Frontiers of Nanoelectronics Metrologyat NIST

OR: Where’s the Beef?

David Seiler, Chief

Engineering Physics Division, National Institute of Standards and Technology

July 13, 2016

“The National Institute of Standards and Technology (NIST) … lends its metrology expertise. Advancing nanoelectronics requires measuring structures with atomic accuracy, characterizing new materials and molecules, and even measuring the signals from individual electrons – if we can't measure it, we can't make it.”

- SIA_online.ORG

1david.seiler@nist.gov

Agenda

• Introduction and Background

• NIST At-a-Glance

• Some Examples of Frontiers of Nanoelectronics Metrology at NIST• Optical Spectroscopy

• Graphene, 2D Materials, CNTs

• Defect Detection and Identification

• Advanced Microscopy

• Devices and Characterization

• Flexible Electronics

• Summary

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Advanced Electronics Manufacturing(Yes, I Know I am “Preaching” to the Choir)

• Electronics is at the heart and soul of our modern society.

• The electronics industry and its impact on our society is huge.

• The industry is, of necessity, continually moving to new devices based upon new materials and structures, as well as new physics.

• Measurement advances are needed to help enable future electronics

• The measurement challenges are increasingly difficult & the needs exploding.

• Measurement needs are often too large and complex for one company to solve and so precompetitive cooperation is often desired

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“Somewhere, something incredible is waiting to be known.”Carl Sagan (1934 – 1996)

What Lies Ahead for Nanoelectronics?

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AND What Difference Does the Future of Nanoelectronics Make?

• Why does investment in nanoelectronics research matter? Nanoelectronics is a game-changer for the industry and the country – a disruptive technology that could alter the dynamic of market leadership. The current chip technology, which has been used for four decades, is predicted to reach its scaling and power dissipation limits by 2020. Nanoelectronics holds the promise of a successor technology. The country that discovers this breakthrough research is likely to reap the related economic benefits. The U.S. federal government’s research resources, specifically the NSF and NIST are critical to this effort.

American Competitiveness: The Role of Research and Development Testimony before the U.S. House Committee on Science, Space, and Technology

Richard K. Templeton, Chairman, President and CEO Texas Instruments Incorporated, February 6, 2013

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NIST – Who Are We and What Do We Do

• Founded in 1901, NIST is a non-regulatory federal agency within the U.S. Department of Commerce. NIST's mission is to promote U.S. innovation and industrial competitiveness by advancing measurement science, standards, and technology in ways that enhance economic security and improve our quality of life.

• NIST carries out its mission through the NIST Laboratories, who conduct world-class research, often in close collaboration with industry. That mission helps advance the nation's technology infrastructure and helps U.S. companies continually improve products and services.

• So how does a measurement agency support innovation? If you know how to measure things, you can begin to learn how to control them, design them, shape them, and eventually manufacture them. And that’s one aspect of technological innovation.

• The truth of the matter is that measurements permeate every aspect of our lives.

• NIST has a long history working with the semiconductor/electronics industry in helping advance measurements and standards that help enable innovation and economic competitiveness.

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NIST At-a-Glance

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Major Assets, Partnerships, People, Budget

2 Large Research

Campuses

FY 2016 Appropriations.

$964 Million

PartnershipsIn Every

State

Gaithersburg, MD– 62 bldgs. 578 acresBoulder, CO—26 bldgs., 208 acres

60 Manufacturing Extension Centers10 joint institutes/Centers of Excellence

NIST labs, $690MIndustrial Technology Services, $155 MConstruction of Research Facilities, $119 M

People:Employees

& Associates

~3,400 Federal Employees~3,700 Guest Researchers & other NIST Associates ~400 NIST Staff on ~ 1,000 standards committees

Additional Resources~ $120 M from other government agencies~ $50 M from reimbursable services

NIST Impacts Advanced Nanoelectronics Throughout All Its LaboratoriesNIST’s Role: To develop innovative measurements and critical metrology infrastructure that enables a broad range of new devices and architectures for the U.S. electronics and information technology industries allowing them to break through technological barriers making possible critical innovations that will keep these industries competitive in the global economy.

Todays Frontiers of Nanoelectronics at NIST Talk Focused on:

• Optical Spectroscopy

• Graphene, 2D materials, CNTs

• Defect Detection and Identification

• Advanced Microscopy

• Advanced Device Characterization

• Flexible Electronics

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Challenge: Science and Engineering at the Atomic and Molecular Level

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• Nanoscale Science and Technology Involves the Atomic and Molecular Level• fundamental understanding of phenomena and materials at the nanoscale• fabrication and use of structures, devices, and systems that have novel

properties and functions because of their small size• control of matter and processes at the atomic and molecular level• Integration of nanoscale materials and structures into larger materials

components, systems, and architectures• 3D becomes critical

• Addressing the measurement challenges associated with atom-technology for ultimately scaled Si electronics • Dopant position and device variability• Atomic scale defects• Single-atom transistors

• Exploring innovative technologies to move beyond traditional CMOS devices

• Atomic tunnel-transistors• Single-electron memories

• Manufacturing at the atomic scale

• A flexible platform to make atomically precise test structures.

• Ultimately scaled traditional Si devices and quantum structures

• Measurements for atom technology• The measurement science and methods needed to characterize single and few atom

devices.• Atomic resolution of structure • Atomic variability and defects• Measurement methods that account for device perturbation

• Modeling• Atomistic models to interpret and predict device behavior with atomic precision.

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Every atom counts!

Frontiers of Atomically Precise Fabrication and Device Characterization

Title - Metrology/Technique/ToolNOTE: Try and insert one good figure, photo, data, etc. somewhere to make the slide interesting to look at

• Objectives/Difficult Challenges• [What are you trying to do?]

• [clear, concise]

• …

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• Major Accomplishments• …

• …

• …

• Uniqueness of NIST Approach• [What is the problem? What’s new?]

• …

• …

• Impact, Benefits, and Collaborations• Where’s the beef

• …

• …

Contact: John Doe (john.doe@nist.gov)

Band offset measurements by internal photoemission and spectroscopic ellipsometry• Objectives/Difficult Challenges

• Electronic band offsets at a heterojunction are critical parameters required for optimizing the performance of advanced electronic devices.

• Internal photoemission (IPE) combined with spectroscopic ellipsometry (SE) can determine the band offset of a buried interface.

• The challenge is to ascertain the narrow (few hundred meV) band offsets of heterojunctions of compound and two-dimensional semiconductors

• Major Accomplishments

• Uniqueness of NIST Approach

• Innovated method using graphene as an semitransparent electrode to determine narrow band offsets of 2D-heterojunctions.

• Consequently IPE combined with SE can determine full band alignment structure of a buried interface.

• Impact, Benefits, and Collaborations• Publication in high impact peer reviewed journals.

• W. Li et al., Applied Physics Letters, 105, 213501 (2014).

• K. Xu et al., Nano Letters 13, n. 1, pp. 131-136, (2013)

• R. Yan et al., Applied Physics Letters, 102, 123106, (2013)

• Q. Zhang et al., Applied Physics Letters, 102, 012101 (2013)

• Measurement method copied by ND to study critical heterostructures for their

programs.

• Collaborations with top NRI/STARNET universities (Notre Dame, Cornell, Penn State,

UCLA, Purdue) and ARL and Intel.

Contact: Nhan Nguyen (nhan.nguyen@nist.gov)

Band offsets of Tunnel FETs and alternate channel FinFETs

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World Class Laboratory for Raman Spectroscopy of Graphene, 2D Materials, CNTs

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ObjectiveConduct fundamental research to develop, validate, and advance the measurement science of Raman spectroscopy to determine the properties of novel nanomaterials.

Nanoelectronic Material Systems• Carbon nanotubes; high-quality, single-

wall and polymer-embedded multiwall• Graphene, 2D di-chalcogenides and

their heterostructures• Strain engineered nanomaterials• Conducting polymers

Uniqueness of NIST ApproachRaman spectroscopy is a widely used tool to characterize nanoelectronic materials, yet validated, quantitative studies are limited. NIST is working collaboratively within and with external partners (academia, industry and other international metrology institutes) to develop the measurement science needed to enable SI-traceable Raman spectroscopy and advanced Raman techniques to extract the information rich data. Outputs include designer facilities, publication and standards activities within ISO TC 229 nanotechnology. Below are examples of recent collaborators:

Unprecedented Raman Facilities and Capabilities• Resonance Raman – Tunable laser excitation throughout

the visible• Temperature dependent Raman (4 K to 400 K) for thermal

conductivity measurements• Raman mapping capabilities with diffraction limited spot

size• Low frequency Raman for monitoring phonons and layer

coupling • Hyphenated Raman Techniques:

• Magneto-Raman – Capable of collected Raman scatter while the sample is held at specific temperature and magnetic Field (0 to 9 T) in either Faraday or Voight geometry

• AFM-Raman – Co-located topography and chemical information with nanometer special resolution

• Device transport (under development) for in-operando Raman measurements at field and temperature

Contact: Angela R. Hight Walker (angela.hightwalker@nist.gov)

New Wafer-Level Electrically Detected Magnetic Resonance Method for Atomic Scale Defects

• Objectives/Difficult Challenges• Identify critical atomic-scale defects DIRECTLY in electron

devices via magnetic resonance spectroscopy.

• Conventional EDMR approaches are simply incompatible with the needs of modern rapid technology development.

• Uniqueness of NIST Approach• “performing an MRI on an electron device with nothing more

than a permanent magnet, wafer probes, and an antenna”

• Drastically simplified system – ability to integrate into standard wafer prober.

• Rapid-scan frequency swept high sensitivity detection.

• Impact, Benefits, and Collaborations• Identification of performance-limiting defects in ANY

electron device structure (tunnel-FETs, neuromorphic RRAM, 2-D devices, etc.)

• Ongoing collaborations with industry leading semiconductor companies to bring technique online.

Contact: Jason Ryan (Jason.Ryan@nist.gov)

ESR

Abs

orpt

ion

[Arb

. Uni

ts]

Magnetic Field [T]

Pb0 E′

K

Frequency swept EDMR of SiC diode (200 Hz sweep rate)

• Major Accomplishments• Complete EDMR spectrometer/commercial wafer

probe station integration.

• World’s first demonstration of rapid-scan frequency-swept EDMR. on SiC MOSFETs.

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Scatterfield Optical Microscopy for 3-D Nanostructure Imaging and Defect DetectionObjectives/Difficult Challenges

• Resolving critical issues in deep subwavelength linewidth and defectmetrology for the U.S. semiconductor industry.

• Enabling the world’s smallest multi-dimensional measurements of objects using optical imaging, providing quantitative information from scattered light images at resolutions previously thought impossible.

Major Accomplishments

• Rigorously fitting the full 3-D scattered light field to measure nanometer-scale topography for features sized less than l/25 with sub-nm parametric uncertainties (see figure).

• Revealing “killer” defects in semiconductor manufacturing through engineering of the illumination and collection paths.

• Combining multi-tool measurements into a monolithic, hybrid result using techniques that have been adopted by industry for metrology in high-volume manufacturing for current and future sub-10 nm sized devices.

Uniqueness of NIST Approach

• Quantitative Optical Microscopy, combining bright-field optical microscopy with fundamental physics-based modeling and simulation to realize fully optimized dimensional measurements.

• Assessing computationally how to optimize the optical scattering from patterned defects, tailoring the polarization and angular illumination for Defect Metrology; augmented with a world-class l=193 nm microscope.

• Pioneering the foundational statistics required to combine and optimize a variety of measurement methods to improve uncertainties, to as small as the width of a few atoms, called Hybrid Metrology.

Impact, Benefits, and Collaborations

• ITRI (Taiwan) – Our techniques “becoming commonplace in many new-generation advance process control …”

• Recognized as world-leaders in the hybrid metrology field. R&D 100 Award for “Quantitative Hybrid Metrology” (2013).

• Intel – [defect work] “… both fundamentally unique and technically important … helped spur industry wide interest.”

• Externally funded collaboration with a U.S. Semiconductor Manufacturer and additional collaborations with suppliers to the Semiconductor Industry.

Contact: Bryan Barnes (bryan.barnes@nist.gov)

Defect (green) detection in through-focus volumetric imaging using intensity and nearest-neighbor thresholding to exclude noise (red) at l = 193 nm

Defect

Defect

Noise

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Stroboscopic Transmission Electron MicroscopeTurn every TEM into a high speed camera for atoms

• Objectives/Difficult Challenges• In operando, dynamic processes are

fleeting, hard to observe

• Couple spatial (atomic) resolution with high temporal (sub ps) resolution

• Incorporate synchrotron micro-cavity chopper into TEM optical column

• Uniqueness of NIST Approach• Laser-free design

• Large probe currents, high duty cycles

• Continuously variable strobe-rate (2 to 20 GHz)

• Potential for down-sampling to kHz with advanced cameras

• Impact, Benefits, and Collaborations• Atomic images of nanoelectronic switches

• Magnetic spin waves can be recorded

• Compatible with conventional TEMs (large market impact)

• Partners: Euclid Techlabs, IDES, Brookhaven NL

Contact: June Lau (june.lau@nist.gov)

CW beam

cavity

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Accuracy in 3D Atom Probe Tomography

Need

• ITRS Roadmap stated that current chemical measurements will not adequately support the next generation of CMOS nanofabrication

• Accurate atomic and nano-scale quantitative chemical analyses in nano-materials and complex structures needed.

Major Accomplishments• Implicated detector dead-time as a major ion signal loss

mechanism in multi-hit data.

• Demonstrated that dead-time affects the measured charge-state ratio and isotopic abundances.

• Demonstrated that charge state ratio control can be used to improve data yield in multi-phase specimens.

• Identified factors limiting the mass resolution.

Objectives• Develop a robust understanding of the atom probe

instrument performance to meet the needs and concerns of relevant stakeholders in industry, academia, and government.

• Understand the factors that impact the accuracy of quantitative analysis of elements and isotopes.

• Develop tools and standards to improve the measurement accuracy in chemical analyses.

Impact, Benefits, and Collaborations• > 9 collaborations, 2 funded proposals,3+ peer reviewed

journal articles, 15+ conference presentations, co-organized 2 atom probe standards meetings

Contacts: Eric Steel (eric.steel@nist.gov ) & Fred Meisenkothen (frederick.meisenkothen@nist.gov ) 17

Through-focus Scanning Optical Microscopy (TSOM) Transforms conventional optical microscopes into three-dimensional shape metrology tools

Objectives/Difficult Challenges• Low cost, high-throughput, 3D

shape metrology • Sub-10 nm to over 100 mm targets• Sub-nm measurement resolution• Uses conventional microscopes.

Major Accomplishments• Sub-20 nm defect with l=546 nm• 3D shape with sub-nm resolution• Nanoparticle size• Sub 5 nm step height • Sub-7 nm CD (simulations)• HAR, TSV process monitoring• Sub-200 ms analysis time

Uniqueness of NIST Approach• Uses three-dimensional optical intensity data• Uniquely identifies the type of dimensional

variation • Does not require complicated optical

simulations for process control• Optical cross-correlation: nearly eliminated• Low-quality microscopes can be used• Can be used with isolated targets (no need for

repeated structures)

Impact, Benefits, and Collaborations

• ITRS 2013/2014• SEMI document for 3D S-IC structures• SEMATECH includes for memory / HAR /CD metrology

applications• SAMSUNG Electronics developed and applied for two

patents on TSOM• Highlighted by SPIE Newsroom and others• Collaborations: SEMATECH, Intel, Veeco, CEA/LETI

(France), CMTI (India), Orbotech, Dolomite Ltd.

Contact: Ravi Kiran Attota (Ravikiran.Attota@nist.gov)18

Objectives/Difficult Challenges

• Research and develop measurement techniques and standards for critical needs for SI traceable nanometrology, process and quality control [clear, concise]

• Provide dimensional calibrations from micrometers to 0.1 nm.

Major Accomplishments

• World-class performance (standard uncertainty) has been achieved in both step height (5 ×10-3) and pitch (6 ×10-4) interlaboratory comparisons.

• Sub-1 nm linewidth uncertainties (best in the world)• CD-AFM contour extraction methods for semiconductor dimensional

metrology (first in the world)• First principles fundamental understanding of cylindrical CD-AFM tip-

sample interaction (first in the world)

Uniqueness of NIST Approach• Fundamental SI traceable AFM dimensional metrology research and

development.• Dimensional metrology standards development and characterization.• Unique Specialized Instruments:

• Traceable Atomic Force Microscope (T-AFM)

• Critical dimension AFM: Dual axes AFM for advanced semiconductor 3D features. SI traceable through silicon lattice imaging.

Impact, Benefits, and Collaborations

• Accurate 3D metrology of semiconductor devices such as finFETs, and contours.

• Reference and hybrid metrology developed by NIST has been adopted by industry (based on NIST traceable AFM measurements)

• Calibration measurements for vendors underpin their metrology program and are transferred to hundreds of samples a year.

• Collaborators: Instrument and calibrations sample vendors, IC and tip manufacturers such as: ASM, Bruker AFM, IBM/GF, FEI, VLSI, Nanotools among others.

T-AFM: SI traceable AFM with integrated displacement interferometry. For characterizing nanoscale surface features and defects, and calibration artifacts. The only instrument of this type in the country.

Contact: George Orji (george.orji@nist.gov) or Ron Dixson(Ronald.Dixson@nist.gov)

Traceable AFM Scanning Probe Nano-characterization

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Ultra Fast Electrical Test System for Resistive Random Access Memory (RRAM)

• Objectives/Difficult Challenges• Development of high speed characterization metrology

to study resistive random access memory (RRAM) devices.

• Controlling the fast forming transients, which determine the switching characteristics, are critical to commercializing this promising memory technology.

• Major Accomplishments• Custom program and verify algorithm implemented in

hardware - relationship between endurance and switching.

• Smart optimization of forming and switching conditions to maximize memory window.

• Forming energy metric developed to track filament viability.

• Uniqueness of NIST Approach• Compliance-free forming and switching of advanced RRAM

devices using ultra-short voltage pulses (picoseconds).

• In-house development of ultra-fast test systems to monitor and control transient resistance changes.

• Impact, Benefits, and Collaborations• Enable commercialization by drastically reducing device to

device variability.

• Collaborations with industry leading semiconductor companies to bring technique online.

Contact: Jason Ryan (Jason.Ryan@nist.gov)

50Ω

1pF

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Physical Properties of New Electronic Materials & DevicesObjective: Accurate mobility characterization for new electronic devices based on novel materials• There is an unprecedented worldwide effort to create

novel materials, e.g. organic, 2D, etc.• Charge carrier mobility remains a key parameter used to

identify and benchmark materials• Mobility is typically determined by building a field-effect

transistor (FET), but this approach is indirect and model dependent; yielding inflated device mobility

• Overestimates as large as 10X have been seen

Major Accomplishment: New measurement and model to disentangle charge injection and transport for FETs with non-ideal characteristics

Uniqueness: Classical FET models assume ideal device behavior; simple model corrections do not capture the physics

Impact: This work has reset mobility benchmarks and revealed the critical role of contacts on FET operation

Contact: David J. Gundlach (david.gundlach@nist.gov)

• Established measurements and models to accurately extract true mobility and reveal the competition between contact and channel resistance

• NIST researchers identified previously unknown error as large as 1000% in estimated mobility

• NIST researchers showed poor contact formation and non-linear charge injection process to be the source of non-ideal behavior

Emily G. Bittle, et al., Nature Commun. 7, 10908 (2016)

Ganapathi et al., IEEE EDL, 37, pp. 797-800 (2016)

• Same mobility overshoot is observed in FETs based on novel 2D electronic materials

McCulloch et al., Science, 352, pp. 1521-1522 (2016)

• Featured in recent Science Perspective

Bittle, et al., Nature Commun. 7, 10908 (2016)

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• Resolution

• molecular to atomic spatial scales and short temporal scales

• Sensitivity and Specificity

• Molecular/atomic level sensitivity & specificity & simultaneous imaging and identification

• simultaneous multiple probes (spectroscopies, etc.) for chemical and physical properties

• 3-D nano-characterization capability, atom by atom, or molecule by molecule, over many thousands of atoms.

• Increase knowledge of the fundamental physical understanding of materials and devices

• Understanding trade-offs of signal-to-noise ratio vs. speed in measurements

• Supporting theories, models, methods, standards, data, uncertainty analyses

• Interdisciplinary research teams are critical

• Innovative, practical, new tools & measurements are critical for advancing the future of nanoelectronics

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“This is an amazing time to be a technologist. Just think of all the tools and components we have at our disposal--technology so powerful that our leverage is limited only by our imagination and creativity...We can look forward to a millionfold increase in the power of microelectronics...”

- Arno Penzias, vice president and chief scientist, Lucent Technologies, Bell Labs Innovations, 1999

Summary: NIST Measurements for Advanced Electronics Enable Future Innovations

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Craig Barrett, formerly

President, Intel

Mark Melliar-Smith, formerly President

and CEO of SEMATECH

Dennis Buss, VP, Silicon Tech. Development, Texas Instruments

> 235 attendees> 295 attendees> 280 attendees

Some Keynote Speakers

Bob Helms, formerly

President and CEO of SEMATECH

> 200 attendees

Michael Polcari, President and CEO

of SEMATECH

> 250 attendees > 230 attendees

Mark Durcan, COO of Micron

Proceedings Document Metrology Advances

> 175 attendees

Tze-Chiang (T.C.) Chen, IBM Fellow and VP,

Science & Technology

Michel Brillouet, Senior Advisor,

CEA-LETI

> 145 attendees > 165 attendees

Mike Mayberry, VP, Intel

Archived Papers and Talks Available on-line:www.nist.gov/pml/div683/conference/archives.cfm

> 140 attendees

Klaus von Klitzing, Max-Planck-Institut FKF

Focal Point for Frontiers of Characterization and Metrology for Nanoelectronics: A Major Conference Held Every Two Years

2017 Frontiers of Characterization and Metrology for Nanoelectronics International Conference

• March 21 – 23, 2017 at the Monterey Marriott, California• Committee includes leaders from NIST, Intel, Texas Instruments, CEA-Leti,

NSF, Micron, Global Foundries, TSMC, and more!• Interested in advancing the next frontiers of characterization and

metrology?• Join the organizing committee• Organize a tutorial session• Suggest critical frontier areas for the conference to highlight• Submit a paper

For more information contact david.seiler@nist.gov• Or see me after the talk

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www.nist.gov/pml/div683/conference/