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CNST Group Seminars - 2007

 



BIOMIMETIC NANOSCIENCE: CHALLENGES AND OPPORTUNITIES


Prof. Joanna Aizenberg
Harvard University.

Tuesday, December 18, 2007, 10:30AM, Rm. C103-C106, Bldg. 215.

 

The adaptive pressures displayed across the flora and fauna result in a variety of sophisticated nanostructured materials that are perfected to perform multiple biological functions. Our understanding of the underlying principles of their formation provides ample opportunities in the synthesis of next generation, bio-inspired, nanostructured materials. To date, there has been demonstrable progress in materials fabrication harnessing the functional power of biological systems. There is, however, a number of challenges related to the characterization of both biological and synthetic bio-related structures. I will exemplify this point by describing new synthetic strategies and devices that have been inspired by the study of two organisms – echinoderms and sponges. The topics will include self-assembly, control of crystallization, adaptive optical structures, fiber-optics, biomechanics, hybrid materials and novel actuation systems.

 

For further information contact Nikolai Zhitenev, 301-975-6039, nikolai.zhitenev@nist.gov



NANOFAB USERS INFORMATION MEETING: BASELINE PROCESSES FOR TOOL BENCHMARKING


Marc Cangemi
CNST Nanofab Process Engineer.

Thursday, December 13, 2007, 1:30PM, Rm. H107, Bldg. 217.

 

In order to ensure the stability and reproducibility of the process tools of the Nanofab, a set of standard processes have been developed for most tools. These processes are run at regular intervals and a relevant parameter is measured to generate statistical process control charts. The methodology used and the current baseline data will be described.

 For further information contact Gerard Henein, 301-975-5645, gerard.henein@nist.gov


 

Surface Science Lunch Bunch

THE 2007 NOBEL PRIZES IN PHYSICS AND CHEMISTRY

 
Mark Stiles
NIST Center for Nanoscale Science and Technology.
Bill Gadzuk
NIST Electron and Optical Physics Division

Monday, December 10, 2007, 12:00PM, Rm. C301, Radiation Physics Bldg.

 

The 2007 Nobel Prizes in Physics and Chemistry recognize work that has a number of connections with NIST, mostly associated with attendees of the Surface Science Lunch Bunch. This homecoming reunion of the Bunch features talks by Mark Stiles (Center for Nanoscale Science and Technology) and Bill Gadzuk (Electron and Optical Physics Division) on the Physics and Chemistry Prizes, respectively. As always, at the Surface Science Lunch Bunch, you are welcome to eat your fill of all the food you bring yourself!

For further information contact Charles Clark, 301-975-3709, charles.clark@nist.gov 

COUPLING NANOMECHANICAL MOTION TO ELECTROMAGNETIC FIELDS THROUGH THE CASIMIR EFFECT AND SURFACE EVANESCENT WAVES


Dr. Ho Bun Chan
Department of Physics, University of Florida.

Friday, December 7, 2007, 2:00PM, Rm. C103-C106, Bldg. 215.

 

The miniaturization of mechanical devices opens new opportunities for investigating and exploiting novel phenomena that occur for components in close proximity. The Casimir force, for example, originates from the zero-point quantum fluctuations of the electromagnetic fields. I will describe experiments that demonstrated the Casimir effect in micromechanical devices. In another effort, subwavelength structures are fabricated on the surface of metal films to strongly modify their interaction with light. The evanescent fields channel the optical energy to specific locations, resulting in strong and localized field enhancement. Coupling of the enhanced evanescent field to the nanomechanical motion of the metallic elements opens new opportunities for tunable optical elements and high sensitivity displacement detection.

 
For further information contact Nikolai Zhitenev, 301-975-6039, nikolai.zhitenev@nist.gov

 

RESISTIVE SWITCHING FOR NEXT GENERATION FLASH MEMORY TECHNOLOGY


Christie R.K Marrian
Advanced Memory Group. Sunnyvale, CA

Monday, December 3, 2007, 1:30PM, Rm. H107, Bldg. 217.

 

Flash memory has been scaled remarkably successfully over the past decades and is now one of the main drivers of Moore's Law. However, the underlying physics of the memory cell is such that scaling is becoming increasingly difficult. As a result a number of alternative non-volatile technologies are being pursued to allow continued scaling of Flash memory. At Spansion we have focused on a two terminal metal-insulator-metal cell that exhibits two resistance states. The structure is compatible with microelectronics processing and has been fabricated in the BEOL of a CMOS type process flow. However, even this rather simple cell leads to a number of new thin film processing and metrology challenges.

 

For further information contact J. Alexander Liddle, 301-975-6050, james.liddle@nist.gov

 

VIBRONIC EFFECTS IN SUPERCONDUCTING NANOWIRES AND MOLECULAR CONTACTS


Prof. Alexei Marchenkov
School of Physics, Georgia Institute of Technology.

Monday, November 26, 2007, 10:30AM, Rm. C103-C106, Bldg. 215.

The generation of high-frequency current oscillations when a constant voltage is applied across an insulating tunnel gap separating two superconductors was one of the celebrated predictions made by B. Josephson in 1962. I will present evidence that Josephson current oscillations interact with atomic-scale mechanical motion. We generated weak links that contain a single niobium dimer (Nb2) suspended between two bulk niobium electrodes. We found spectral features in the electronic transport curves through the dimer, which correspond to excitations of its vibrational eigenmodes by Josephson current oscillations. This phenomenon persists up to the frequency of about 10 terahertz. This is applications-rich but largely unexplored frequency range ("terahertz gap"), which interrogates the lowest frequency vibrational modes of complex organic and biological molecules. I will describe possible applications in the fields of chemical and biological material sensing and characterization.

 

For further information contact Nikolai Zhitenev, 301-975-6039, nikolai.zhitenev@nist.gov

 

ELECTRICAL TRANSPORT PROPERTIES OF CARBON NANOTUBE THIN FILMS AND CRITICAL BEHAVIOR OF SUPERCONDUCTORS


Dr. Hua Xu
Center for Nanophysics and Advanced Materials, Department of Physics.

Wednesday, November 21, 2007, 1:30PM, Rm. H107, Bldg. 217.

With our developed broadband microwave measurement (DC to 50GHz) and high precision DC nonlinearity measurement systems, we have investigated the electrical transport properties of single walled carbon nanotube networks and superconducting phase transition of YBaCuO. Our results showed that SWCNT films are promising as a type of optical transparent microwave shielding material. We also studied temperature, frequency, and electric field dependent transport properties of SWCNT films of various thicknesses. A correlation between the frequency dependence and the electric field dependence of conductivity has been observed. The fluctuation effects of superconducting to normal phase transition of high-Tc materials YBaCuO have been discussed as well. Our results give the dynamical scaling exponent z= 1.55±0.15, which indicates the superconducting to normal phase transition of high-Tc materials belongs to the model E-dynamics.

 

For further information contact Nikolai Zhitenev, 301-975-6039, nikolai.zhitenev@nist.gov

 

TOWARD THE QUANTUM MANIPULATION OF DIPOLAR GASES

 


Benjamin Lev
University of Illinois, Urbana-Champaign.

Tuesday, November 20, 2007, 10:30AM, Rm. H107, Bldg. 217.

At the frontier of AMO physics is the possibility to create and control ultracold dipolar gases consisting of trapped polar molecules or highly magnetic atoms. The strong, long-range and anisotropic dipole-dipole interaction adds an entirely new feature to ultracold physics, and may be harnessed to explore collective and collisional phenomena that emerge when the dipole-dipole interaction dominates kinetic energy. From the perspective of quantum information processing and spin lattice simulations, this interaction is ideal for constructing the nearest-neighbor interactions crucial for realizing robust and scaleable experimental architectures. Moreover, large permanent dipoles provide strong interactions with external fields, dramatically increasing the ability to explore quantum phenomena using techniques co-opted from atom optics and cavity QED. We will present recent progress in the production and trapping of the polar molecule OH and address the feasibility of creating ultracold samples of ground state polar molecules using cavity-assisted laser cooling. In addition, the trapping and manipulation of strongly magnetic atoms using atom chips will be discussed.

For further information contact Andrew Berglund, 301-975-2844, andrew.berglund@nist.gov 

RESOLUTION, LER AND SENSITIVITY LIMITATIONS OF PHOTORESISTS


Gregg Gallatin
Applied Math Solutions.

Monday, November 19, 2007, 10:30AM, Rm. H107, Bldg. 217.

Experimental results indicate that current resists lack the ability to simultaneously meet the 2006 International Roadmap for Semiconductors goals for Resolution (R), Line-edge/width roughness (LER/LWR), and Sensitivity (S). This behavior, which we term the RLS tradeoff, has also been predicted by modeling which again implies that it will be very difficult for a standard chemically amplified resist to simultaneously have low LER, low dose, and high resolution. The fact that the three most critical resist characteristics are currently in opposition raises serious questions about how to alter resist chemistry to make it capable of ultimately delivering the needed performance for EUV lithography. In this work we present an experimentally validated LER model and use it to explore the impact on the RLS tradeoff of three different properties: (1) Anisotropic acid diffusion. Anisotropic diffusion alters a fundamental assumption in the original model and hence alters the RLS tradeoff. We will show how anisotropic diffusion can improve the tradeoff. (2) Increased quantum yield, Q. Increasing Q, i.e., number of acids generated per photon, directly improves sensitivity. We show how the various methods for increasing Q impact the deprotection distribution and hence the LER and resolution. (3) Secondary electrons. The EUV exposure mechanism involves secondary electrons. The finite mean free path (MFP) of these electrons nominally decreases resolution, an effect which has not been accounted for in previous models. However, if these electrons can be harnessed to significantly increase Q while keeping their MFP small it may be possible to use them to improve the RLS tradeoff. This work was supported by SEMATECH. For further information contact James Liddle, 301-975-6050, james.liddle@nist.gov 

HIGH RESOLUTION FABRICATION TECHNIQUES


Guy A. DeRose
California Institute of Technology, Electrical Engineering and Applied Physics.

Wednesday, November 14, 2007, 1:30PM, Rm. H107, Bldg. 217.

The development of high resolution lithography and pattern transfer methods has resulted in extremely complex electronic, photonic, mechanical, and fluidic devices. This capability is now widely available through foundries and cleanrooms. In pursuing further miniaturization of nanodevices and their integration into functional systems, accurate and reproducible modification of these structures becomes necessary. Recent advancements in focused ion beam (FIB) systems enable us to perform more accurate and rapid modifications of device geometries. In particular, dual-beam FIB systems, which combine the diagnostic tools of analytical electron microscopes with the modification accuracy and control over surface chemistries of ion beams, enable the tuning and improvement of conventional micro-devices. Applications of state-of-the-art nanofabrication through electron beam lithography and dry etching will be presented, as well as examples of how such fabricated devices can be modified with FIB etching to improve their performance.

For further information contact J. Alexander Liddle, 301-975-6050, james.liddle@nist.gov 

DESIGN, FABRICATION AND CHARACTERIZATION OF DIAMOND BASED PHOTONIC MICROCAVITIES


Dr. Chiou-Fu Wang
University of California, Santa Barbara.

Tuesday, November 13, 2007, 1:30PM, Rm. H107, Bldg. 217.

Negatively charged nitrogen-vacancy (N-V) centers in diamond have attracted much attention recently due to their unique properties, such as very long spin lifetimes and their suitability for single photon sources at room temperature. When such sources are matched by the formation of high quality cavities, opportunities arise for enhancement and control of the optical transitions associated with N-V centers. This talk will focus on fabrication and characterization of the photonic microcavities, such as microdisks and photonic crystal structures, in nanocrystalline diamond. Optical characterizations provide insights to scattering loss in these structures, which hints the limitation of this material. I will also discuss our strategies of constructing similar structure in single crystal diamond, and show some preliminary results. For further information contact Kartik Srinivasan, 301-975-5938, kartik.srinivasan@nist.gov 

BIOLOGICAL MACROMOLECULES AS SCAFFOLDING FOR PRECISELY ENGINEERED NANOSTRUCTURES


Lee Makowski
Biosciences Division, Argonne National Laboratory. Argonne, IL

Friday, October 26, 2007, 1:30PM, Room C103-C106, Building 215.

We are currently developing a system for using biological macromolecules as scaffolding for the construction of nanostructures comprising multiple inorganic nanoparticles. The system utilizes the geometry of the macromolecules to define the three-dimensional arrangement of inorganic particles in the structure. A massively parallel assembly process will be used to provide for the mass production of identical nanostructures. We envision applications to include, for example, (i) construction of small assemblies of metallic nanoparticles to form nanolenses capable of focusing surface plasmons and (ii) the construction of magnetic cellular automata. For further information contact James Alexander Liddle, 301-975-6050, liddle@nist.gov 

SMART TEMPLATES WITH ACTIVE CONFINEMENT FOR NEW MATERIALS AND DEVICES


Alexander Sidorenko
Professor.

Monday, October 15, 2007, 10:30AM, Rm. H107, Bldg. 217.

I will present the design of nanostructured polymer materials employing self-organization phenomena and active templates. We fabricate and investigate smart surfaces and devices for wide range applications spanning from molecular electronics and optical devices to bio-inspired materials and cell adhesion control. Several recent examples of "smart" materials and surfaces will be discussed:
- grafted polymers as smart templates with active confinement
- reactive multi-dimensional nanoscopic templates from block copolymers
- templated synthesis of hybrid polymer-inorganic nanometer scale devices
- synthetic polymers - protein hybrid polymer brushes for biological applications.

For further information contact Nikolai Zhitenev, 301-975-6039, nikolai.zhitenev@nist.gov 

STUDYING A SINGLE KONDO ATOM IN A PRECISELY KNOWN ANISOTROPIC ENVIRONMENT


Sander Otte
Leiden Institute of Physics, Leiden University.

Thursday, September 27, 2007, 10:30AM, Rm. H107, Bldg. 217.

Using a 3He STM, we employ a new technique called Spin Excitation Spectroscopy to study the magnetic properties of single d-metal atoms – Mn, Fe and Co – on a thin insulating copper nitride layer. This surface provides a well defined anisotropic environment that partly breaks the degeneracy of the spin states even in the absence of an external magnetic field. For Co this results in an effective S = ½ system that exhibits Kondo behavior. We show that the splitting of the Kondo peak, though in itself a multi-body effect, is dictated by the quantum mechanics of the single spin. By performing atom manipulation we can let a Kondo spin interact with other spins and tune their coupling strength, opening the way to building Kondo chains and lattices. For further information contact Joseph A. Stroscio, 301-975-3716, joseph.stroscio@nist.gov 

MICRO-SCALE NANOPOSITIONING MECHANISMS FOR PRECISION NANOINSTRUMENTATION


Jason Gorman
Intelligent Systems Division, National Institute of Standards and Technology (N.I.S.T).

Wednesday, August 8, 2007, 1:30PM, Rm. H107, Bldg. 217.

A class of nanopositioning mechanisms based on MEMS technology has been developed for applications in nanotechnology that require precision motion control. This class includes in-plane XY nanopositioners driven by thermal actuators, and out-of-plane nanopositioners actuated by electromagnetic forces. Miniaturization provides a number of benefits for nanoinstrumentation, including higher bandwidth, in situ sensing and actuation, and a reduction in metrology errors. Our research aims to maximize these benefits, and apply the micro-scale nanopositioners to nanomanipulation, atomic force microscopy, and nanomechanical material testing, although many other applications are possible. In this presentation, the design concepts and fabrication processes for several different mechanisms will be discussed. A model-based control approach, which has resulted in motion control with 5 nm resolution over a range of 2 um, will also be presented.

For further information contact J. Alexander Liddle, 301-975-6050, james.liddle@nist.gov 

ON CONTROL OF MICRO-SCALE SYSTEMS: COMBINING MODELING, CONTROL, SENSING AND ACTUATION TO ACHIEVE NEW CAPABILITIES


Benjamin Shapiro
Aerospace Engineering Department, University of Maryland.

Thursday, July 26, 2007, 10:30AM, Rm. C103, Bldg. 215.

Modeling, design and control of micro-scale devices for bio-chemical and medical applications. The focus is on applications where control can dramatically improve or allow new system capabilities. We consider all aspects of the design pathway from initial application choice, to system modeling, device fabrication, phrasing of design tasks as tractable mathematical problems, control algorithm development and experimental demonstration and validation. Projects include steering of cells by micro flow control, precision control of electrowetting flows, modeling and control of bio-compatible conducting plastic micro-actuators, monitoring cells on chip and magnetically targeted deep-tissue drug delivery. For further information contact Jabez McClelland, 301-975-3721, jabez.mcclelland@nist.gov



MEMS SPATIAL LIGHT MODULATORS


Dr. Vladimir Aksyuk
Bell Labs .

Wednesday, June 27, 2007, 2:30PM, Rm. H107, Bldg. 217.

Micro Electro Mechanical Systems (MEMS) technology enables mass production of microscopic mechanical systems containing millions of individual elements through batch fabrication techniques. High speed, excellent optical quality and dense integration of individually controlled micromechanical devices onto a single silicon chip allows an unprecedented degree of manipulation of the optical field by MEMS Spatial Light Modulators (SLMs) for applications in projection, adaptive optics, spectroscopy, and telecommunications. Recent advances reveal potential to bring revolutionary new capabilities in ophthalmology, optical sensing, imaging and metrology, information processing, free space communications, microscopic manipulation and quantum computing. For further information contact J. Alexander Liddle, 301-975-6050, james.liddle@nist.gov 

SPATIAL RESOLUTION LIMITS OF ELECTRON BEAM NANOPATTERING


Leonidas Ocola
Center for Nanomaterials, Argonne National Laboratory . Argonne, IL

Monday, June 25, 2007, 10:30AM, Rm. H107, Bldg. 217.

Electron beam lithography has represented the most effective way to pattern materials at the nanoscale for almost four decades. The success of e-beam lithography depends on multiple factors such as electron optics, the interaction between the beam of electrons and the pattern material (resist), and the interaction between the developer and the exposed resist. At the Center for Nanoscale Materials at Argonne we use a Raith 150 ebeam tool that operates at 30 KV and a JEOL 9300 ebeam tool that operates at 100KV. We will discuss the spatial resolution achievable with electron beam lithography by cold [1] and hot development [2, 3].
Our results show improved resolution and contrast for resists that are exposed by polymer chain scission. Others results [2, 3] show that similar effect happens with crosslinked resist in opposite manner. Both share the common dissolution mechanism of molecular weight based dissolution.
These results have impact in the photomask industry and other manufacturers that require squeezing out as much resolution out of their existing tools and materials. It is found that, even with the improvement by cold or hot development, there is a “shot noise” of 2% uncertainty limit that is not surpassed for resists exposed at 100 kV. This explains why high throughput and high resolution electron-beam nanolithography is not possible.
References 1. L. E. Ocola, J. Vac. Sci. Technol, B 24, 3061 (2006) 2. M. Häffner, A. Haug, A. Heeren, M. Fleischer, H. Peisert, T. Chassé, D. P. Kern, EIPBN 2007 proceedings, to be published. 3. S. S. Choi Choi, N. Jin, V. Kumar, M. Shannon, and I. , N. Jin, V. Kumar, M. Shannon, and I. Adesida, EIPBN 2007 proceedings, to be published.

For further information contact J. Alexander Liddle, 301-975-6050, alex.liddle@nist.gov 
 

CNST Seminar Series

FABRICATION AND CHARACTERIZATION OF NOVEL PROBES AND DEVICES FOR DATA STORAGE TECHNOLOGY


Thomas W Clinton
Research Staff Member, Seagate Research. Pittsburgh, PA.

Thursday, May 31, 2007, 10:30AM, Rm. H107, 217 Bldg.

The $100-billion data-storage market is driven by, arguably, the fastest moving technology in high-tech industry, where the nano-scale is already commonplace in products. Instruments that aid in the fabrication and characterization of advanced devices are critical to sustaining the growth of storage technology, where not only are bits measured in nanometers, but data rates (> GHz) have driven timescales sub nanosecond. For magnetic recording technology in particular, there are many physical barriers that need to be overcome to further increase the density of bits on a disc (areal density) in the endless push for more memory. Smaller bits need higher anisotropy to be thermally stable, which requires a tinier source (the writer) to deliver larger magnetic fields (> 2 Tesla) in an even shorter timeframe. This is a daunting task, but a great opportunity for science and engineering. In this talk, I will discuss some of our work that explores the effects of shrinking bits and short timescales, focusing on two measurement tools, in particular, that aid our characterization and fabrication: a dualbeam FIB/SEM and a recently developed ferromagnetic resonance (FMR) probe1.

1. D.I. Mircea and T.W. Clinton, Appl. Phys. Lett. 90, 142504 (2007).

For further information contact Daniel T. Pierce, 301-975-3711, daniel.pierce@nist.gov 
 

Electron Physics Group Seminar Series

THZ SPINPLASMONICS: A NEW DIRECTION FOR ACTIVE PLASMONICS


Abdulhakem Y. Elezzabi
Professor, Ultrafast and Nanophotonics Laboratory, University of Alberta. Edmonton,

Thursday, May 10, 2007, 10:30AM, Rm. H107, 217 Bldg.

Surface plasmon (SP) waves have been studied on a wide range of geometries and at frequencies spanning from the visible down to the radio spectral range. In particular in the terahertz (THz) spectral range, SP waves confined on metallic surfaces have been widely investigated for their potential applications in THz photonics. In this talk, I will discuss near-field interaction of THz radiation with dense random metallic media. Such media exhibit electromagnetic properties that significantly differ from those of continuous metallic structures or surfaces. In particular, I show that THz radiation can be transmitted through ensembles of sub-wavelength-size metallic particles over distances several orders of magnitude greater than the radiation bulk absorption depth. In the second portion of this talk, I will demonstrate several new routes towards realizing active control of THz plasmons via influencing SP nanometer and quantum transport. By exploiting the quantum state of the electron (i.e its spin of electron), I will present a novel method for generating spin-polarized plasmons where active control of the spinplasmonic state is achieved by magnetic field. I envision the realization of a multitude of next generation actively-controlled spinplasmonic devices. For further information contact Alexander Liddle, 301-975-6050, alex.liddle@nist.gov 
 

EPG Seminar Series

FABRICATION AND CHARACTERIZATION OF NOVEL PROBES AND DEVICES FOR DATA STORAGE TECHNOLOGY


Thomas W. Clinton
Research Staff Member, Seagate Research. Pittsburgh, PA

Thursday, May 3, 2007, 10:30AM, Rm. H107, 217 Bldg.

The $100-billion data-storage market is driven by, arguably, the fastest moving technology in high-tech industry, where the nano-scale is already commonplace in products. Instruments that aid in the fabrication and characterization of advanced devices are critical to sustaining the growth of storage technology, where not only are bits measured in nanometers, but data rates (> GHz) have driven timescales sub nanosecond. For magnetic recording technology in particular, there are many physical barriers that need to be overcome to further increase the density of bits on a disc (areal density) in the endless push for more memory. Smaller bits need higher anisotropy to be thermally stable, which requires a tinier source (the writer) to deliver larger magnetic fields (> 2 Tesla) in an even shorter timeframe. This is a daunting task, but a great opportunity for science and engineering. In this talk, I will discuss some of our work that explores the effects of shrinking bits and short timescales, focusing on two measurement tools, in particular, that aid our characterization and fabrication: a dualbeam FIB/SEM and a recently developed ferromagnetic resonance (FMR) probe. For further information contact Daniel T. Pierce, 301-975-3711, daniel.pierce@nist.gov 
 

EPG Seminar Series

THE PHYSICS OF NANOMAGNETS MADE VIA BLOCK COPOLYMER TEMPLATES


Mark T. Tuominen

Professor, Department of Physics, University of Massachusetts. Amherst, MA Friday, April 20, 2007, 2:30PM, Rm. H107, 217 Bldg.

Data storage, electronics and other industrial areas rely on the advancement of magnetic materials technologies. One route is through the creation of nanomagnets with well defined shape, orientation, crystallinity and magnetic properties. This talk will discuss recent work at the University of Massachusetts at Amherst to advance the field of nanomagnetics by using diblock copolymer films as pattern templates in conjunction with various deposition techniques to create various types of nanomagnets. For further information contact J. Alexander Liddle, 301-975-6050, alex.liddle@nist.gov 
 

CNST Seminar Series

MAGNETISM ON THE NANOSCALE


Andreas Heinrich
IBM Almaden Research Center. San Jose, CA

Thursday, April 19, 2007, 10:30AM, Rm. C103-C106, 215 Bldg.

Understanding and controlling the magnetic properties of nanoscale systems is crucial for the implementation of future data storage and computation paradigms. Here we show how the magnetic properties of individual atoms can be probed with a low-temperature, high-field scanning tunneling microscope when the atom is placed on a thin insulator. In extended one-dimensional spin chains, which we build one atom at a time, we find strong spin-coupling into collective quantum-spins, even for the longest chains of length 3.5nm. The spectroscopic results can be understood with the model of spin-excitations in a system with antiferromagnetic coupling, controlled on the atomic scale. For further information contact Joseph Stroscio, 301-975-3716, joseph.stroscio@nist.gov 
 

CNST Seminar Series

TRANSPARENT OXIDE SEMICONDUCTORS FOR FLEXIBLE AND NANO-ELECTRONICS


Gregory S. Herman
Hewlett-Packard Company. Corvallis, OR

Thursday, April 12, 2007, 10:30AM, Rm. C103-C106, 215 Bldg.

Transparent oxide semiconductors have been extensively studied due to the direct commercial applications including displays, solar cells, sensors, and energy-efficient windows. There has been an increased interest in transparent electronics due to the possibility of forming active transparent components, which can enable new optoelectronic applications. The synthesis, characterization, and integration of these materials will be presented. We are focusing on several ternary oxides, including Zn2In2O5 and ZnSnO3. These materials have been determined to be amorphous as deposited and have excellent electrical properties when used as channel materials for thin film transistors on flexible substrates. Initial results will also be presented for ternary oxide nano-materials.

For further information contact Jason Crain, 301-975-3744, jason.crain@nist.gov 
 

CNST Seminar Series

HIGH-RESOLUTION ATOMIC FORCE MICROSCOPY: WHERE ARE WE, AND WHERE WILL THE FUTURE TAKE US?


Udo D. Schwarz
Associate Professor, Department of Mechanical Engineering, Yale University. New Haven, CT

Thursday, March 22, 2007, 10:30AM, Rm. C103-C106, 215 Bldg.

Since its invention about two decades ago, atomic force microscopy (AFM) has developed into one of the most frequently used techniques for structural analysis at the nanometer scale due to its almost universal applicability and easy sample preparation. Despite this success and the widespread availability of commercial AFM systems, high-resolution imaging providing molecular or even atomic-scale information has remained a challenge. In this talk, I will discuss the obstacles that have to be overcome to achieve high-resolution images using AFM. As we will see, the techniques that we have to apply vary depending on the specific kind of samples we are interested in. While soft biological samples require liquid environment and extremely low tip-sample interaction forces, other samples are best imaged in ultrahigh vacuum, possibly even at low temperatures. Whatever the sample, however, AFM is in principle able to deliver high-resolution images on all material classes, no matter how delicate. An example is given in the illustration, featuring a 3D atomic-scale image of crystalline xenon, which cannot be obtained with any other technique. We will further elaborate where the limitations of current state-of-the-art high-resolution AFM imaging are, and where possibilities for progress exists.

For further information contact Daniel T. Pierce, 301-975-3711, daniel.pierce@nist.gov 
 

EPG Seminar Series

MATERIALS DESIGN IN THE NANOMETER RANGE AT EMPA IN SWITZERLAND


Louis Schlapbach
CEO of EMPA and Prof. Experimental Physics, ETH. Zurich, Switzerland

Thursday, March 15, 2007, 10:30AM, Rm. H107, 217 Bldg.

EMPA, a Materials Science and Technology Institution in the domain of the Swiss Federal Institute of Technology (ETH), runs an application oriented nanotechnology program. I will present highlights of our work in the following areas: carbon nanotube field emitters, hydrogen defects in graphitic nanostructures, nanostructured hard coatings for reduced wear and friction, the synthesis, properties and use of nanoparticles, nanoparticulate functionalized fibers, nanosized particles in emissions from combustion processes, risk analysis, and the 3D-analysis of cementous nanopores using FIB techniques. EMPA welcomes collaborations and invites guest scientists and engineers. For further information contact Daniel T. Pierce, 301-975-3711, daniel.pierce@nist.gov 
 

CNST Seminar Series- Special Joint Seminar

SMALL-SCALE, SIX-AXIS NANOPOSITIONERS: NEW CONCEPTS AND PERFORMANCE LIMITS FOR NANOMANUFACTURING EQUIPMENT/INSTRUMENTATION


Martin L. Culpepper
Rockwell International Associate Professor, Massachusetts Institute of Technology. Cambridge, MA

Monday, March 12, 2007, 10:30AM, Rm. C103-C106, 215 Bldg.

The purpose of my work is to generate new concepts and the corresponding knowledge that enables the design/fabrication/implementation of small-scale, six-axis nanopositioning systems. In this talk, we will discuss the utility of smaller-scale nanopositioners and their performance limits. We will examine several new machine elements (silicon-based elements and nascent designs for carbon nanotube-based elements) and the nanopositioners that have been created using these elements. We will also discuss the high-level aspects of case studies where these devices are being created for probe-based nanofabrication processes. The case studies are the result of collaborations wherein we have partnered with process researchers in order to co-develop process-equipment pairs for future nanofabrication processes. For further information contact Jabez McClelland, 301-975-3721, jabez.mcclelland@nist.gov 
 

CNST Seminar Series

ELECTRON CONDUCTING STATES IN NANO- AND MESOSCALE MOLECULAR DEVICES


Nikolai Zhitenev
Bell Labs., Alcatel-Lucent. Murray Hill, NJ Thursday,

March 1, 2007, 10:30AM, Rm. C103-C106, 215 Bldg.

Organic materials can offer new electronic functionality not available in the inorganic devices. However, the integration of organics within nanoscale electronic circuitry poses new challenges for material physics, chemistry and nanofabrication. I will discuss different approaches to engineer useful electronic properties in small molecular devices. In the first case, the electronic functionality is to be provide by the backbones of short molecules. We have developed a set of fabrication and characterization techniques allowing us to build devices with self-assembled monolayers from nearly single-molecule size up to ~300nm on a side. In the second approach, we build devices with monolayers of macromolecules. The electronic properties are determined by the composition, the chemical conversions and electric-field-induced chemical reactions of the side groups. For further information contact Joseph Stroscio, 301-975-3716, joseph.stroscio@nist.gov 
 

EPG Seminar Series

TAGGING OF SINGLE BARIUM IONS IN LIQUID AND SOLID XENON WITH LASERS


William M. Fairbank, Jr.
Department of Physics, Colorado State University. Fort Collins, CO

Thursday, February 15, 2007, 10:30AM, Rm. H107, 217 Bldg.

We are developing techniques to detect single 136Ba+ ions from rare neutrinoless double beta decay events (one in 5-10 years) in a large volume (1-10 tons) of liquid xenon-136. We are exploring two methods, direct fluorescence detection of single Ba+ ions in the liquid xenon and detection of single Ba+ ions in solid Xe on the end of an optical fiber. Our colleagues at Stanford are developing another method of grabbing and detecting the Ba+ ions in a linear ion trap. Progress on these methods will be reported. For further information contact Jabez McClelland, 301-975-4675, jabez.mcclelland@nist.gov 
 

CNST Seminar Series

A SUMMARY OF JOINT INDUSTRY STRATEGIC RESEARCH AND EMERGING MATERIALS WITH HIGH APPLICATION IMPACT POTENTIAL


Daniel Herr
Director, Nanomanufacturing Sciences Research, Semiconductor Research Corporation. Durham, NC

Thursday, February 8, 2007, 10:30AM, Rm. C103-C106, 215 Bldg.

In 2006, the Semiconductor Research Corporation’s research community, with colleagues from several other industries and government laboratories, identified a joint set of critical research needs1 in the area of nanomaterials modeling and verification. The goal was to develop an enhanced predictive capability of nanomaterials structure-property correlations and enable robust high performance application specific nanomaterials by design. Predictive models are needed for the integrated optimization of: the synthesis of nanoparticles, surface chemical reactivity, electronic and transport properties, nanomechanical properties, properties of self-assembled materials, and other application properties. Some nanomaterials families possess unique properties that make them candidates to enhance or replace conventional materials and approaches, but the need for optimization of multiple properties requires models that correlate atomic and nanostructure and local environments to desired properties. This presentation will summarize a joint set of strategic modeling and characterization needs, which are shared by multiple industries, and propose a framework for collaboratively engaging industrial, academic, and government research communities. Additionally, it will provide a summary of strategic research opportunities in several enabling material systems and emerging high potential impact application areas. For further information contact Mark Stiles, 301-975-3745, mark.stiles@nist.gov 
 

CNST Seminar Series

TECHNOLOGY ROADMAPPING AT BELL LABS


Renato Camarda
LGS- Bell Laboratories. Murray Hill, NJ

Tuesday, February 6, 2007, 10:30AM, Shops Conference Room, 304 Bldg.

I will present a technology management methodology developed over the past decade at Bell Laboratories. This tool was designed to help link strategic business objectives to technology investments and to generate implementation plans in the context of a large, multinational corporation. However, the techniques I will describe can equally well be applied to research projects on any scale. I will illustrate the discussion with examples taken from a number of efforts undertaken at Lucent Technologies. Attendance restricted to government employees only. For further information contact Alexander Liddle, 301-975-6050, alex.liddle@nist.gov 
 

CNST Seminar Series

SMALL-SCALE, SIX-AXIS NANOPOSITIONERS: NEW CONCEPTS AND PERFORMANCE LIMITS FOR NANOMANUFACTURING EQUIPMENT/INSTRUMENTATION


Martin L. Culpepper
Rockwell International Associate Professor, Massachusetts Institute of Technology. Cambridge, MA

Tuesday, January 30, 2007, 1:30PM, Rm. C103-C106, 215 Bldg.

*Special joint seminar with the NIST Intelligent Systems Division* Six-axis nanopositioners are important because they set many of the limits on our ability to measure/understand and control/affect nano-scale geometries/phenomena. They are relevant to (a) instruments that enable the measurement/understanding of small-scale geometries/phenomena and (b) equipment that enables the fabrication of parts that rely upon small-scale geometries/phenomena. Advances in nanopositioning technology make it possible to (a) increase the type/pace of scientific discoveries (via instruments) and (b) improve the pace/quality with which these discoveries are put into practice (via equipment). We find a growing number of applications within nanomanufacturing that require small-scale nanopositioners in order to achieve viable speed (kHz), resolution (nanometers- Angstroms), cost ($10s/device) and stability ( Angstroms/min) levels. These levels of performance are usually impossible to obtain with macro-scale nanopositioners. It is also impractical to obtain these levels by miniaturizing macro-scale nanopositioner designs. New concepts, fabrication processes and performance models are required to realize small-scale nanopositioners that have inherent benefits with respect to the aforementioned performance requirements.

The purpose of my work is to generate new concepts and the corresponding knowledge that enables the design/fabrication/implementation of small-scale, six-axis nanopositioning systems. In this talk, we will discuss the utility of smaller-scale nanopositioners and their performance limits. We will examine several new machine elements (silicon-based elements and nascent designs for carbon nanotube-based elements) and the nanopositioners that have been created using these elements. We will also discuss the high-level aspects of case studies where these devices are being created for probe-based nanofabrication processes. The case studies are the result of collaborations wherein we have partnered with process researchers in order to co-develop process-equipment pairs for future nanofabrication processes.

For further information contact Jabez McClelland, 301-975-3721, jabez.mcclelland@nist.gov 
 

CNST Seminar Series

MEASUREMENT AND CHARACTERIZATION CHALLENGES FOR BEYOND CMOS NANOELECTRONICS


George I. Bourianoff
Technology Manufacturing Group, Intel Corporation. Austin, TX

Thursday, January 25, 2007, 10:30AM, Rm. C103-C106, 215 Bldg.

Intel believes that silicon based CMOS technology will remain the workhorse of information processing technology for approximately the next 15 years and beyond that, silicon will form the platform upon which alternative information processing technologies will be built and integrated. Intel's research indicates that CMOS technology as it exists today can be extended significantly by using new materials, processes, and structures. Beyond that, alternative logic technologies will begin to appear based on alternative methods of storing computational state and processing information. There are many challenges and issues which must be faced in order to develop alternative logic technologies including noise immunity, interconnect issues, nanoscale thermal management, material integration and fabrication issues. This presentation will survey the long range research relating to the search for beyond CMOS logic alternatives. It will focus on measurement and characterization challenges associated with using alternative state variables such as magnetization, polarization and spin and the interaction of these variables with applied and induced fields. The measurement and characterization challenges are magnified by the likely introduction of new material systems and the need to ultra high spatial and temporal resolution. This presentation will draw heavily on ideas developed within the ITRS ERD and implemented in the Nanotechnology Research Initiative and Focused Center Research Programs. For further information contact Mark Stiles, 301-975-3745, mark.stiles@nist.gov 
 

CNST Seminar Series

MAPPING UNCOMPENSATED SPINS IN EXCHANGE-BIASED SYSTEMS


Hans J. Hug
Empa. Dubendorf, Switzerland Wednesday,

January 17, 2007, 10:30AM, Rm. C103-C106, 215 Bldg.

Magnetic Force Microscopy is an ideal tool to image magnetic stray fields emanating from surfaces but also from hidden interfaces of magnetic or superconducting samples. A lateral resolution of 10nm is routinely obtained on flat samples. Tip calibration techniques were developed for a quantitative evaluation of the magnetic surface charge or surface dipole density from the measured MFM signal. The latter was performed to map the spatial density of pinned uncompensated spins (UCS) in exchange-biased ferromagnet/antiferromagnet multilayers. In order to further characterize these samples, different magnetization histories in magnetometry and magnetic force microscopy measurements were used advantageously to demonstrate the co-existence of pinned UCS that are parallel and antiparallel to the cooling field in metallic (IrMn) and oxidic (CoO) EB systems. We found that the exchange-bias-effect (EB-effect) is a result of pinned interfacial UCS, which are antiparallel to the spins of the ferromagnet. The often observed positive vertical shift of the magnetization loop after field cooling is due to pinned UCS that align parallel to the cooling field, but are of little importance for the EB-effect. Whereas magnetic force microscopy seems to reach its final state of development, considerable instrumental progress remains to be achieved in scanning force microscopy with true atomic resolution. A scanning force microscope optimized for surface science would allow the simultaneous measurement of vertical and lateral forces, energy loss and tunneling current. Our recent developments will be discussed. For further information contact Daniel T. Pierce, 301-975-3711, daniel.pierce@nist.gov 
 

CNST Seminar Series

IMAGING MAGNETIC SURFACES WITH ATOMIC RESOLUTION


Mattias Bode

University of Hamburg, Institute of Applied Physics and Microstructure Research Center . Hamburg, Germany

Friday, January 12, 2007, 10:30AM, Rm. C103-C106, 215 Bldg.

Fueled by the ever increasing data density in magnetic storage technology and the need for a better understanding of the physical properties of magnetic nanostructures, there exists a strong demand for high resolution, magnetically sensitive microscopy techniques. The technique with the highest available resolution is spin-polarized scanning tunneling microscopy (SP STM) which combines the atomic resolution capability of conventional STMs with spin sensitivity by making use of the tunneling magnetoresistance effect between a magnetic tip and a magnetic sample surface. Beyond the investigation of ferromagnetic surfaces, thin films, and epitaxial nanostructures with unforeseen precision, it also allows the achievement of a long-standing dream: the real space imaging of atomic spins in antiferromagnetic surfaces. The lecture addresses a wide variety of phenomena in surface magnetism which in most cases could not be imaged directly before the advent of SP-STM. After starting with a brief introduction of the basics of the contrast mechanism, recent major achievements will be presented, like the direct observation of the atomic spin structure of domain walls in antiferromagnets and the visualization of thermally driven switching events in superparamagnetic particles consisting of a few hundreds atoms only. To conclude the lecture, recently observed complex spin structures containing 15 or more atoms will be presented. For further information contact Jabez McClelland, 301-975-3721, jabez.mcclelland@nist.gov 
 

CNST Seminar Series

PHAT PHOTONS FOR NIFTY NANOSCIENCE


Steven R. J. Brueck
Center for High Technology Materials, University of New Mexico. Albuquerque, NM

Tuesday, January 9, 2007, 10:30AM, Rm. C103-C106, 215 Bldg.

Progress in optical lithography has paced the enormous progress in integrated circuits. Thus, the question of the ultimate capabilities of optical lithography is of great importance as we proceed into the deep sub-wavelength regime. The spatial frequency transmission bandwidth of free-space is 2/?, leading to a dense (equal line/space) pattern at a half-pitch of ?/4 (or 48 nm for a 193-nm??). Immersion provides another factor of ~ 1.44 (H2O) or greater down to a ½ pitch CD < 33 nm. Nonlinear processes, based on photore-sist chemistry and pattern transfer, allow further extension of optics beyond the single-exposure linear-systems limits, much as frequency multiplication processes allow extension of fundamental laser frequen-cies (cf. Fig. 1). The conclusion is that there is no fundamental limit to the resolution of optical lithog-raphy; there remain process latitude and manufacturing (e.g. cost) issues. For many nanotechnology applications, large numbers of nanostructures covering a large sample area with a well-defined long-range order are required. One such example is a metamaterial with a structure- (as opposed to material-) dependent resonance. Fig. 2 shows an infrared metamaterial (an assemblage of LC tank circuits). Negative-index materials (NIMs) are another emerging area. Photonic crystals –periodic arrays of nanoscale structures (with or without aperiodic defects) providing another example of the exciting physics accessible with current interferometric lithography capabilities. Nanostructuring for semiconductor materials development and nanofluidics for biological applications are other emerging re-search directions. The overall message is that a nanoscale lithography capability enables many excit-ing nanotechnology research directions. For further information contact Jabez McClelland, 301-975-3721, jabez.mcclelland@nist.gov 
 

CNST Seminar Series

NANOELECTROMECHANICAL SENSING AND METROLOGY: RECENT PROGRESS


Kamil L. Ekinci
Aerospace and Mechanical Engineering, Boston University. Boston, MA

Thursday, January 4, 2007, 10:30AM, Rm. C103-C106, 215 Bldg.

Nanoelectromechanical systems (NEMS) have been at the center of recent applied and fundamental research. Most NEMS are resonant devices — much like simple tuning forks — with submicron dimensions. In this size regime, NEMS come with extremely high fundamental resonance frequencies, diminished active masses and tolerable force constants; the quality (Q) factors of resonance are in the range Q~103-105. These attributes collectively make NEMS suitable for a multitude of technological applications — such as ultrasensitive force and mass sensing, narrow band filtering, and time keeping. From a fundamental physics point of view, NEMS are expected to enable the observation of quantum behavior in mesoscopic mechanical systems. This presentation will start with a brief description of our recent work on nanomechanical mass sensing. It will then outline some of the challenges involved in realizing a practical NEMS mass sensor and focus on our efforts in addressing these challenges. One of the challenges, namely the operation of a nanomechanical resonator in a rarefied gas atmosphere, has led us to re-investigate a well-known fluid dynamics problem: Stokes’ second problem of an oscillating plate in a fluid. At the frequencies of NEMS motion, Stokes’ second problem needs to be reformulated in order to accurately describe NEMS motion. On the other hand, our efforts to develop tunneling displacement transducers have resulted in progress towards a functional radiofrequency scanning tunneling microscope (STM). For further information contact Joseph Stroscio, 301-975-3716, joseph.stroscio@nist.gov
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