The CNST News

Centuries-Old Mathematical Theorems Applied to Nanoscale Measurements

Efficient Piezoelectric MEMS Sensors

On-Chip Resonator Produces Ultra-Short Light Pulses 

Nanowire Lithium-Ion Battery

S P R I N G 2 0 1 2 W W W . N I S T . G O V / C N S T

Counting Electrons One at a Time
P A G E 2

I N T H I S I S S U E

Nanowire Li-Ion 

Battery

3

Characterizing 

Nanoparticle 

Shape

3

Coupling Light 

into a Surface 

Plasmon

4

Efficient Piezoelectric Material 

for MEMS Sensor

4

Single Electron 

CMOS NanoTransistors

5

Electrical Contacts in Nanomaterials5

Resonator Produces Light Puls6

Theory Describes 

Electromagnetic 

Momentum Density in Matter

6

New Process for 

Fabricating Optical Gratings

7

New NanoFab 

Staff

7

S P R I N G 2 0 1 2 W W W . N I S T . G O V / C N S T

The month of May marks the fifth anniversary of the establishment of the NIST Center for Nanoscale Science and Technology (CNST) so it seems appropriate to review how far we have come. In a relatively 

short time, the CNST has become a widely used and highly productive facility, serving the country as a major national resource for nanoscale measurement and fabrication methods and technology. Growing from 

an initial staff of about twenty in 2007, this summer we will be bursting at the seams with over 120 people, 

including over 50 postdoctoral and student researchers—the next generation of nanotechnologists. 

The commitment of our staff combined with the growth in our 

measurement and fabrication capabilities has led to notable yearover-year increases in the CNST’s impact. In fiscal year 2011, 

1402 researchers participated in CNST projects, a 45 % increase 

over 2010. These researchers represented 280 academic, government, and industrial institutions from 42 states, the District 

of Columbia, and 26 different countries. Of these institutions, 

79 were private-sector companies, a 49 % increase over 2010.

We have added major new capabilities in both commercial tools 

and beyond state-of-the art instrumentation. In the NanoFab, 

recent acquisitions have focused on tools designed to support experimental processes that remain aligned 

with industrial production methods. The cleanroom’s new photolithography suite, opening next month 

(June 2012), includes a new high-speed ASML stepper, a spin coater, and an automatic developer. This 

suite will also consolidate in one bay most of the Center’s contact lithography equipment, including ovens 

and two contact mask aligners. Notable new capabilities recently added to our research labs include an 

environmental scanning transmission electron microscope for in situ observations of the structure and 

chemistry of dynamic processes during gas-solid interactions, as well as a multifunctional instrument capable 

of simultaneously providing correlated topological, chemical (via infrared spectroscopy), thermal, and mechanical property maps with a spatial resolution below the diffraction limit of infrared radiation.

The rapid annual growth in research participation is 

reflected in a concomitant growth in technical output, with 145 publications from our research participants appearing in fiscal year 2011, representing a 

54 % increase over 2010. These publications included 65 co-authored by CNST staff members, a 55 % 

increase.

We are also very happy to report that in fiscal year 

2011, CNST’s own Henri Lezec received the prestigious Julius Springer Prize, which recognizes researchers who have made an outstanding and innovative contribution to the fields of applied physics, 

for his "pioneering achievements in nanoscale physics and applications." And, Kartik Srinivasan was 

presented with the Presidential Early Career 

Awards for Scientists and Engineers for developing measurement methods to probe strong light-matter 

interactions in semiconductor optical cavities, and for developing processes to fabricate low-loss, on-chip, 

nanophotonic devices. This award is the highest honor bestowed by our government to science and engineering professionals in the early stages of their independent research careers.

I invite you to participate in research at the CNST that will continue the development of nanotechnology 

“from discovery to production,” either by using our NanoFab or collaborating with one of our instrumentation scientists. To learn more about our research opportunities, our growing capabilities, and our accomplishments, visit us on the web at www.nist.gov/cnst. 

–Robert Celotta 

From the Director 

The growth in research 

participation is 

beginning to be 

reflected in 

publications, with the 

number of publications 

increasing by 54 % in 

2011. 
P A G E 3

S P R I N G 2 0 1 2

plex, neither electrical measurements nor post-mortem analysis 

using analytical electron microscopy 

have been sufficient to explain why 

charge capacity fades rapidly in 

some battery types or why other 

batteries fail abruptly. By fabricating batteries measuring less than a 

micrometer in diameter and approximately seven micrometers in 

length, the researchers were able 

to mount complete batteries inside 

a transmission electron microscope 

and image changes in the internal 

battery microstructure during electrochemical cycling. To fabricate 

these batteries, the researchers 

developed a technique using silicon 

nanowires as scaffolding on which 

the current collectors, cathode, 

electrolyte, and anode layers were 

deposited using semiconductor 

processing methods. This structure 

allowed them to monitor charge 

and discharge cycles while observing physical and chemical changes in 

the battery at the nanoscale, and to 

make an initial important discovery: 

LiPON, the solid electrolyte used in 

Researchers from the CNST and 

the University of Maryland have 

fabricated nanoscale rechargeable 

lithium-ion batteries (LIBs), enabling 

them to perform measurements 

directly correlating electrochemical 

activity with chemical and morphological changes occurring inside a 

battery during charge transfer. This 

experimental platform should overcome the limitations of external 

electrical measurements and postmortem analysis that have been 

slowing the development of new, 

higher performance battery materials. LIBs are the most efficient 

electrochemical energy storage 

technology used in portable consumer electronics and are expected 

to be the dominant power source 

for electric vehicles in the near 

future. However, the high costs, 

limited range, limited lifespan, and 

safety concerns associated with 

LIBs constitute formidable obstacles 

to increasing the market penetration of electric vehicles. Because 

the materials and structures that 

constitute LIBs are extremely commost commercial thin 

film Li-ion batteries, fails 

when its thickness is 

reduced below approximately 300 nm. This 

failure is marked by the 

rapid (about 2 hour) self

-discharge of the battery, accompanied by 

bubble formation believed to be caused by 

oxygen gas evolution 

that was observed insitu with a transmission 

electron microscope. 

The researchers believe 

that their experimental 

platform will provide 

insights into battery 

failure mechanisms, improve solid 

electrolytes, and advance the development of high energy density Liion batteries based on nanowires. 

Electrolyte stability determines scaling limits 

for solid-state 3D Li-ion batteries, D. 

Ruzmetov, V. P. Oleshko, P. M. Haney, H. J. 

Lezec, K. Karki, K. H. Baloch, A. K. Agrawal, 

A. V. Davydov, S. Krylyuk, Y. Liu, J. Huang, M. 

Tanase, J. Cumings, and A. A. Talin, Nano 

Letters 12, 505-511 (2011). 

Researchers Fabricate Solid-State Nanowire Lithium-Ion Battery 

A transmission electron microscope was 

used to watch individual nanosized batteries with electrolytes of different thicknesses charge and discharge. The researchers 

discovered that there is likely a lower 

limit to how thin an electrolyte layer can 

be made before it causes the battery to 

fail. 

In the few years 

since its 

inception, the 

CNST has 

become a major 

national 

resource for 

nanoscale 

science and the 

development of 

nanotechnology, 

and the only 

national 

nanocenter with 

a focus on 

commerce. 

Combining Centuries-Old Mathematical Theorems to Efficiently Characterize 

the Shape of Nanoparticles 

CNST researcher Gregg Gallatin 

has shown that a mathematical 

technique combining Gauss’s Law 

with Fourier transforms can be 

used as a starting point to solve a 

wide variety of standard problems 

in mathematics and physics. Because of the ubiquity of digital data 

derived from Fourier transforms, 

this technique is likely to find broad 

application to a range of physical 

science and engineering measurements. Using the technique, Gallatin demonstrated how Porod’s 

law, which describes how x-rays 

scatter from small sphericallyshaped particles, can be re-derived 

and extended to the broader case 

of particles that are nonspherical, 

thereby providing a powerful and 

useful approach for determining the 

shape of nanoparticles using x-ray 

scattering. He then demonstrated 

that this approach can be further 

extended to visible light scattering, 

which depends on the moments of 

the nanoparticle shape and therefore provides a more general method for measuring nanoparticle 

shape from scattering data. The 

technique of combining Gauss’s 

Law with Fourier transforms can 

also be applied to the classical physics problem of Fraunhofer diffraction, providing an explicit formula 

for the diffraction pattern of arbitrary polygonal-shaped openings in 

an opaque screen in terms of the 

vertices of the polygon. It is also 

applicable to a variety of mathematics problems, including the Hopf 

Umlaufsatz, which states that the 

angle of the tangent along a simple 

smooth closed curve turns by 360 

degrees when making a complete 

circuit around the curve; Stokes’ 

Law, which relates integrals over an 

area in two dimensions to the one 

dimensional curve bounding the 

area; and the isoperimetric inequality, which states that a circle is the 

shape that encloses the largest area 

for a given circumference. Given 

the simplicity and generality of this 

mathematical technique, Gallatin 

believes that it can be applied to 

many other problems as well. 

Fourier, Gauss, Fraunhofer, Porod and the 

shape from moments problem, G. M. Gallatin, 

Journal of Mathematical Physics 53, 013509 

(2012). 

3 μm

300 nm

Li-ion Nanobattery
P A G E 4

Scanning 

electron 

micrograph of a 

grating coupler. 

The gold film on 

mica is 

atomically 

smooth except at 

the grain 

boundaries. 

Efficiently Coupling Light from a Plane Wave into a Surface Plasmon Mode 

CNST researchers 

have made a 

grating coupler that 

transmits over 

45 % of the 

incident optical energy 

from a plane 

wave into a 

single surface plasmon polariton 

(SPP) mode propagating on a flat 

gold surface, an order-of-magnitude 

increase over any SPP grating coupler reported to date. Surface 

plasmons are propagating waves of 

light tightly confined to a metal 

surface via coupling with oscillating 

electrons in the metal. SPPs have 

been used to route signals for optical interconnects and to concentrate light for molecular sensors. 

The researchers’ simple integrated 

coupler may improve performance 

and lower packaging costs for such 

devices and may also enable highfrequency optical connections between devices over longer distances. The researchers developed an 

analytical model of the coupling 

process to optimize the depth, 

width, and period of the identical 

rectangular grating grooves that 

they nanofabricated on a gold surface. Optical measurements on 

different sets of gratings confirmed 

the model’s prediction that the 

highest efficiency would occur with 

“critical coupling,” when the scattering by the grating grooves is 

matched to the intrinsic losses of 

the SPP propagating on the grating. 

Because these couplers can be used 

to excite surface plasmonic devices 

more efficiently, the researchers 

expect that they will enable the 

development of a variety of future 

on-chip devices. 

An efficient large-area grating coupler for 

surface plasmon polaritons, S. T. Koev, A. 

Agrawal, H. J. Lezec, and V. A. Aksyuk, Plasmonics, published online November 2011, 

1-9 (2011). 

resonance frequency measurements 

and developed engineering models 

of the cantilevers to determine how 

much they would bend at different 

voltages, confirming that the experimental observations were due to

the piezoelectric's performance. 

He also modeled silicon systems 

that achieve similar effects using 

electrostatic attraction to compare 

and highlight the benefits of piezoelectric actuation. “Our work 

shows definitively that the addition 

of PMN-PT to MEMS designed for 

sensing or as energy harvesters will 

provide a tremendous boost to 

their sensitivity and efficiency,” says 

Aksyuk, “a much bigger 'bend for 

your buck,' you could say.”

Giant piezoelectricity on Si for hyperactive 

MEMS, S. H. Baek, J. Park, D. M. Kim, V. A. 

Aksyuk, R. R. Das, S. D. Bu, D. A. Felker, J. 

Lettieri, V. Vaithyanathan, S. S. N. Bharadwaja, N. Bassiri-Gharb, Y. B. Chen, H. P. Sun, C. 

M. Folkman, H. W. Jang, D. J. Kreft, S. K. 

Streiffer, R. Ramesh, X. Q. Pan, S. TrolierMcKinstry, D. G. Schlom, M. S. Rzchowski, R. 

H. Blick, and C. B. Eom, Science 334, 958 -

961 (2011). 

A team of researchers from the 

University of Wisconsin-Madison, 

Penn State, University of California, 

Berkeley, University of Michigan, 

Cornell, and Argonne National 

Laboratory, 

working with 

the CNST’s 

Vladimir 

Aksyuk, have 

succeeded in 

integrating a 

new, highly 

efficient piezoelectric material, lead magnesium niobate-lead titanate (PMNPT), into a silicon microelectromechanical system (MEMS). This 

development could lead to significant advances in sensing, imaging, 

and energy harvesting. Piezoelectric materials, such as quartz, expand slightly when fed electricity 

and, conversely, generate an electric charge when squeezed. Quartz 

watches take advantage of this 

property to keep time: electricity 

from the watch's battery causes a 

piece of quartz to expand and contract inside a small chamber at a 

specific frequency, and circuitry 

converts that motion into the displayed time. Piezoelectric materials 

are also found in sensors in sonar 

and in ultrasound systems, which 

use the same principle in reverse to 

translate sound waves into images. 

Although conventional piezoelectric 

materials work fairly well for many 

applications, researchers have long 

sought to develop new ones that 

expand more and produce higher 

voltages. More reactive materials 

would make for better sensors and 

could enable new technologies such 

as “energy harvesting” to transform 

the energy of walking and other 

mechanical motions into electrical 

power. The researchers developed 

a way to incorporate PMN-PT into 

tiny cantilevers on a silicon base, 

and demonstrated that PMN-PT 

could deliver two to four times 

more movement with greater 

force—while using only 3 volts—

than most rival materials studied to 

date. CNST’s Aksyuk conducted 

Multi-Institutional Collaboration Integrates New Efficient Piezoelectric 

Material into MEMS Sensors 

False color scanning electron micrograph of a lead 

magnesium niobate-lead titanate 

1 μm

5 μm
Fabrication of CMOS-Quality Single-Electron Nano-Transistors 

S P R I N G 2 0 1 2 P A G E 5

Researchers Publish a Detailed Review of Electrical Contacts in One and Two 

Dimensional Nanomaterials 

NIST researchers have fabricated 

multi-level silicon nano-MOSFET's, 

which at low temperatures can 

measure or control the motion of 

single electrons. This advances 

their ongoing efforts to develop 

both electrical standards based on 

the charge of the electron and single electron devices (SEDs) for 

quantum computing applications.

SEDs have the ability to move electrons around one-by-one in solidstate devices; for comparison, a 

typical household current of 1 Ampere corresponds to 1019 electrons 

passing per second. While researchers have been fabricating and 

measuring SEDs made from aluminum and aluminum oxide for a 

number of years, recently interest 

has developed in making these devices with silicon using standard 

CMOS processing techniques in 

order to improve device stability 

and speed. Physicist Neil Zimmerman and a team of researchers 

from the NIST Physical Measurement Laboratory have been trying 

to make such devices elsewhere for 

several years. However, the devices require a process flow with over 

80 individual processing steps, all of 

which must work reliably to make 

functioning devices. By working 

with a process engineering team in 

the CNST NanoFab, they have now 

succeeded in making robust SEDs 

that show good single electron 

characteristics at low temperatures. These devices have only 

small inhomogeneity in their 

threshold voltages, high robustness 

with respect to application of large 

voltages, and small charge offset 

drift. According to Zimmerman, 

the multi-step process was “a tourde-force in nanofabrication at a 

research user facility. The reliable 

processes we developed with 

NanoFab staff allowed the project 

to go forward, both in terms of the 

integration ability to make multilevel complex nano-transistors, and 

the ability to reproducibly grow 

high quality 

insulating 

films.”

The researchers 

are currently fabricating singleelectron 

turnstiles in 

order to 

measure the 

error rate 

of passing 

electrons one-by-one and fabricating double quantum dots with 

charge sensors for use in quantum 

coherence experiments. They 

believe these devices will enable 

fundamental current standards at 

higher values of current, and development of Si-based qubits for use in 

quantum computing . 

For more information, contact 

neil.zimmerman@nist.gov. 

with unique properties. The kinetics and thermodynamics of metal/

nanostructure interfaces also differ 

from those of the bulk materials 

due to their small lateral dimensions and to the greater ability of 

nanostructures to accommodate 

strain. Three examples illustrate 

the range of contacts that are possible with different nanomaterials. 

First, abrupt epitaxial silicide/silicon 

nanowire junctions with novel orientations can be formed at temperatures well below those required

for thin metal films, providing new 

opportunities for emerging devices 

such as metal source-drain 

MOSFETs and SpinFETs. Second, 

for metal contacts to carbon nanotubes, catalytically driven carbonization of the interface results in an 

electrically transparent grapheneResearchers from the CNST and 

Sandia National Laboratories have 

published a detailed review of recent experimental and theoretical 

work highlighting the unusual physics and material science of electrical 

contacts to nanostructures. In the 

Nature Nanotechnology article, the 

researchers explain that existing 

models of electrical contacts in bulk 

semiconductor devices are inapplicable at the nanoscale, and argue 

that in order for nanosystems to 

progress to practical use, it is critical to control charge at the electrical contacts. New models are required to understand contact formation and charge transport. In 

conventional contacts, the interface 

between a metal and a semiconductor is planar, but nanocontacts have 

multiple possible geometries, each 

CNT contact. Finally, making low 

resistance ohmic contacts to semiconductor nanowires has proven 

challenging and requires new understanding of doping at the nanometer scale. The researchers conclude that better understanding of 

the basic science of nanoscale contacts is necessary to allow 

nanoscale materials to be 

incorporated 

into useful new 

device designs. 

Electrical contacts 

to one- and twodimensional nanomaterials, F. Leonard and A. A. Talin, 

Nature Nanotechnology 6, 773-783 

(2011). An illustration of a single carbon nanotube 

encapsulated by an electrode.

Scanning electron micrograph of a silicon single electron device. Electrons are trapped in a quantum dot, 

defined by the field from two conducting gates. 

Existing models 

of electrical 

contacts in bulk 

semiconductor 

devices are 

inapplicable at 

the nanoscale. 

In order for 

nanosystems to 

progress to 

practical use, it 

is critical to 

control charge 

at the electrical 

contacts. 
P A G E 6

ongoing debate over the correct 

form of the electromagnetic momentum density in matter. In the 

“Minkowski formulation,” the momentum density is proportional to 

the index of refraction; in direct 

contrast, the “Abraham formulation” finds it to be inversely proportional. While light is known to 

carry mass, a detailed model for 

mass transfer from light to a medium that absorbs light had not been 

formulated to date. The researchers propose a set of postulates for 

light-matter interaction that encompass: a) the Maxwell equations, 

which govern classical electromagnetic behavior; b) a generalized 

Lorentz force law, which describes 

the force felt by matter in the presence of an electromagnetic field; c) 

a model for electromagnetic mass 

density transfer to an absorbing 

medium; and d) the Abraham formulation of momentum density. 

Using both closed-form calculations 

and numerical simulations of the 

Researchers from the CNST and 

the University of British Columbia 

have shown that the interaction 

between a light pulse and a lightabsorbing object, including the momentum transfer and resulting 

movement of the object, can be 

calculated for any positive index of 

refraction using a few, wellestablished physical principles combined with a new model for mass 

transfer from light to matter. This 

work creates a foundation for understanding light absorption in 

metamaterials, artificially tailored 

materials of intense interest in 

nanophotonics and microwave 

engineering that can have negative 

indices of refraction, and have potential applications in high resolution imaging, lithography, optical 

sensing, high gain antennas, and 

stealth radar coatings.

Light carries momentum and can 

transfer momentum to matter via 

radiation pressure. However, for 

the past century, there has been an 

interaction between an electromagnetic pulse and a test slab, the researchers demonstrated that their 

postulates yield results that are 

consistent with conservation of 

energy, mass, momentum, and center-of-mass velocity at all times. 

They further showed that satisfaction of the last two conservation 

laws unambiguously identifies the 

Abraham form as the true form of 

momentum density in a positiveindex medium. In addition to the 

theoretical significance of these 

results and the implications for 

metamaterials, the results will enable more accurate modeling of light

-matter interaction at the nanoscale 

and open new routes to optical 

control of nano-mechanical systems 

incorporating light absorbing materials.

Revisiting the Balazs thought experiment in 

the presence of loss: electromagnetic-pulseinduced displacement of a positive-index slab 

having arbitrary complex permittivity and 

permeability, K. J. Chau and H. J. Lezec, 

Applied Physics A 105, 267-281 (2011). 

Researchers from 

the CNST and Purdue University have 

designed and fabricated an on-chip 

microresonator that 

converts continuous 

laser light into ultrashort pulses consisting of a mix of welldefined frequencies, 

a technology with 

applications in advanced sensors, 

communications systems, and 

metrology. In the new approach, 

infrared light from a continuous 

laser enters a chip through a single 

optical fiber and is directed into an 

80 μm-diameter silicon nitride ring. 

The microscale ring acts as a nonlinear optical resonator with a defined set of resonances that reemit 

the light in a set of evenly spaced 

frequencies. These are called 

“comb lines” because they resemble 

teeth on a comb when represented 

on a frequency graph. The light is 

then collected through another 

optical fiber and sent to a pulse 

shaper to control the phase of each 

individual frequency line. The 

research team demonstrated that 

an optical frequency comb generated on-chip in this way can be highly 

coherent, meaning that individual 

comb lines remain synchronized 

with each other for long periods of 

time. Moreover, the phases of the 

comb lines can be adjusted to compress the light into a train of ultrashort pulses. The high repetition 

rate of the pulses produced by the 

on-chip microresonators may enable their use for improving the 

performance of high speed electron 

microscopes. In addition, they may 

be competitive with mode-locked 

lasers for some laboratory measurement applications: such lasers 

also produce a train of short pulses 

with well-defined frequencies, but 

are typically much larger than the 

chip-based devices and are limited 

by longer time delays between 

pulses.

Spectral line-by-line pulse shaping of on-chip 

microresonator frequency combs, F. Ferdous, 

H. Miao, D. E. Leaird, K. Srinivasan, J. Wang, 

L. Chen, L. T. Varghese, and A. M. Weiner, 

Nature Photonics 5, 770-776 (2011).

Microscope image 

of a 40 μm-radius 

microring with a 

coupling region. 

On-Chip Resonator Produces Ultra-Short Light Pulses

Researchers Resolve Century-Long Debate Over How to Describe 

Electromagnetic Momentum Density in Matter

The interaction 

between a light 

pulse and a lightabsorbing object 

can be calculated 

for any positive 

index of refraction 

using a few, wellestablished physical principles combined with a new 

model for mass 

transfer from light 

to matter.
S P R I N G 2 0 1 2

P A G E 7

NanoFab Develops Process for Fabricating Gratings for Optical Devices

direct-write e-beam lithography 

(EBL) to define the grating pattern, 

and reactive ion etching (RIE) to 

anistropically etch the pattern into 

the substrate material. By using 

direct write EBL, the engineers can 

tailor the spacing as well as the 

location of the gratings to produce 

diffracted light of any desired optical wavelength. Their fabricated 

gratings have linewidths and pitches 

ranging from 100 nm to 400 

nm. Unlike gratings produced using 

interferometry, which have crosssections which are sinusoidal, this 

technique produces gratings with 

rectangular cross-sections. Given 

the widespread 

use of optical 

gratings in a 

variety of devices, the engineers believe 

that this process 

will be a valuable nonproprietary tool for 

laser and optics 

manufacturers 

who want to 

incorporate 

optical gratings 

into their device designs.

New Staff in the NanoFab 

Kerry Siebein is a Process Engineer in the NanoFab. She received 

a B.S. in Mechanical Engineering 

from the Worcester Polytechnic 

Institute and a Ph.D. in Materials 

Science and Engineering from the 

University of Florida. Prior to 

joining the CNST, she managed the 

transmission electron microscopy 

and field emission scanning electron microscopy laboratories at 

the Major Analytical Instrumentation Center at the University of Florida, and taught, 

trained, and assisted students and faculty. Kerry is 

responsible for training NanoFab users and for operating the focused ion beam systems, scanning electron 

microscopes, and the transmission electron microscope in the NanoFab. 

James Bittner is an Engineering Technician in the 

NanoFab. He has a B.S. in Physics 

from Longwood University, and 

has extensive experience repairing 

and troubleshooting computercontrolled electrical and mechanical systems. In the NanoFab, 

James assists researchers, maintains laboratory equipment, and 

services several 

advanced tools. 

Joshua Schumacher is a Senior 

Process Engineer in the NanoFab. 

He received a B.S. and a Ph.D. in 

Electrical Engineering from the 

University of South Florida (USF), 

where he also received a certificate in Materials Science. Prior to 

joining the CNST, Joshua worked 

on materials characterization using 

scanning electron microscopy, 

transmission electron microscopy, 

and focused ion beam systems at 

the Nanotechnology Research and Education Center 

at USF. Joshua is responsible for training NanoFab 

users and for operating the NanoFab’s focused ion 

beam systems. 

Liya Yu is a Process Engineer in the NanoFab. She 

received a B.S. in Material Science from National 

Cheng Kung University, Taiwan, and a Ph.D. in Materials Science and Engineering from 

North Carolina State University. 

Prior to joining the CNST, she 

worked on process optimization 

for deep ultraviolet lithography at 

the North Carolina State University Nanofabrication Facility. Liya is 

responsible for developing and 

maintaining lithography processes 

in the NanoFab and for training 

and assisting users. 

Engineers in the CNST NanoFab 

have developed a set of techniques 

to manufacture optical gratings 

tailored to the needs of photonics, 

medical imaging, and telecommunications researchers. While optical 

gratings are typically manufactured 

using interferometric techniques 

that expose a large surface area, 

gratings produced using nanofabrication techniques can be localized 

anywhere on a wafer surface, allowing them to be integrated into the 

fabrication of a wide variety of devices, including lasers, spectrometers, and wavelength division multiplexing devices. The engineers use 

Scanning electron micrographs of a set of 

nanofabricated optical gratings. The grating 

widths and pitches can be varied to meet the 

800 nm
National Institute of Standards and Technology

100 Bureau Drive, MS 6200

Gaithersburg, MD 20899-6200

Phone: 301-975-8001

E-mail: cnst@nist.gov

The CNST is a national user facility purposely designed to 

accelerate innovation in nanotechnology-based commerce. 

Its mission is to operate a national, shared resource for nanoscale fabrication and measurement and develop innovative nanoscale measurement and fabrication capabilities to 

support researchers from industry, academia, NIST, and 

other government agencies in advancing nanoscale technology from discovery to production. The Center, located in

the Advanced Measurement Laboratory Complex on NIST’s 

Gaithersburg, MD campus, disseminates new nanoscale 

measurement methods by incorporating them into facility 

operations, collaborating and partnering with others, and 

providing international leadership in nanotechnology.

If you would like to subscribe to this newsletter, go to http://

www.nist.gov/cnst/newsletters.cfm, enter your e-mail address, and follow the on-screen instructions. 

Center for Nanoscale Science and 

Technology

www.nist.gov/cnst

Supporting the development of 

nanotechnology from discovery to production.

Disclaimer: Certain commercial equipment, and software, are identified in this documentation to describe the subject adequately. Such identification does not 

imply recommendation or endorsement by the National Institute of Standards and Technology, nor does it imply that the equipment identified is necessarily 

the best available for the purpose.

120524

Announcing the Next

NanoFab Users Meeting

Thursday, June 7, 2012, 2 pm to 4 pm

Building 215/C103

Current and potential NanoFab researchers and others 

interested in NanoFab operations are invited to the quarterly 

NanoFab Users meeting. Topics typically include safety, policy 

changes, new equipment purchases or upgrades, research 

highlights, and new standard processes. Every meeting also 

includes an open discussion to allow users to bring ideas and 

suggestions to our attention. Anyone wishing to have a 

specific item added to the agenda should contact Vincent 

Luciani at 301-975-2886, vincent.luciani@nist.gov.

The new Avenger Spray Solvent System heated metal liftoff tool will be delivered in June. The device 

will provide automatic recipe control and reduce liftoff time from hours to minutes. It will process 

samples ranging from 150 mm-diameter wafers down to 25 mm-on-a-side squares. For more 

information, contact Jerry Bowser at 301-975-8187, jerry.bowser@nist.gov.

NanoFab Purchases Automated Lift-Off Tool

Visit the CNST Booth 

at the 

TechConnect World Summit and 

Innovation Showcase, 

Santa Clara, CA

June 18—21, 2012