# Presentation: 834741

## Nanotechnology R&D at NIST

- Robert Celotta, Director
- The Center for Nanoscale Science and Technology
- NIST – TEDCO Showcase
- April 8, 2008

**(For further information see: http://cnst.nist.gov)**

## Outline	 

- NIST at a Glance
- The New Center for Nanoscale Science and Technology
- The Nanofab
- The Research Program
- Quick Tour of Nanotechnology throughout NIST

## The NIST Laboratories

## CNST Mission and Structure

- Mission:
- To enable the development of nanotechnology
- Provides both research and access to facilities
- Works to solve outstanding nanoscale measurement and fabrication problems
- Structure:
- The CNST consists of a Research Program and the CNST Nanofab
- The Nanofab
- A national facility offering convenient and economical access to expensive nanoscale measurement and fabrication tools.
- The Research Program
- Multidisciplinary research staff operates in a highly collaborative mode

## Advanced Measurement Laboratory

- CNST leverages the facilities of the AML – arguably the world’s most advanced laboratory – for its nanotechnology research.

## The CNST Nanofab is well equipped and expandingSee cnst.nist.gov for details

**Notes:**
We have ...
  Specialty Tools
Focused Ion Beam: Zeiss NVision 40 
Nano-Imprint Lithography Tool: Nanonex NX-2000 
E-beam Lithography System: Leica VB300 
Microwave Asher 
Focused Ion Beam: FEI Nova 600 Nanolab
  Lithography
E-beam Lithography System: Leica VB300 
Modified SEM E-beam Lithography: JEOL 6400 
Nano-Imprint Lithography Tool: Nanonex NX-2000 
MA6 Front and Back Contact Aligner: Suss Microtec 
MA8 Front Side Contact Aligner: Suss Microtec 
Spinners: Laurell Technologies Series WS-400/500 
Spinner: Brewer Science CEE Model 100CB Spinner/Hotplate
  Post Process
Microwave Asher 
Focused Ion Beam: Zeiss NVision 40
Wafer Dicing Saw-Disco Model 341
Wire Bonder: Kulicke and Soffa Model 4526
Critical Point Dryer
Focused Ion Beam: FEI Nova 600 Nanolab
  Furnaces
General Thermal Oxidation and Diffusion Furnace/Bank 2 
CMOS Thermal Oxidation and Diffusion Furnace/Bank 1 
Low Pressure Chemical Vapor Deposition (LPCVD) Furnace/Bank 3 
Rapid Thermal Annealer-Modular Process Technology 
PECVD-Unaxis 790
    Dry Etch
Deep RIE-Unaxis SHUTTLELINE DSEII 
Metal RIE-Unaxis 790 
Silicon RIE-Unaxis 790 
ICP Metal Etcher-Unaxis SHUTTLELINE ICP 
XeF2 Silicon Etch-Xactix Xetch e1 Series 
Microwave Asher
  Metal Deposition
E-beam Evaporator: Denton Infinity 22 
Thermal Evaporator: Denton Infinity 22 
Sputterer: Denton Discovery 22 
CVC Evaporator 
Myers Evaporator
  Wet Chemistry
Heated Wet Chemical Bench: 6-ft 
Heated Wet Chemical Bench: 8-ft 
Spin Rinse Dryers: Semitool PSC-101
  Inspection
Scanning Electron Microscope: Zeiss Ultra-60 FESEM 
Spectroscopic Ellipsometer: Woollam XLS-100 
Nanospec Reflectometer: Nanometrics 
Contact Profilometer: Dektak 6M 
Optical Microscope with Image Capture: Nikon 
Four-Point Probes (two units): Jandel RM2
Are adding...
Wafer bonder
Second sputterer
Laser writter
Afm
Plasma etcher for III-V
Kerr microscopy
ALD?

## Research Program

- Developing measurement capabilities for:
**Future Electronics**
- Devices, architectures, interconnects
**Nanomanufacturing and Nanofabrication**
- Top-down and bottom-up fabrication and assembly
**Energy**
- Conversion, storage, and transport
- Complementary to and interactive with strong, existing NIST Laboratory programs
- Areas of concentration will, of necessity, change with needs

## Core Competences

**Atomic Scale Characterization and Manipulation**
- Fabrication and measure the geometric and electronic structure of materials with atomic resolution using a UHV cryogenic/high magnetic field scanning tunneling microscope system.
**Directed Assembly**
- Fabrication and study the effects of templating structures on the organization of nanoscale materials and their resultant properties.
**Laser-Atom Manipulation**
- Laser control of atomic motion is used to develop new nanofabrication and nanoscale measurement methods.
**Nanomagnetic Imaging (SEMPA)**
- Use of spin polarized electrons generated in a scanning electron microscope to image magnetic structures over a large magnification range. Measurements are sensitive to less than a monolayer of magnetic material.
**Nanophotonics**
- Study of nanofabricated optical structures that confine light to wavelength-scale dimensions and to investigate light-matter interactions with near-field probing and microphotoluminescence setups.
**Nanoscale Transport **
- Device fabrication and photo-electrical probing of electronic and ionic transport properties of thin-film materials and nanoscale objects equipped with probe station, cryostats, air/ liquid /high-vacuum STM/cAFM.
**Nanoplasmonics **
- Design and nanofabrication of metal-based photonic components and metamaterials which exploit subwavelength confinement of light, for applications in information processing, metrology, and microscopy.
**Nanomagnet Dynamics**** **
- Fabrication and measurement of magnetization dynamics of magnetic nanostructures.  Microwave spectroscopy techniques yield precise information on material and structure properties at the nanoscale
**	****NEMs, MEMs, Nanoscale Process Control (Coming soon) +**

## Highlights:

Molecular Spintronics
Used nanoscale pore in Si wafer
One molecule thick layer of self assembled molecules
Observed vibrational energies of molecular states
Laser-based Nanotube Cleanup
Purifies raw nanotube material
Reduces carbon impurities, e.g., graphite, soot, etc.
Does not destroy tubes 
Nanoscale Pores Provide Analysis
Detects and sorts different sized polymer chains
Uses a lipid bilayer membrane
Pore size ~ 1.5 nm
Current flow indicates chain size

***Molecular Spintronics***
***Used nanoscale pore in Si wafer***
***One molecule thick layer of self assembled molecules***
***Observed vibrational energies of molecular states***
***Laser-based Nanotube Cleanup***
***Purifies raw nanotube material***
***Reduces carbon impurities, e.g., graphite, soot, etc.***
***Does not destroy tubes****** ***
***Nanoscale Pores Provide Analysis***
***Detects and sorts different sized polymer chains***
***Uses a lipid bilayer membrane***
***Pore size ~ 1.5 nm***
***Current flow indicates chain size***

## Highlights:

Nanotechnology Research Recognized with two    Nano 50 Awards
Scanning Electron Microscopy
Scatterfield Optical Microscopy
First Results Reported for Helium Ion Microscopy
New instrument has been installed
Study of imaging process has begun

***Nanotechnology Research Recognized with two    Nano 50 Awards***
***Scanning Electron Microscopy***
***Scatterfield Optical Microscopy***
***First Results Reported for Helium Ion Microscopy***
***New instrument has been installed***
***Study of imaging process has begun***

## Highlights:

Nanowire Device Fabrication Method Demonstrated
Nanowires grown on sapphire wafer in specific locations and directions
Gold deposits used as nucleation points
Zinc Oxide nanowires grown to create 600 nanowire based transistors
Nanoelectronic Switch Demonstrated
Uses self-assembled layers of organic molecules
Silver atoms quickly assemble to form conduction path
Growth provides nanoscale binary switch
SWNT Interaction with Polarized Light Studied
DNA stretching alignment method used
First experimental verification of optical response
Joint with Physics Lab and RIT

***Nanowire Device Fabrication Method Demonstrated***
***Nanowires grown on sapphire wafer in specific locations and directions***
***Gold deposits used as nucleation points***
***Zinc Oxide nanowires grown to create 600 nanowire based transistors***
***Nanoelectronic Switch Demonstrated***
***Uses self-assembled layers of organic molecules***
***Silver atoms quickly assemble to form conduction path***
***Growth provides nanoscale binary switch***
***SWNT Interaction with Polarized Light Studied***
***DNA stretching alignment method used***
***First experimental verification of optical response***
***Joint with Physics Lab and RIT***

**Notes:**
NIST Demos Industrial-Grade Nanowire Device Fabrication (25 Oct 2007)

Nanowire electronics: (Top) Optical image shows metal electrodes attached to zinc oxide nanowires using the NIST technique. Dark spots near the center are the gold pads that start nanowire growth; red arrow shows direction of growth. Scale bar is 50 micrometers long. (Bottom) Scanning electron microscope image shows electrodes connected to group of nanowires. Scale bar is five micrometers long.
Credit: NISTView hi-resolution image (top)View hi-resolution image (bottom)
In the growing catalog of nanoscale technologies, nanowires—tiny rows of conductor or semiconductor atoms—have attracted a great deal of interest for their potential to build unique atomic-scale electronics. But before you can buy some at your local Nano Depot, manufacturers will need efficient, reliable methods to build them in quantity. Researchers at the National Institute of Standards and Technology (NIST) believe they have one solution—a technique that allows them to selectively grow nanowires on sapphire wafers in specific positions and orientations accurately enough to attach contacts and layer other circuit elements, all with conventional lithography techniques. They detailed their results in a recent paper.*
Despite their name, nanowires are more than just electrical connectors. Researchers have used nanowires to create transistors like those used in memory devices and prototype sensors for gases or biomolecules. However working with objects only tens of nanometers wide is challenging. A common approach in the lab is to grow nanowires like blades of grass on a suitable substrate, mow them off and mix them in a fluid to transfer them to a test surface, using some method to give them a preferred orientation. When the carrier fluid dries, the nanowires are left behind like tumbled jackstraws. Using scanning probe microscopy or similar tools, researchers hunt around for a convenient, isolated nanowire to work on, or place electrical contacts without knowing the exact positions of the nanowires. It’s not a technique suitable for mass production.
Building on earlier work to grow nanowires horizontally on the surface of wafers (see “Gold Nano Anchors Put Nanowires in Their Place”), NIST researchers used conventional semiconductor manufacturing techniques to deposit small amounts of gold in precise locations on a sapphire wafer. In a high-temperature process, the gold deposits bead up into nanodroplets that act as nucleation points for crystals of zinc oxide, a semiconductor. A slight mismatch in the crystal structures of zinc oxide and sapphire induces the semiconductor to grow as a narrow nanowire in one particular direction across the wafer. Because the starting points and the growth direction are both well known, it is relatively straightforward to add electrical contacts and other features with additional lithography steps.
As proof of concept, the NIST researchers have used this procedure to create more than 600 nanowire-based transistors, a circuit element commonly used in digital memory chips, in a single process. In the prototype process, they report, the nanowires typical grew in small bunches of up to eight wires at a time, but finer control over the size of the initial gold deposits should make it possible to select the number of wires in each position. The technique, they say, should allow industrial-scale production of nanowire-based devices.
For more examples of NIST research on nanowire electronics, see: “New Design Developed for Silicon Nanowire Transistors,” “Growing Glowing Nanowires to Light Up the Nanoworld,” “New Fabrication Technique Yields Nanoscale UV LEDs,” “Placing Single Nanowires: NIST Makes the Connection,” and “Silicon Nanowires Upgrade Data-Storage Technology.”
B. Nikoobakht. Toward industrial-scale fabrication of nanowire-based devices. Chem. Mater., ASAP Article 10.1021/cm071798p S0897-4756(07)01798-X. Web Release Date: October 9, 2007.
=======================
Frozen Lightning: NIST’s New Nanoelectronic Switch (1 Mar 2007) 
Silver nanoswitch: When the voltage between a gold conductor (top) and silver conductor (bottom) exceeds a critical point, silver ions rapidly assemble like a lightning strike to bridge the gap through a organic molecule monolayer.
Credit: NISTView hi-resolution image
Researchers at the National Institute of Standards and Technology (NIST) have demonstrated a prototype nanoscale electronic switch that works like lightning—except for the speed. Their proof-of-concept experiments reported last week* demonstrate that nanoscale electrical switches can be built from self-assembled layers of organic molecules on silver wires. Potential applications range from a replacement technology for magnetic data storage to integrated circuit memory devices.
Silver would be a natural choice for nanoscale and microscale electrical contacts because of its high conductivity, but it has one notorious drawback. In an electric field, silver ions readily form silver “whiskers,” tree-like branching growths of crystals that can short-out microelectronic devices.
Two NIST researchers have demonstrated that this can be a feature, not a bug, in an elegant experiment that uses this growth to make a nanoscale binary switch. In the experiment, an extremely fine silver wire is coated with a molecule that forms a self-assembled monolayer on the wire, typically some organic molecule with a sulfur group on one end to bond to the silver. An equally fine gold wire is laid crosswise to the silver wire and a small voltage is applied across the two wires. When the voltage is increased to a critical level, silver ions form and quickly branch through the organic monolayer to the gold wire just like a lightning bolt—except solid. When a silver filament reaches the gold, it forms a short circuit, causing a dramatic change in conductance, which is easily detectable. Reversing the voltage retracts the filament and “opens” the switch. 
NIST chemist James Kushmerick adjusts test apparatus demonstrating a prototype silver nanoswitch.
Credit: NISTView hi-resolution image
As a candidate logic switch for nanoscale memory circuits and similar devices, the silver whisker switch has several attractive features:
The chemistry of the organic monolayer is not critical; the switch works with many different molecules and so can be used with many different self-assembled molecular electronics systems. 
The crossed-wire structure is very simple to engineer and lends itself to large arrays of switches. 
The difference between “on” and “off” is huge—electrical resistance ratios of a million or more. This makes it easier to reliably scale up the technology to very large arrays. 
Problems to be overcome, according to the researchers, include volatility—the voltage has to be kept on to retain the switch state; slow switching speeds—about 10 kilohertz in the prototype; and a tendency of the switch to freeze permanently closed after a large number of cycles.
NIST has applied for a patent on the switch.
*J.M. Beebe and J.G. Kushmerick. Nanoscale switch elements from self-assembled monolayers on silver. Applied Physics Letters 90, 083117 (2007). Posted online Feb. 23, 2007.
===================================================================

NIST’s Stretching Exercises Shed New Light on Nanotubes (12 Apr 2007)

Biomedical applications could exploit the natural fluorescence of the carbon nanotubes. When light is polarized along a single-walled carbon nanotube (left), this fluorescent emission is strong. For perpendicular polarization (right), however, the emission disappears.
Credit: NISTView hi-resolution image
Stretching a carbon nanotube composite like taffy, researchers at the National Institute of Standards and Technology (NIST) and the Rochester Institute of Technology (RIT) have made some of the first measurements* of how single-walled carbon nanotubes (SWNTs) both scatter and absorb polarized light, a key optical and electronic property.
SWNTs have excited materials scientists with the promise of novel materials that have exceptional mechanical, electronic, and optical properties. One fundamental issue is how light interacts with SWNTs. Is there, for example, a way to use appropriately tailored light to exert a force on SWNTs so that they can be trapped or aligned? Or can they be designed to be nanoscale tags for medical diagnostics? Semiconducting SWNTs can fluoresce in the near infrared region, an ideal characteristic for medical applications because body fluids and tissues are nearly transparent in that range.
Recent research on the optics of SWNTs has focused on the behavior of “excitons” — the pairing of a negatively charged electron with the positively charged “hole” that it leaves behind when it gets excited by a photon into a higher energy state. An important optical characteristic is how excitons in SWNTs impact the way the nanotubes absorb and scatter light.For example, how easy is it for the incident light to deform an exciton to create positive and negative poles? Theory says it should be significantly harder to do in a nearly one-dimensional nanotube than in a bulk semiconductor, where nearby electrons and holes reduce the amount of energy required.
Measuring that is difficult because the effect depends on the orientation of the nanotubes, and they’re hard to line up neatly. The NIST/RIT team solved the problem elegantly by wrapping SWNTs with DNA to keep them from clumping together, and dispersing them in a polymer. When they heated the polymer and stretched it in one direction, the nanotubes aligned like sugar crystals lining up in pulled taffy, making the optical measurements possible. The team obtained the first experimental verification of the full optical response of individual semiconducting SWNTs, finding good agreement with theory.
The stretching alignment technique is applicable to a broad range of SWNT experiments where orientation is important, particularly in optics. The work should further our current understanding of how nanotubes interact with light, with important practical applications in optical sensing and the manipulation of individual nanotubes using electromagnetic fields.
* J.A. Fagan, J.R. Simpson, B.J. Landi, L.J. Richter, I.Mandelbaum, V. Bajpai, D.L. Ho, R. Raffaelle, A.R. Hight Walker, B.J. Bauer and E.K. Hobbie. Dielectric response of aligned semiconducting single-wall nanotubes. Physical Review Letters. 98, 147402 (2007).
Media Contact: Michael Baum, michael.baum@nist.gov, (301) 975-2763

## Highlights:

New Hybrid Microscope Developed
Scanning Photoionization Microscopy (SPIM)
High spatial resolution 
Electrical sensitivity from low energy electron detection

Highly Charged Ions Used to Study GMR/TMR
Insulating buffer layer modified by xenon +44 ions
Device incorporates both GMR and TMR effects

High Speed Nanoscale Vibrations Measured
The 40 MHz NEM vibrations observed
Offers potential of 500-fold increase in STM speed

***New Hybrid Microscope Developed***
***Scanning Photoionization Microscopy (SPIM)***
***High spatial resolution ***
***Electrical sensitivity from low energy electron detection***
***Highly Charged Ions Used to Study GMR/TMR***
***Insulating buffer layer modified by xenon +44 ions***
***Device incorporates both GMR and TMR effects***
***High Speed Nanoscale Vibrations Measured***
***The 40 MHz NEM vibrations observed***
***Offers potential of 500-fold increase in STM speed***

**Notes:**
New Hybrid Microscope Probes Nano-Electronics (26 Oct 2006)

JILA's scanning photoionization microscope (SPIM) includes an optical microscope (in vacuum chamber, background) and an ultrafast laser (appears as blue, foreground). A false color SPIM image (b) reveals the same physical structure of a gold pattern on glass as an atomic force microscope image (a), but the high intensity regions in the SPIM image indicate that electron ejection is much more efficient at metal edge discontinuities.
Credit: O.L.A. Monti, T.A. Baker, and D.J. Nesbitt/JILA
View larger image of scanning photoionization microscope
View larger image of SPIM image 
A new form of scanning microscopy that simultaneously reveals physical and electronic profiles of metal nanostructures has been demonstrated at JILA, a joint institute of the National Institute of Standards and Technology (NIST) and University of Colorado at Boulder. The new instrument is expected to be particularly useful for analyzing the make-up and properties of nanoscale electronics and nanoparticles.
Scanning photoionization microscopy (SPIM), described in a new paper,* combines the high spatial resolution of optical microscopy with the high sensitivity to subtle electrical activity made possible by detecting the low-energy electrons emitted by a material as it is illuminated with laser pulses. The technique potentially could be used to make pictures of both electronic and physical patterns in devices such as nanostructured transistors or electrode sensors, or to identify chemicals or even elements in such structures.
“You make images by virtue of how readily electrons are photoejected from a material,” says NIST Fellow David Nesbitt, leader of the research group. “The method is in its infancy, but nevertheless it really does have the power to provide a new set of eyes for looking at nanostructured metals and semiconductors.”
The JILA-built apparatus includes a moving optical microscopy stage in a vacuum, an ultrafast near-ultraviolet laser beam that provides sufficient peak power to inject two photons (particles of light) into a metal at virtually the same time, and equipment for measuring the numbers and energy of electrons ejected from the material. By comparing SPIM images of nanostructured gold films to scans using atomic force microscopy, which profiles surface topology, the researchers confirmed the correlations and physical mapping accuracy of the new technique. They also determined that lines in SPIM images correspond to spikes in electron energy, or current, and that contrast depends on the depth of electrons escaping from the metal as well as variations in material thickness.
Work is continuing to further develop the method, which may be able to make chemically specific images, for example, if the lasers are tuned to different colors to affect only one type of molecule at a time. The research is supported by the Air Force Office of Scientific Research and National Science Foundation.
* O.L.A. Monti, T.A. Baker and D.J. Nesbitt. 2006. Imaging nanostructures with scanning photoionization microscopy. Journal of Chemical Physics, October 21.
===========================================================
Nanoscale Blasting Adjusts Resistance in Magnetic Sensors (16 Aug 2007)

Cartoon illustrates new NIST technique for selectively modifying resistance of a semiconductor device layer. (Top) First layer—in this case a composite of copper and cobalt—and an insulating buffer layer of aluminum oxide is deposited. Buffer is about one nanometer thick. (Middle) Highly charged xenon +44 ions strike the buffer layer, digging nanoscale pits. (Bottom) Top conducting layer of cobalt and copper is deposited. Pits reduce the electrical resistance of the layers and may function as nanoscale GMR sensors embedded in a MTJ sensor.
Credit: NISTView hi-resolution image
A new process for adjusting the resistance of semiconductor devices by carpeting a small area of the device with tiny pits, like a yard dug up by demented terriers, may be the key to a new class of magnetic sensors, enabling new, ultra-dense data storage devices. The technique demonstrated by researchers at the National Institute of Standards and Technology (NIST)* allows engineers to tailor the electrical resistance of individual layers in a device without changing any other part of the processing or design.
The tiny magnetic sensors in modern disk drives are a sandwich of two magnetic layers separated by a thin buffer layer. The layer closest to the disk surface is designed to switch its magnetic polarity quickly in response to the direction of the magnetic “bit” recorded on the disk under it. The sensor works by measuring the electrical resistance across the magnetic layers, which changes depending on whether the two layers have matching polarities.
As manufacturers strive to make disk storage devices smaller and more densely packed with data, the sensors need to shrink as well, but current designs are starting to hit the wall. To meet the size constraints, prototype sensors measure sensor resistance perpendicular to the thin layers, but depending on the buffer material in the sensor, two different types of sensors can be made. Giant magneto-resistance (GMR) sensors use a low-resistance metal buffer layer and are fast, but plagued by very low, difficult to detect, signals. On the other hand, magnetic tunnel junction (MTJ) sensors use a relatively high-resistance insulating buffer that delivers a strong signal, but has a slower response time, too slow to keep up with a very high-speed, high-capacity drive.
What’s needed, says NIST physicist Josh Pomeroy, is a compromise. “Our approach is to combine these at the nanometer scale. We start out with a magnetic tunnel junction—an insulating buffer—and then, by using highly charged ions, sort of blow out little craters in the buffer layer so that when we grow the rest of the sensor on top, these craters will act like little GMR sensors, while the rest will act like an MTJ sensor.” The combined signal of the two effects, the researchers argue, should be superior to either alone.
The NIST team has demonstrated the first step—the controlled pockmarking of an insulating layer in a multi-layer structure to adjust its total resistance. The team uses small numbers of highly charged xenon ions that each have enormous potential energies—and can blast out surface pits without damaging the substrate. With each ion carrying more than 50 thousand electron volts of potential energy, only one impact is needed to create a pit—multiple hits in the same location are not necessary. Controlling the number of ions provides fine control over the number of pits etched, and hence the resistance of the layer—currently demonstrated over a range of three orders of magnitude. NIST researchers now are working to incorporate these modified layers into working magnetic sensors.
The new technique alters only a single step in the fabrication process—an important consideration for future scale-up—and can be applied to any device where it’s desirable to fine-tune the resistance of individual layers. NIST has a provisional patent on the work, number 60,905,125.
* J.M. Pomeroy, H. Grube, A.C. Perrella and J.D. Gillaspy. Selectable resistance-area product by dilute highly charged ion irradiation. Appl. Phys. Lett. 91, 073506 (2007).
===============================================================
New JILA Apparatus Measures Fast Nanoscale Motions (16 Mar 2007)

This slow-motion simulation of the JILA nanoscale motion detector shows the wiggling of a floppy metal beam, just 100 nanometers thick, as it is struck by an electric current at the dot. Red indicates the greatest change in position from the rest state.
Credit: K. Lehnert/JILAView hi-resolution image
View .avi movie 
A new nanoscale apparatus developed at JILA—a tiny gold beam whose 40 million vibrations per second are measured by hopping electrons—offers the potential for a 500-fold increase in the speed of scanning tunneling microscopes (STM), perhaps paving the way for scientists to watch atoms vibrate in high definition in real time.
The new device measures the wiggling of the beam, or, more precisely, the space between it and an electrically conducting point just a single atom wide, based on the speed of electrons “tunneling” across the gap. The work is the first use of an “atomic point contact,” the business end of an STM, to sense a nanomechanical device oscillating at its “resonant” frequency, where it naturally vibrates like a tuning fork. JILA is a joint venture of the National Institute of Standards and Technology (NIST) and the University of Colorado at Boulder.
Although the JILA technique, described in the March 2 issue of Physical Review Letters,* is not necessarily as precise as more complex and much colder methods of measuring very fast motions of ultra-small devices, it incorporates several innovative attributes. These include the ability to minimize unwanted random electronic “noise” as well as to measure the random shaking of the beam caused by back-action or recoil (similar to what happens when a gun is fired). This level of sensitivity is possible because the atomic point contact acts as an amplifier for these otherwise imperceptible factors, and the gold beam is tiny and floppy enough—just 100 nanometers (nm) thick, and 5.6 micrometers long by 220 nm wide—to respond to single electrons.
The new method involves bringing the sharp point within one nanometer of the gold beam. A current is applied through the point across the gap, until an increase in resistance indicates that electrons are “tunneling” across the gap (a phenomenon observed only at atomic dimensions). The size of the gap is then monitored based on variations in the current. The beam’s undulations were measured with tens to hundreds of times greater precision than a typical STM result. That’s because the oscillations are measured using microwave electronics, which are much faster than the audio frequency technology typically used with STMs, thus enabling greater precision. The microwave measurement technique could potentially be applied to STMs. 
The work was supported in part by NIST and the National Science Foundation. 
* N.E. Flowers-Jacobs, D.R. Smith and K.W. Lehnert. Intrinsic noise properties of atomic point contact displacement detectors. Physical Review Letters. 98, 096804 (2007).

## Highlights:

“Fossilized Liquid Assembly”
Components self assemble freely in liquid
UV light exposure polymerizes a monomer
Allows the study of the self assembly process
Carbon Nanotube Tools
Carbon “nanoknife” stretched between two tungsten needles
Could be applied to slice individual cells
Rapid Method for Judging Nanotube Purity
Uses simple quartz crystal apparatus
Resonance frequency change on heating
Gauges consistency of samples

***“******Fossilized Liquid Assembly”***
***Components self assemble freely in liquid***
***UV light exposure polymerizes a monomer***
***Allows the study of the self assembly process***
***Carbon Nanotube Tools***
***Carbon “nanoknife” stretched between two tungsten needles***
***Could be applied to slice individual cells***
***Rapid Method for Judging Nanotube Purity***
***Uses simple quartz crystal apparatus***
***Resonance frequency change on heating***
***Gauges consistency of samples***

## Nanotechnology R&D at NIST

- Robert Celotta, Director
- The Center for Nanoscale Science and Technology
- NIST – TEDCO Showcase
- April 8, 2008

**(For further information see: http://cnst.nist.gov)**

## Using the CNST Nanofab

- The Nanofab is a nanofabrication and nanoscale measurement facility
- Based on highly successful NNIN Nanocenter model
- Fee based, shared use
- Open to all users
- NIST site access restrictions apply
- Fees are based on operating costs
- Similar to the full cost recovery fees of the NNIN-NSF Nanocenters
- External users may apply to have a portion of their fee waived
- For research supportive of CNST goals
- Net charges similar to NNIN-NSF “academic” rates
- The Nanofab will train users in tool use
- Alternatively, the process can performed by a process engineer at an additional cost
- User can maintain IP rights under certain circumstances
- For information about use of the Nanofab
- Contact Dr. Alex Liddle (alex.liddle@nist.gov),