California NanoSystems Institute
CNSI
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December 07, 2004

Robert Chau
Intel
Silicon and Non-Silicon Nanotechnologies for High-Performance and Lower-Power Logic Transistor Applications
Abstract:

Moore's Law states that the number of transistors per integrated circuit doubles every 24 months, and it has been the guiding principle for the semiconductor industry for over 30 years. The sustaining of Moore's Law, however, requires continual transistor miniaturization. The physical gate length of the Si transistors used in our current 90nm generation node is ~50nm. It is projected that the size of the transistors will reach ~10nm in 2011. Through silicon innovations such as strained-Si channels, high-K/metal-gate gate stacks [Ref. 1], and the non-planar "Tri-gate" CMOS transistor architecture [Ref. 2], CMOS transistor scaling and Moore's Law will continue at least through early next decade. By combining silicon innovations with other novel nanotechnologies on the same silicon platform, it is expected that Moore's Law will extend well into the next decade. Recently there has been tremendous progress made in the research of novel nanotechnology for future nanoelectronics applications. In particular, several novel nanoelectronic devices such as carbon-nanotube field effect transistor (FET), Si and non-Si nanowire FETs, and planar III-V compound semiconductor FET, all hold promise as device candidates to be integrated onto the silicon platform for enhancing circuit functionality and also for extending Moore's Law [Ref. 3]. In this talk, I will describe the most recent advances made in Si CMOS transistor technology, and also discuss the challenges and opportunities presented by the recent emerging nanoelectronic devices for high-performance, low-power logic applications. A benchmarking methodology to benchmark emerging nanoelectronic devices against existing best Si planar and non-planar logic transistor data will also be presented.

References:

[Ref. 1] R. Chau, et al., "High-K/Metal-Gate Stack and Its MOSFET Characteristics," IEEE Electron Device Letters, Vol. 25, No. 6, pp.408-410, June 2004.

[Ref. 2] R. Chau, et al., "Advanced Depleted Substrate Transistors: Single-gate, Double-gate and Tri-gate," Extended Abstracts of International Conference on Solid State Devices & Materials (SSDM), Nagoya, Japan, p.68-69, 2002.

[Ref. 3] R. Chau, "Benchmarking Nanotechnology for High-Performance and Low-Power Logic Transistor Applications," Proceedings of 4th IEEE Conference on Nanotechnology (IEEE-Nano 2004), Munich, Germany, Aug 2004.

Biography:

Dr. Robert Chau is an Intel Fellow and Director of Transistor Research and Nanotechnology at Intel Corporation. He is responsible for directing research and development in advanced transistors and gate dielectrics for the next and future-generation microprocessor applications. He is also leading research efforts in both silicon and non-silicon nanotechnologies for future device and process applications.

Dr. Chau joined Intel in 1989 and has developed seven generations of Intel gate oxides along with many transistor innovations used in various Intel manufacturing processes and logic products. The latest gate oxide that Dr. Chau has developed for Intelís 90nm technology node has physical thickness of only 1.2nm, which is the thinnest gate oxide ever put into manufacturing. Dr. Chau is the co-inventor and patent holder of the novel SiGe source/drain, strained-Si PMOS transistor used in Intelís 90nm technology node. In addition, Dr. Chau and his team have done pioneer research work in silicon transistor miniaturization (30nm, 20nm, 15nm and 10nm), have demonstrated the non-planar "Tri-gate" CMOS architecture with ideal subthreshold slope and good manufacturability, have demonstrated high-K/metal-gate CMOS transistors with record-setting drive current performance, and have pioneered in the establishment of benchmarking methodologies for benchmarking emerging nanoelectronic devices for logic applications.

Dr. Chau received his B.S., M.S. and Ph.D. degrees, all in electrical engineering, from The Ohio State University. He holds 46 U.S. patents in device and process technologies, and has received six Intel Achievement Awards (Intelís most prestigious award) and 13 Intel Logic Technology Development Division Recognition Awards for his outstanding technical achievements in device and process research and development. Dr. Chau was promoted in 2000 to the rank of Intel Fellow, the companyís highest and most prestigious technical position. Dr. Chau received the 2003 Alumni Professional Achievement Award from The Ohio State University Alumni Association. He has been selected by the Industry Week magazine in December 2003 as one of the 16 "R&D Stars" in the U.S. who "continue to push the boundaries of technical and scientific achievement".

November 30, 2004

Chih-Ming Ho
UCLA


Streaming Video
  

Span the Length Scales by 10^9
Abstract:

The human body is an extremely intelligent and complex adaptive system with a length scale on the order of a meter. The DNA/RNA and protein molecules, which drive its natural processes possess dimensions on the nanometer range. Exploring the governing mechanisms across a wide span of length scales is best stated by P. W. Anderson in his 1972 Science paper as "at each level of complexity entirely new properties appear, and the understanding of the new behaviors requires research which I think is as fundamental in its nature as any other." For example, a cell fuses genetic informatics with nanoscale sensors and actuators to result in perhaps one of the most efficient and autonomous micron-scale "factories". The richness in the science within the three orders of magnitude difference in length scale can not be simply extrapolated from nano molecules and is far beyond our full understanding.

The rapid development of nanotechnology has driven the production of molecular-scale devices towards the functionalizing of materials, directly manipulating of genetic molecules and engineering strains of proteins to possess novel functionalities. The question of how we will span the length scales of these nano-scale capabilities which will eventually enable us to enrich human lives is a not an obvious, but a key task.

Examples will be given in this presentation for illustrating the capability of applying large distributed arrays of micro scale transducers to control a meter-size engineering system of which we do have a fairly good understanding of the governing physical mechanisms across the length scales. On the other hand, this is very different in a natural system, e.g. cell, where the complex networks of signal pathways are still beyond comprehension. With a cocktail of nanoscale cytokines, it is possible to induce the micron-size cells to yield a final desired phenotype. However, exploring all of the possible combinations of these stimuli can result in a very large number of tests which can not be carried out in a realistic time frame to find the optimum combination. Applying the engineering feedback concept, we can search and reach the optimum condition with a very small number of tests. We have demonstrated that in both cases, properly designed time-varying stimulations can self-organize and adjust the functionalities across multiple length scales to efficiently reach the desired control state. This may yield new insight into unlocking and acquiring novel control modalities of the underlying mechanisms that drive the natural processes of life.

November 23, 2004

Supriyo Datta
Purdue University
Current Flow Through Nanoscale Conductors
Abstract:

It is common to differentiate between two ways of building a nanodevice: a top-down approach where we start from something big and chisel out what we want and a bottom-up approach where we start from something small like atoms or molecules and assemble what we want. When it comes to describing electrical resistance, the standard approach could be called a "top-down" one that starts from large conductors and works its way down. In this talk I will present a different view of electrical conduction, one that could be called a "bottom-up" viewpoint. Using examples from the emerging field of molecular electronics I will try to explain the factors that determine the resistance of something really small like a molecule, work my way up and end with what I view as open questions in the field of nanoscale electron transport.

Selected Literature:

S. Datta, "Electrical Resistance: An Atomistic View", Nanotechnology, 15, S433 (2004).

T. Rakshit, G.C. Liang, A.W. Ghosh, S. Datta , "Silicon-based Molecular Electronics", Nano Lett. 4, 1083 (2004).

November 16, 2004


TALK CANCELLED

November 09, 2004

Andre Nel
UCLA
Nanoparticle Toxicity and Health Impacts: What We Have Learned from Pollutant Nanoparticles and Implications for the Nano Industry
Abstract:

There is a lot of interest in the possible adverse biological effects of nanomaterials in humans and the environment. While the risks are often overstated, it is important to develop a sound scientific approach to study the safety and possible toxicological effects of commercial nanomaterials. Not only will this offset unnecessary consern about the possible dangers of nanotechnology, but could prevent a costly public relations debacle for this burgeoning new industry. Our own approach is to work from the basis of the known toxicological effects of pollutant nanoparticles, a.k.a. ultrafine particles, to the applicability or nonapplicability of those principles to commercial nanomaterials. Ultrafine particles cause adverse health effects by promoting inflammation in the lung, cardiovascular system and possibly the brain. The mechanistic basis for these pro-inflammatory effects are the small size and large surface area of these ultrafines, in addition to their ability to penetrate deep into the lung and circulation. Moreover, ultrafine particles also contain organic chemicals and metals which could enhance their toxicity. These particle characteristics combine in the generation of reactive oxygen species and oxidative stress in target cells such as macrophages, epithelial and endothelial cells. Oxidative stress leads to a hierarchical response, in which the initial attempt is antioxidant defense by an adaptive genetic response pathway. If this defense pathway fails, as could happen in genetically susceptible individuals, the activation of pro-inflammatory signaling cascades and mitochondrial perturbation leads to inflammation and cytotoxicity. While some industrial nanoparticles can cause similar effects based on size, surface area and composition, the vast majority of these particles are not available for inhalation exposure, and would only be available to initiate harmful effects if disseminated into soil and water, or directly administered to humans. In addition to using the oxidative stress paradigm, other modes of particle toxicity can be explored by tissue culture cells, animal disease models and nanosensor technology. Creative use of these technologies as the Nano industry advances, should play an important role in demonstrating that the vast majority of Nanomaterials are safe and useful for promoting life on earth.

November 02, 2004

Frank van Veggel
University of Victoria


Streaming Video
  

Lanthanide(III)-Based Photonic Materials and their Applications
Abstract:

Luminescent nanoparticles attract a great deal of interest as components in LEDs, displays, biological essays, optoelectronic devices with nanometer dimensions, and as light source in zero-threshold lasers. Here, we report the synthesis and optical properties of processable Ln3+-doped nanoparticles (5-8 nm), based on insulator and semiconductor materials. Er3+, Nd3+, Ho3+, and Pr3+ emit efficiently in the near-infrared when doped in these materials, at 1.55, 1.33, 1.44, and 1.44 ?m, respectively. Lifetimes are in the ?s to ms range. These emissions cover 1300 to 1600 nm, giving the potential of a compact broad-band optical amplifier. The Ln3+-doped semiconductor nanoparticles show sensitized Ln3+ emission, i.e. the photo-generated exciton of the nanoparticles interact with the Ln3+ ion, leading to energy transfer and thus the excitation of the Ln3+ ion. Incorporation of Ln3+-doped water-soluble LaF3 nanoparticles in sol-gel derived thin films of SiO2 and Al2O3 lead to much more intense emission in the near-infrared than direct doping of these matrices with Ln3+.

A two-parameter model has been developed to account for the multi-exponential decay, which also accurately describes concentration and solvent effects. It has been extended to account for a subtle surface effect on the radiative rate constants of the Ln3+ ions. Epitaxial growth of a shell around the Ln3+-doped core can easily be prepared in one-pot syntheses, which leads to (near) mono-exponential decay of the Ln3+ ions. The two-parameter model is easily modified to account for the effect of the shell.

Initial results of these materials in (polymer-based) devices will be discussed. Amplification at 1319 nm has been demonstrated in a polymer-based waveguide based on LaF3:Nd nanoparticles as the active component. Amplified spontaneous emission has been observed in a microring resonator with LaF3:Nd nanoparticles in the PMMA cladding.

October 26, 2004

Priya Vashishta
USC


Streaming Video
  

Multimillion Atom Simulations of Nanostructured Materials on Parallel Computers
Abstract:

Scalable space-time multiresolution algorithms implemented on massively parallel computers enable large-scale molecular dynamics simulations involving up to a billion atoms. Multimillion atom molecular dynamics simulations are performed to study critical issues in the area of structural and dynamical correlations in nanostructures. Our simulation research is focused on a few semiconductor, ceramic, and metallic nanostructures. These nanostructures systems include: sintering and consolidation, dynamic fracture, nanometer-scale stress patterns in silicon/silicon nitride nanopixels; interfacial fracture; self-limiting growth and critical lateral sizes in gallium arsenide/indium arsenide nanomesas; structural transformation in colloidal semiconductor nanocrystals; nanoindentation of crystalline and amorphous silicon nitride films; and dynamics of oxidation of metallic aluminum nanoparticles.

October 19, 2004

Michael Phelps
UCLA


Streaming Video
  

Molecular Imaging: Probing the Biology of Disease from Mice to Patients
Abstract:

Molecular imaging takes many forms today, from imaging the interaction of isolated molecules to imaging molecular process of disease in patients and everywhere in between. Molecular imaging is by definition any approach with a wide aperture to look across a field of interest to examine the spatial distribution and temporal changes in molecular processes. The image formed and information gained depends on the origin of signals used to produce the image but in all cases they should represent definable molecular processes. In this lecture, four areas will be covered:

1. A historical perspective about the good and bad that happens when you invent a new technology.
2. Explore a pathway from large-scale in vitro measurements of systems biology in cells with nanotechnologies to progressively smaller scale measures in mice to patient based on knowledge from large-scale measures.
3. Discussion of why molecular therapeutics are failing and succeeding and how molecular imaging is helping to illuminate a new discovery pathway.
4. Use of integrated microfluidics to build biomarkers for molecular imaging.

Biography:

Dr. Phelps earned B.S. degrees in chemistry and mathematics at Western Washington State University in 1965, and a Ph.D. in chemistry, at Washington University, St. Louis, in 1970. Subsequently, he was on the medical school faculty of Washington University (1970-75), University of Pennsylvania (1976) and UCLA (1976-present). Dr. Phelps is the inventor of the Positron Emission Tomography (PET) scanner. PET is a molecular imaging technique that allows scientists and physicians to image and measure the chemistry and biology of the living body in health and disease, from mouse to man, from metabolism to gene expression. PET is part of the changes occurring as biology and medicine merge together to form molecular medicine that seeks to identify the molecular errors that produce disease and to correct them.

October 12, 2004

Z. Hong Zhou
University of Texas Medical School


Streaming Video
  

Seeing Biological Nano-Machineries by Cryo-Electron Microscopy and Tomography
Recent advances have given electron cryomicroscopy and single-particle reconstruction (cryoEM) an increasingly important role in determining subnanometer-resolution structures of macromolecular complexes (>150 kDa / 10 nm). At this resolution, alpha helices and beta sheets are readily recognizable and provide valuable constraints for building atomic models by bioinformatics means. The emerging method of cryo-electron tomography (cryoET) allows the determination of three-dimensional (3D) architectures of objects ranging in size from a nanometer to micrometers. These structural methods provide exciting opportunities to determine the 3D structures of sub-cellular assemblies that are either too large or too heterogeneous to be investigated by conventional crystallographic or NMR methods. ET can also be employed to characterize the 3D structures of other nano-materials, permitting the visualization of the Coulomb potentials of individual atoms. Examples will be presented to illustrate how cryoEM and cryoET structures help in understanding macromolecular functions. First, I will show the state-of-the-art of cryoEM and present a near atomic resolution 3D structure of a dsRNA virus, cytoplasmic polyhedrosis virus and efforts in building an atomic model from this map. This structure reveals a channel along which enzymatic domains are perfectly stacked to provide an efficient mechanism to regulate RNA processing and release. Second, the integrative approach of cryoEM and cryoET is used to study several large, pleomorphic, dynamic structures, including human pyruvate dehydrogenase complex (PDC), human cytomegalovirus (HCMV), and cancer-causing gammaherpesviruses. The variable or dynamic components revealed in these structures are key to their multi-enzymatic functions or activities performed by such supramolecular machineries.

References:

Zhou, Z. H., M. Dougherty, J. Jakana, J. He, F. J. Rixon and W. Chiu (2000) Seeing the herpesvirus capsid at 8.5 ?, Science 288, 877-880.

Zhou, Z. H., H. Zhang, J. Jakana, X.-Y. Lu and J.-Q. Zhang (2003) Cytoplasmic polyhedrosis virus structure at 8 ? by electron cryomicroscopy: structural basis of capsid stability and mRNA processing regulation, Structure 11, 651-663.
October 05, 2004

Jim Heath
Cal Tech
Molecular Electronics & Molecular Mechanics
Abstract:

Very few molecular properties are amenable to study across a broad range of physical environments. One such property is electrochemically driven molecular actuation, and bistable [2]catenanes and [2]rotaxanes provide for ideal molecular systems for investigating this property. These synthetically versatile molecular machines may be incorporated into a number of different environments. Furthermore, the large geometrical and electronic changes that accompany the electrochemically driven molecular motion yield a variety of experimental signatures for quantifying that motion. I will discuss experiments aimed at elucidating the kinetic and thermodynamic parameters of molecular switching in the solution phase, solid-state polymer electrolyte matrices, self-assembled monolayers of electrode surfaces, and molecular switch tunnel junctions. I will then discuss how we have incorporated these molecular mechanical systems into reasonably large-scale circuits (>104 devices), patterned at a device density of 1011 bits/cm2, to demonstrate memory and logic operations.

References:

1. James R. Heath and Mark A. Ratner, "Molecular Electronics", Physics Today May 2003, pp. 43-49.

2. E. Johnston-Halperin, R. A. Beckman, N. A. Melosh, Y. Luo, J. E. Green, and J. R. Heath, "Fabrication of conducting Si nanowire arrays", Journal Of Applied Pysics Vol 96, Num 9, November 1, 2004