a typical metrology toolset, especially over the entire expected life of the fleet. Many times, acceptable performance can be demonstrated during brief evaluation periods on a tool or two in the fleet. Over time and across the rest of the fleet, the most demanding processes often have measurement uncertainty concerns that prevent optimal process control, thereby limiting premium part yield, especially on the most aggressive technology nodes. Current metrology statistical process control (SPC) monitoring techniques focus on maintaining the performance of the fleet where toolset control chart limits are derived from a stable time period. These tools are prevented from measuring product when a statistical deviation is detected. Lastly, these charts are primarily concerned with daily fluctuations and do not consider the overall measurement uncertainty. It is possible that the control charts implemented for a given toolset suggest a healthy fleet while many of these demanding processes continue to suffer measurement uncertainty issues. This is especially true when extendibility is expected in a given generation of toolset. With this said, there is a need to continually improve the measurement uncertainty of the fleet until it can no longer meet the needed requirements at which point new technology needs to be entertained. This paper explores new methods in analyzing existing SPC monitor data to assess the measurement performance of the fleet and look for opportunities to drive improvements. Long term monitor data from a fleet of overlay and scatterometry tools will be analyzed. The paper also discusses using other methods besides SPC monitors to ensure the fleet stays matched; a set of SPC monitors provides a good baseline of fleet stability but it cannot represent all measurement scenarios happening in product recipes. The analyses presented deal with measurement uncertainty on non-measurement altering metrology toolsets such as scatterometry, overlay, atomic force microscopy (AFM) or thin film tools. The challenges associated with monitoring toolsets that damage the sample such as the CD-SEMs will also be discussed. This paper also explores improving the monitoring strategy through better sampling and monitor selection. The industry also needs to converge regarding the metrics used to describe the matching component of measurement uncertainty so that a unified approach is reached regarding how to best drive the much needed improvements. In conclusion, there will be a discussion on automating these new methods3,4 so they can complement the existing methods to provide a better method and system for controlling and driving matching improvements in the fleet.

Proceedings Article | 23 March 2009 Paper

CD-SEM parameter influence on image resolution and measurement accuracy

Uwe Kramer, Benjamin Bunday

Proceedings Volume 7272, 727204 (2009) https://doi.org/10.1117/12.816251

KEYWORDS: Scanning electron microscopy, Image resolution, Semiconducting wafers, Signal to noise ratio, Calibration, MATLAB, Monochromatic aberrations, Etching, Fourier transforms, Manufacturing

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Proceedings Article | 23 March 2009 Paper

Dark-field optical scatterometry for line-width-roughness metrology

G. Vera Zhuang, Steven Spielman, Leonid Poslavsky, Benjamin Bunday, Daniel Wack, John Fielden

Proceedings Volume 7272, 72720L (2009) https://doi.org/10.1117/12.813007

KEYWORDS: Line width roughness, Critical dimension metrology, Light scattering, Line edge roughness, Scattering, Semiconducting wafers, Scanning electron microscopy, Metrology, Scatterometry, Diffraction

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Proceedings Article | 23 March 2009 Paper

Developing an uncertainty analysis for optical scatterometry

Thomas Germer, Benjamin Bunday, Heather Patrick, Richard Silver

Proceedings Volume 7272, 72720T (2009) https://doi.org/10.1117/12.814835

KEYWORDS: Scatterometry, Scatter measurement, Optical properties, Photoresist materials, Uncertainty analysis, Spectroscopy, Silicon, Oxides, Error analysis, Data modeling

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Proceedings Article | 19 March 2009 Open Access

Improving optical measurement accuracy using multi-technique nested uncertainties

A. Heckert, R. Dixson, R. Silver, N. F. Zhang, T. Germer, H. Zhou, B. Barnes, B. Bunday

Proceedings Volume 7272, 727202 (2009) https://doi.org/10.1117/12.816569

KEYWORDS: Metrology, Critical dimension metrology, Atomic force microscopy, Scatterometry, Optical testing, Scanning electron microscopy, Uncertainty analysis, Reflectivity, Microscopy, Line edge roughness

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Proceedings Article | 9 September 2008 Paper

Accuracy considerations for critical dimension semiconductor metrology

N. Orji, R. Dixson, J. Allgair, B. Bunday

Proceedings Volume 7042, 70420A (2008) https://doi.org/10.1117/12.796372

KEYWORDS: Metrology, Calibration, Transmission electron microscopy, Semiconductors, Standards development, Lithography, Atomic force microscope, Line edge roughness, Atomic force microscopy, Carbon nanotubes

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Proceedings Article | 16 April 2008 Paper

Characterization of sub-50-nm line array structures with angle-resolved multiple wavelength scatterometry

Michael Kotelyanskii, Benjamin Bunday, Fei Shen, Gary Jiang

Proceedings Volume 6922, 69223N (2008) https://doi.org/10.1117/12.772580

KEYWORDS: Semiconducting wafers, Amorphous silicon, Data modeling, Finite element methods, Scatterometry, Critical dimension metrology, Refractive index, Metrology, Precision measurement, Statistical modeling

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Proceedings Article | 16 April 2008 Paper

Impact of sampling on uncertainty: semiconductor dimensional metrology applications

Vladimir Ukraintsev, Bart Rijpers, Chas Archie, Bill Banke, Benjamin Bunday, Thomas Hingst, Masafumi Asano, Ingrid Peterson

Proceedings Volume 6922, 69220X (2008) https://doi.org/10.1117/12.772993

KEYWORDS: Critical dimension metrology, Semiconducting wafers, Metrology, Process control, Statistical analysis, Calibration, Scatterometry, Multiphoton fluorescence microscopy, Scanning electron microscopy, Etching

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Proceedings Article | 24 March 2008 Paper

Linewidth roughness and cross-sectional measurements of sub-50 nm structures with CD-SAXS and CD-SEM

Christopher Soles, Chengqing Wang, Wen-li Wu, Kwang-Woo Choi, Benjamin Bunday, Eric Lin, Ronald Jones, John Villarrubia, James Clarke

Proceedings Volume 6922, 69221Z (2008) https://doi.org/10.1117/12.773558

KEYWORDS: Line width roughness, Line edge roughness, Diffraction, X-rays, Critical dimension metrology, Scattering, Sensors, Laser scattering, Extreme ultraviolet lithography, Extreme ultraviolet

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Proceedings Article | 24 March 2008 Paper

Characterization of CD-SEM metrology for iArF photoresist materials

Benjamin Bunday, Ofer Adan, John Allgair, Dan Cochran, Bryan Rice, Jeff Byers, Ram Peltinov, Emil Piscani, Aaron Cordes, Maayan Bar-zvi, N. Orji, Yohanan Avitan

Proceedings Volume 6922, 69221A (2008) https://doi.org/10.1117/12.774317

KEYWORDS: Photoresist materials, Lithography, Metrology, Scanning electron microscopy, Semiconducting wafers, Atomic force microscopy, Roentgenium, Critical dimension metrology, Extreme ultraviolet, Cadmium

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Proceedings Article | 24 March 2008 Paper

Measurement of high-k and metal film thickness on FinFET sidewalls using scatterometry

Benjamin Bunday, Muhammad Hussain, Casey Smith, Thaddeus Dziura, Xiafang Zhang, Jimmy Price, Rusty Harris

Proceedings Volume 6922, 69220V (2008) https://doi.org/10.1117/12.773593

KEYWORDS: Semiconducting wafers, Metals, Scatterometry, Dielectrics, Tin, Metrology, Data modeling, Silicon, Oxides

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Proceedings Article | 24 March 2008 Paper

CD-SAXS measurements using laboratory-based and synchrotron-based instruments

Wei-En Fu, Kwang-Woo Choi, Ronald Jones, Chengqing Wang, Christopher Soles, James Clarke, Benjamin Bunday, Eric Lin, Wen-Li Wu, Derek Ho

Proceedings Volume 6922, 69222E (2008) https://doi.org/10.1117/12.773774

KEYWORDS: Diffraction, Line width roughness, Line edge roughness, Synchrotrons, X-rays, Satellites, Metrology, X-ray diffraction, Collimation, Scattering

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Proceedings Article | 22 March 2008 Paper

Toward accurate feature shape metrology

Benjamin Bunday, Ronald Dixson, Ndubuisi Orji, John Allgair

Proceedings Volume 6922, 692208 (2008) https://doi.org/10.1117/12.774426

KEYWORDS: Calibration, Transmission electron microscopy, Metrology, Atomic force microscope, Process control, Atomic force microscopy, Head, Electron microscopes, Binary data, Feature extraction

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Proceedings Article | 5 April 2007 Paper

Fundamental limits of optical critical dimension metrology: a simulation study

John Allgair, Bryan Barnes, Ravikiran Attota, Jay Jun, Richard Silver, Thomas Germer, Egon Marx, Benjamin Bunday

Proceedings Volume 6518, 65180U (2007) https://doi.org/10.1117/12.716604

KEYWORDS: Scatterometry, Reflectivity, Polarization, Finite-difference time-domain method, Data modeling, Diffraction, Oxides, Silicon, Critical dimension metrology, Amorphous silicon

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Proceedings Article | 5 April 2007 Paper

Major trends in extending CD-SEM utility

Kyoungmo Yang, Benjamin Bunday, Lorena Page, Shunsuke Koshihara, John Allgair, Hidetoshi Morokuma, Alex Danilevsky, Cindy Parker

Proceedings Volume 6518, 651835 (2007) https://doi.org/10.1117/12.714193

KEYWORDS: Pattern recognition, Critical dimension metrology, Metrology, Optical proximity correction, Semiconducting wafers, Reticles, Inspection, Scanning electron microscopy, Yield improvement, Detection and tracking algorithms

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Requirements for increasingly integrated metrology solutions continue to drive applications that incorporate process characterization tools, as well as the ability to improve metrology production capability and cycle time, with a single application. All of the most critical device layers today, along with even non-critical layers, now require optical proximity correction (OPC), which must be rigorously modeled and calibrated as part of process development and extensively verified once new product reticles are released using critical dimension-scanning electron microscopy (CD-SEM) tools. Automatic setup of complex recipes is one of the major trends in CD-SEM applications, which is adding much value to CD-SEM metrology. In addition, as integrated circuit dimensions continue to shrink, local line width variation influences the statistical confidence of a measured CD's representation of the process. A feature, called "Average CD (ACD)," measures multiple targets within the field of view (FOV). ACD allows not only measurements of a single data point representing one discrete feature, but also sampling of the mean and variance of the process. These two applications, automatic recipe creation and ACD, are combined in the second version of the DesignGauge software, which is available for the latest-generation Hitachi S-9380II CD-SEMs. DesignGauge V2 is not only capable of offline recipe creation and CD-SEM control, but it also has the ability to directly transfer design-based recipes into standard CD-SEM recipes. These recipes can be used for OPC model-building and verification as with previous DesignGauge applications. The software also provides design template-based recipe setup for production layer recipes, which yields much needed improvement to production tool utilization, as production recipes can thus be written offline for new products, improving first silicon cycle time, reducing engineering time required to generate recipes, and improving CD-SEM utilization. Another benefit of the application is an improvement in recipe robustness over conventional direct image-based pattern recognition. This work will show an extensive evaluation of DesignGauge V2, including rigorous tests of navigation, pattern recognition success rates, SEM image placement, throughput of recipe creation, and recipe execution. The impact of ACD will also be evaluated.

Proceedings Article | 5 April 2007 Paper

SEM metrology for advanced lithographies

Yohanan Avitan, Benjamin Bunday, Maayan Bar-zvi, Jeff Byers, Roni Shneck, John Swyers, Ofer Adan, John Allgair, Ram Peltinov, Bryan Rice

Proceedings Volume 6518, 65182B (2007) https://doi.org/10.1117/12.714203

KEYWORDS: Lithography, Photoresist materials, Metrology, Deep ultraviolet, Extreme ultraviolet lithography, Extreme ultraviolet, Scanning electron microscopy, 193nm lithography, Semiconducting wafers, Scanners

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Proceedings Article | 5 April 2007 Paper

The coming of age of tilt CD-SEM

O. Adan, M. Bar-zvi, N. Orji, E. Solecky, J. Beach, C. Archie, B. Bunday, J. Allgair, J. Swyers, R. Peltinov

Proceedings Volume 6518, 65181S (2007) https://doi.org/10.1117/12.714214

KEYWORDS: Photoresist materials, Semiconducting wafers, Metrology, Critical dimension metrology, Scanning electron microscopy, Scanners, Lithography, Process control, Calibration

Read Abstract +

The need for 3D metrology is becoming more urgent to address critical gaps in metrology for both lithographic and etch processes. Current generation lithographic processing (ArF source, where λ=193 nm) sometimes results in photoresist lines with re-entrant profiles or T-topping, as do many etch processes. A re-entrant profile misleads top-down metrology into reading the critical dimension (CD) as too large. Recent advances in gate process technology also raise challenges to traditional top-down metrology. One such example is the FinFET, which is truly a 3D device with 3D metrology needs. The ability to measure the bottom width of a profile is crucial for process control. Recently, tilt-beam critical dimension-scanning electron microscopy (CD-SEM) applications have been developed to measure the bottom CD of such features, using the tilted-view to "see" the bottom, avoiding the feature's larger top. This is an important achievement, as the bottom of a profile is the main feature of interest in many processes. Estimation of sidewall angle (SWA) is also important. For several years, tilt-beam CD-SEM has been an available technique for this measurement, with limited adoption by the litho-metrology community. However, in this paper we will explore another method to use the tilt feature to measure average sidewall angle, based on edgewidth measurement and the assumption of basic trapezoidal profile and known height and combined with the ability to sample multiple-features. While it will not provide exact profile shape, this technique can be quite useful in providing average profile information and will definitely exhibit good throughput. Samples used will be photoresist and etched FinFET structures to measure sidewall angles. Correlations of the results to a traceable CD-atomic force microscopy (AFM) reference measurement system are provided. Conclusions will show preliminary findings of the readiness of tilt-beam CD-SEM for measuring profile and, by extension, the status of measuring 3D structures such as FinFETs, and using CD-SEM as a direct control of lithographic tooling for T-topped photoresist profiles.

Proceedings Article | 5 April 2007 Paper

TEM calibration methods for critical dimension standards

Ronald Dixson, Domingo Garcia-Gutierrez, John Allgair, Ndubuisi Orji, Michael Cresswell, Michael Bishop, Benjamin Bunday, Richard Allen

Proceedings Volume 6518, 651810 (2007) https://doi.org/10.1117/12.713368

KEYWORDS: Transmission electron microscopy, Calibration, Standards development, Crystals, Electron microscopes, Scanning electron microscopy, Metrology, Silicon, Atomic force microscope, Image resolution

Read Abstract +

One of the key challenges in critical dimension (CD) metrology is finding suitable calibration standards. Over the last few years there has been some interest in using features measured with the transmission electron microscope (TEM) as primary standards for linewidth measurements. This is because some modes of TEM can produce lattice-resolved images having scale traceability to the SI (Systeme International d'Unites or International System of Units) definition of length through an atomic lattice constant. As interest in using calibration samples that are closer to the length scales being measured increases, so will the use of these TEM techniques. An area where lattice-traceable images produced by TEM has been used as a primary standard is in critical dimension atomic force microscope (CD-AFM) tip width calibration. Two modes of TEM that produce crystal lattice-traceable images are high resolution transmission electron microscope (HR-TEM) and high angle annular dark field scanning transmission electron microscope (HAADF-STEM). HR-TEM produces lattice-traceable images by interference patterns of the diffracted and transmitted beams rather than the actual atomic columns, while HAADF-STEM produces direct images of the crystal lattice. The difference in how both of these techniques work could cause subtle variations in the way feature edges are defined. In this paper, we present results from width samples measured using HR-TEM and HAADF-STEM. Next we compare the results with measurements taken from the same location by two different CD-AFMs. Both of the CD-AFM instruments used for this work have been calibrated using a single crystal critical dimension reference material (SCCDRM). These standards, developed by the National Institute of Standards and Technology (NIST) and SEMATECH, used HR-TEM for traceable tip-width calibration. Consequently, the present work and the previous SCCDRM work provide a mutual cross-check on the traceability of the width calibration. Excellent agreement was observed.

Proceedings Article | 5 April 2007 Paper

Realizing "value-added" metrology

Iraj Emami, Vladamir Ukraintsev, Bill Banke, Chas Archie, Bryan Rice, Benjamin Bunday, Mark Caldwell, Bhanwar Singh, Eric Solecky, Jennifer Morningstar, John Allgair, Dilip Patel, Alfredo Herrera, Pete Lipscomb, Jason Cain, Jeff Ritchison, Jerry Schlessinger

Proceedings Volume 6518, 65181K (2007) https://doi.org/10.1117/12.714216

KEYWORDS: Metrology, Overlay metrology, Inspection, Semiconducting wafers, Process control, Yield improvement, Critical dimension metrology, Optical proximity correction, Etching, Lithography

Read Abstract +

The conventional premise that metrology is a "non-value-added necessary evil" is a misleading and dangerous assertion, which must be viewed as obsolete thinking. Many metrology applications are key enablers to traditionally labeled "value-added" processing steps in lithography and etch, such that they can be considered integral parts of the processes. Various key trends in modern, state-of-the-art processing such as optical proximity correction (OPC), design for manufacturability (DFM), and advanced process control (APC) are based, at their hearts, on the assumption of fine-tuned metrology, in terms of uncertainty and accuracy. These trends are vehicles where metrology thus has large opportunities to create value through the engineering of tight and targetable process distributions. Such distributions make possible predictability in speed-sorts and in other parameters, which results in high-end product. Additionally, significant reliance has also been placed on defect metrology to predict, improve, and reduce yield variability. The necessary quality metrology is strongly influenced by not only the choice of equipment, but also the quality application of these tools in a production environment. The ultimate value added by metrology is a result of quality tools run by a quality metrology team using quality practices. This paper will explore the relationships among present and future trends and challenges in metrology, including equipment, key applications, and metrology deployment in the manufacturing flow. Of key importance are metrology personnel, with their expertise, practices, and metrics in achieving and maintaining the required level of metrology performance, including where precision, matching, and accuracy fit into these considerations. The value of metrology will be demonstrated to have shifted to "key enabler of large revenues," debunking the out-of-date premise that metrology is "non-value-added." Examples used will be from critical dimension (CD) metrology, overlay, films, and defect metrology.

Proceedings Article | 5 April 2007 Paper

Line edge roughness characterization of sub-50nm structures using CD-SAXS: round-robin benchmark results

James Clarke, Ronald Jones, Bryan Rice, Eric Lin, Robert Bristol, John Villarrubia, Kwang-Woo Choi, Chengqing Wang, Benjamin Bunday, Michael Leeson, Jeanette Roberts, Wen-li Wu

Proceedings Volume 6518, 65181O (2007) https://doi.org/10.1117/12.725380

KEYWORDS: Line width roughness, Line edge roughness, Diffraction, Critical dimension metrology, Photoresist materials, X-rays, Scattering, Satellites, Extreme ultraviolet lithography, Sensors

Read Abstract +

SPIE Journal Paper | 1 April 2007

Progress on implementation of a reference measurement system based on a critical-dimension atomic force microscope

Ndubuisi Orji, Ronald Dixson, Angela Martinez, Benjamin Bunday, John Allgair, Theodore Vorburger

JM3, Vol. 6, Issue 02, 023002, (April 2007) https://doi.org/10.1117/12.10.1117/1.2728742

KEYWORDS: Calibration, Standards development, Error analysis, Scanners, Atomic force microscope, Silicon, Semiconductor manufacturing, Semiconductors, Metrology, Semiconducting wafers

Read Abstract +

Proceedings Article | 24 March 2006 Paper

Calibrating optical overlay measurements

M. Stocker, W. Lipscomb, M. Bishop, B. Bunday, R. Attota, R. Silver, J. Allgair

Proceedings Volume 6152, 615211 (2006) https://doi.org/10.1117/12.659597

KEYWORDS: Overlay metrology, Scanning electron microscopy, Atomic force microscopy, Calibration, Metrology, Interfaces, Semiconducting wafers, Line edge roughness, Optical testing, Wafer-level optics

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Proceedings Article | 24 March 2006 Paper

Litho-metrology challenges for the 45-nm technology node and beyond

Pete Lipscomb, Ndubuisi Orji, John Allgair, Benjamin Bunday, Mike Bishop

Proceedings Volume 6152, 61520C (2006) https://doi.org/10.1117/12.659059

KEYWORDS: Overlay metrology, Metrology, Critical dimension metrology, Scanning electron microscopy, Semiconducting wafers, Amorphous silicon, Reticles, Calibration, Manufacturing, Lithography

Read Abstract +

Proceedings Article | 24 March 2006 Paper

Small feature accuracy challenge for CD-SEM metrology: physical model solution

Aviram Tam, Sergey Latinski, Guy Eytan, John Allgair, Ofer Adan, Benjamin Bunday

Proceedings Volume 6152, 61520S (2006) https://doi.org/10.1117/12.659779

KEYWORDS: Scanning electron microscopy, Metrology, Cadmium, 3D modeling, Stereoscopy, Critical dimension metrology, Transmission electron microscopy, Silicon, Algorithm development, Calibration

Read Abstract +

Proceedings Article | 24 March 2006 Paper

Automated CD-SEM recipe creation: a new paradigm in CD-SEM utilization

Kyoungmo Yang, John Allgair, Alex Danilevsky, Shunsuke Koshihara, Lorena Page, Hidetoshi Morokuma, Benjamin Bunday, William Lipscomb

Proceedings Volume 6152, 61521B (2006) https://doi.org/10.1117/12.659759

KEYWORDS: Pattern recognition, Semiconducting wafers, Optical proximity correction, Scanning electron microscopy, Computer aided design, Lithography, Metrology, Scatterometry, Reticles, Precision measurement

Read Abstract +

Proceedings Article | 19 August 2005 Paper

Improvement in total measurement uncertainty for gate CD control

Benjamin Bunday, Osman Sorkhabi, John Allgair, Youxian Wen, Amy Peterson, Paul Terbeek, Ajit Paranjpe

Proceedings Volume 5878, 58780M (2005) https://doi.org/10.1117/12.616344

KEYWORDS: Critical dimension metrology, Semiconducting wafers, Amorphous silicon, Finite element methods, Metrology, Scatterometry, Data modeling, Oxides, Calibration, Reticles

Read Abstract +

Proceedings Article | 10 May 2005 Paper

Unbiased estimation of linewidth roughness

B. Bunday, J. Villarrubia

Proceedings Volume 5752, (2005) https://doi.org/10.1117/12.599981

KEYWORDS: Line width roughness, Metrology, Line edge roughness, Scanning electron microscopy, Critical dimension metrology, Error analysis, Edge detection, Semiconductors, Line scan image sensors, Transistors

Read Abstract +

Proceedings Article | 10 May 2005 Paper

CD SEM metrology macro CD technology: beyond the average

Aviram Tam, Benjamin Bunday, David Chase-Colin, Michael Har-Zvi, Asaf Dajczman, John Allgair, Di Michelson, Ofer Adan

Proceedings Volume 5752, (2005) https://doi.org/10.1117/12.600133

KEYWORDS: Critical dimension metrology, Semiconducting wafers, Scanning electron microscopy, Process control, Metrology, Etching, Cadmium, Lithography, Line width roughness, Statistical analysis

Read Abstract +

Proceedings Article | 10 May 2005 Paper

Specifications, methodologies, and results of evaluation of optical critical dimension scatterometer tools at the 90nm CMOS technology node and beyond

Amy Peterson, Benjamin Bunday, John Allgair

Proceedings Volume 5752, (2005) https://doi.org/10.1117/12.600115

KEYWORDS: Semiconducting wafers, Finite element methods, Critical dimension metrology, Metrology, Signal to noise ratio, Calibration, Reticles, Lithography, Line width roughness, Interference (communication)

Read Abstract +

Proceedings Article | 24 May 2004 Paper

Dimensional metrology of resist lines using a SEM model-based library approach

Andras Vladar, Benjamin Bunday, John Villarrubia, Michael Bishop

Proceedings Volume 5375, (2004) https://doi.org/10.1117/12.536871

KEYWORDS: Scanning electron microscopy, Electron beams, Model-based design, Silicon, Dimensional metrology, Statistical modeling, Metrology, Monte Carlo methods, Manufacturing, Semiconducting wafers

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Proceedings Article | 24 May 2004 Paper

Determination of optimal parameters for CD-SEM measurement of line-edge roughness

N. Orji, Michael Bishop, Ronald Dixson, Andras Vladar, John Allgair, Benjamin Bunday, Theodore Vorburger, Donald McCormack, John Villarrubia

Proceedings Volume 5375, (2004) https://doi.org/10.1117/12.535926

KEYWORDS: Line edge roughness, Line scan image sensors, Line width roughness, Edge roughness, Image segmentation, Critical dimension metrology, Metrology, Edge detection, Image quality, Tolerancing

Read Abstract +

The measurement of line-edge roughness (LER) has recently become a topic of concern in the litho-metrology community and the semiconductor industry as a whole. The Advanced Metrology Advisory Group (AMAG), a council composed of the chief metrologists from the International SEMATECH (ISMT) consortium’s Member Companies and from the National Institute of Standards and Technology (NIST), has a project to investigate LER metrics and to direct the critical dimension scanning electron microscope (CD-SEM) supplier community towards a semiconductor industry-backed, standardized solution for implementation. The 2003 International Technology Roadmap for Semiconductors (ITRS) has included a new definition for roughness. The ITRS envisions root mean square measurements of edge and width roughness. There are other possible metrics, some of which are surveyed here. The ITRS envisions the root mean square measurements restricted to roughness wavelengths falling within a specified process-relevant range and with measurement repeatability better than a specified tolerance. This study addresses the measurement choices required to meet those specifications. An expression for the length of line that must be measured and the spacing of measurement positions along that length is derived. Noise in the image is shown to produce roughness measurement errors that have both random and nonrandom (i.e., bias) components. Measurements are reported on both UV resist and polycrystalline silicon in special test patterns with roughness typical for those materials. These measurements indicate that the sensitivity of a roughness measurement to noise depends importantly both on the choice of edge detection algorithm and the quality of the focus. Measurements are less sensitive to noise when a model-based or sigmoidal fit algorithm is used and when the images are in good focus. Using the measured roughness characteristics for UV resist lines and applying the ITRS requirements for the 90 nm technology node, the derived expression for sampling length and sampling interval implies that a length at least 8 times the node (i.e., 720 nm) must be measured at intervals of 7.5 nm or less.

Proceedings Article | 24 May 2004 Paper

Results of benchmarking of advanced CD-SEMs at the 90-nm CMOS technology node

Michael Bishop, Benjamin Bunday, John Allgair

Proceedings Volume 5375, (2004) https://doi.org/10.1117/12.535960

KEYWORDS: Semiconducting wafers, Line edge roughness, Scanning electron microscopy, Pattern recognition, Contamination, Finite element methods, Standards development, Metrology, Lithography, Critical dimension metrology

Read Abstract +

The Advanced Metrology Advisory Group (AMAG) is a council composed of the chief CD-metrologists from the International SEMATECH Manufacturing Initiative (ISMI) consortium’s Member Companies and from the National Institute of Standards (NIST). The AMAG wrote and, in 2002, with CD-SEM supplier involvement, updated the “Unified Advanced CD-SEM Specification for Sub-130nm Technology (Version 2002)” to be a living document which outlines the required performance of advanced CD-SEMs for supplier compliance to the 2003 International Technology Roadmap for Semiconductors, and also conveys member companies’ other collective needs to vendors. Through applying this specification during the mid-2003 timeframe, a benchmarking effort of the currently available advanced CD-SEMs has been performed. These results are presented here. The AMAG Unified Specification includes sections outlining the test methodologies, metrics, and wafer-target requirements for each parameter included in the benchmark, and, when applicable, prescribes a target specification compatible with the ITRS and methodologies compatible with the demands of 90nm technology. Parameters to be considered include: •Precision, Repeatability and Reproducibility •Accuracy, Apparent Beam Width and Resolution •Charging and Contamination •Tool-to-Tool Matching •Pattern Recognition and Navigation Accuracy •Throughput •Instrumentation Outputs •Tool Automation and Utility •Precision and Accuracy of Profile Measurement •Precision and Accuracy of Roughness Measurement. Previous studies under this same project have been published, with the initial version of the International Sematech Unified Specification in 1998, and multi-supplier benchmarks in 1999 and 2001. The results for the 2003 benchmark will be shown and compared to the ITRS, and composite viewpoints showing these 2003 benchmark results compared to the past results are also shown, demonstrating interesting CD-SEM industry trends.

Proceedings Article | 15 July 2003 Paper

CD-SEM measurement line-edge roughness test patterns for 193 nm lithography

John Villarrubia, Michael Bishop, Benjamin Bunday, Andras Vladar

Proceedings Volume 5041, (2003) https://doi.org/10.1117/12.485234

KEYWORDS: Line edge roughness, Reticles, Line width roughness, Scanning electron microscopy, Line scan image sensors, Edge roughness, Signal to noise ratio, Binary data, Lithography, Semiconductors

Read Abstract +

Proceedings Article | 10 July 2003 Paper

Applications of image diagnostics to metrology quality assurance and process control

Andras Vladar, Mark Davidson, Andrew Gurnell, James Potzick, Sylvain Muckenhirn, John McIntosh, Robert Larrabee, Alain Diebold, Victor Boksha, Jerry Hutcheson, Oliver Wells, Daniel Cole, Nigel Smith, David Joy, John Allgair, Neal Sullivan, Joseph Pellegrini, Benjamin Bunday, Alexander Starikov

Proceedings Volume 5042, (2003) https://doi.org/10.1117/12.504320

KEYWORDS: Metrology, Diagnostics, Dimensional metrology, Optical lithography, Manufacturing, Process control, Image processing, Critical dimension metrology, Semiconducting wafers, Edge roughness

Read Abstract +

Proceedings Article | 2 June 2003 Paper

Quantitative profile-shape measurement study on a CD-SEM with application to etch-bias control and several different CMOS features

Benjamin Bunday, Michael Bishop, Kevin Lensing, John Swyers

Proceedings Volume 5038, (2003) https://doi.org/10.1117/12.485016

KEYWORDS: Semiconducting wafers, Etching, Calibration, Critical dimension metrology, Deep ultraviolet, Process control, Scanning electron microscopy, Lithography, Photoresist processing, Reticles

Read Abstract +

One goal of CD metrology is to monitor lithographic process control and how it relates to post-etch results. At present, in-fab process control for this purpose is achieved through top-down CD measurements. To acquire profile information requires destructive cross-section SEM measurements or time-consuming AFM measurements. To find height and profile information about a resist or etched structure directly on a CD-SEM, techniques using the combination of in-column beam tilt and stereographic imaging have been developed, implemented and improved on the Applied Materials NanoSEM-3D. This work is an extension of results previously published, although the tool used is greatly improved and the target feature stacks more thorough. The column of the NanoSEM-3D is designed to be able to electronically tilt the incident beam at small angles as it approaches the sample, through bending the beam within the column. Two images can be captured of the sidewall of the feature target, one at a smaller tilt angle and one at a larger tilt angle. Through matching common features between these two images, a reconstructed profile can be mathematically generated. A feature height and sidewall angle can be calculated, and general shape information such as top-rounding, footing and undercutting can also be displayed. To benchmark the effectiveness of this new technique, an experiment has been conducted to quantify the repeatability and reproducibility of height and sidewall angle measurements of lines of resist-on-poly and the resulting etched-poly lines, and correlate these to measurements of the these same profiles using XSEM to determine the accuracy of the technique. This study will span a reasonable lithographic process window. We hope to demonstrate the necessary precision and accuracy capability to non-destructively replace some cross-section work. In applying these techniques to a common etch bias problem, we also hope to demonstrate a strong correlation which can be used to directly predict post-etch behavior and serve as a model for other etch processes, work with which XSEM cross-sections have typically been used until now. The profile measurement technique is also applied to other CMOS features such as etched STI trench, resist and etched contact holes, and resist and etched damascene trenches and vias, with calculated tool precisions for feature height and sidewall angle.

Proceedings Article | 2 June 2003 Paper

CD-SEM measurement line-edge roughness test patterns for 193-nm lithography

Andras Vladar, John Villarrubia, Michael Bishop, Benjamin Bunday

Proceedings Volume 5038, (2003) https://doi.org/10.1117/12.485007

KEYWORDS: Line edge roughness, Reticles, Line width roughness, Edge roughness, Line scan image sensors, Scanning electron microscopy, Signal to noise ratio, Binary data, Lithography, Metrology

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Proceedings Article | 2 June 2003 Paper

Implementation of reference measurement system using CD-AFM

Angela Guerry, Ronald Dixson, Marylyn Bennett, Theodore Vorburger, Benjamin Bunday

Proceedings Volume 5038, (2003) https://doi.org/10.1117/12.483667

KEYWORDS: Semiconducting wafers, Scanning electron microscopy, Standards development, Calibration, Atomic force microscopy, Metrology, Critical dimension metrology, Error analysis, Semiconductor manufacturing, Line edge roughness

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Proceedings Article | 2 June 2003 Paper

Electron beam metrology of 193-nm resists at ultralow voltage

Neal Sullivan, Ron Dixson, Pascal Fabre, Paul Knutrud, Benjamin Bunday, Martin Mastovich, Robert Brandom

Proceedings Volume 5038, (2003) https://doi.org/10.1117/12.487598

KEYWORDS: Critical dimension metrology, Scanning electron microscopy, Atomic force microscopy, Metrology, Electron beams, Data modeling, Contamination, Semiconducting wafers, Systems modeling, Process control

Read Abstract +

Proceedings Article | 2 June 2003 Paper

Specifications and methodologies for benchmarking of advanced CD-SEMs at the 90-nm CMOS technology node and beyond

Benjamin Bunday, Michael Bishop

Proceedings Volume 5038, (2003) https://doi.org/10.1117/12.483663

KEYWORDS: Semiconducting wafers, Scanning electron microscopy, Pattern recognition, Contamination, Line edge roughness, Electron beams, Critical dimension metrology, Metrology, Calibration, Semiconductors

Read Abstract +

Proceedings Article | 16 July 2002 Paper

Quantitative profile-shape measurement study on a CD-SEM with application to etch-bias control

John Swyers, Benjamin Bunday, Marylyn Bennett, Zipora Haberman-Golan, Michael Bishop

Proceedings Volume 4689, (2002) https://doi.org/10.1117/12.473452

KEYWORDS: Semiconducting wafers, Calibration, Etching, Critical dimension metrology, Scanning electron microscopy, Lithography, Line edge roughness, Cadmium, Error analysis, Process control

Read Abstract +

Proceedings Article | 16 July 2002 Paper

Benchmarking of advanced CD-SEMs at the 130-nm CMOS technology node

Michael Bishop, Benjamin Bunday

Proceedings Volume 4689, (2002) https://doi.org/10.1117/12.473444

KEYWORDS: Semiconducting wafers, Scanning electron microscopy, Contamination, Pattern recognition, Metrology, Electron beams, Aluminum, CMOS technology, Semiconductors, Lithography

Read Abstract +

Proceedings Article | 2 June 2000 Paper

Use of fast Fourier transform methods in maintaining stability of production CD-SEMs

Mark Davidson, Benjamin Bunday

Proceedings Volume 3998, (2000) https://doi.org/10.1117/12.386459

KEYWORDS: Scanning electron microscopy, Image quality, Fourier transforms, Visualization, Beam shaping, Metrology, Silicon, Cadmium, Monochromatic aberrations, Image processing

Read Abstract +

Showing 5 of 101 publications

Conference Committee Involvement (15)

Metrology, Inspection, and Process Control XXXVIII

26 February 2024 | San Jose, California, United States

Metrology, Inspection, and Process Control XXXVII

27 February 2023 | San Jose, California, United States

Metrology, Inspection, and Process Control XXXVI

25 April 2022 | San Jose, California, United States

Metrology, Inspection, and Process Control for Semiconductor Manufacturing XXXV

22 February 2021 | Online Only, California, United States

Metrology, Inspection, and Process Control for Microlithography XXXIV

24 February 2020 | San Jose, California, United States

Metrology, Inspection, and Process Control for Microlithography XXXIII

25 February 2019 | San Jose, California, United States

Metrology, Inspection, and Process Control for Microlithography XXXII

26 February 2018 | San Jose, California, United States

Metrology, Inspection, and Process Control for Microlithography XXXI

27 February 2017 | San Jose, California, United States

Metrology, Inspection, and Process Control for Microlithography XXX

22 February 2016 | San Jose, California, United States

Metrology, Inspection, and Process Control for Microlithography XXIX

23 February 2015 | San Jose, California, United States

Metrology, Inspection, and Process Control for Microlithography XXVIII

24 February 2014 | San Jose, California, United States

Metrology, Inspection, and Process Control for Microlithography XXVII

25 February 2013 | San Jose, California, United States

Metrology, Inspection, and Process Control for Microlithography XXVI

13 February 2012 | San Jose, California, United States

Metrology, Inspection, and Process Control for Microlithography XXV

28 February 2011 | San Jose, California, United States

Metrology, Inspection, and Process Control for Microlithography XXIV

22 February 2010 | San Jose, California, United States

Showing 5 of 15 Conference Committees

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