Tag Archives: Small Times Magazine

by Laura Peters, contributing editor

IEDM Previews:
Intel fabs highest mobility pFET with Ge channel
University of Tokyo first to demo III-V self-aligned source/drain
IBM, Macronix identify phase-change memory failure mode
Record photodiode quantum efficiency from Taiwan lab
How strain can protect devices from ESD
SEMATECH tipping III-V MOSFET, FinFET, and resistive RAM
TSMC anneal for gate-last HKMG process
Imec IEDM presentations to cover More than Moore, ITRS
When do TSV stresses affect device operation?
Multi-threshold-voltage flexibility in FDSOI
CMOS imager works from light to night
Carbon nanotube vias approach production densities
IBM Alliance simplifies pFET HKMG
IM Flash details 25nm NAND

October 20, 2010 – Researchers will soon report they are close to achieving the density of (CNTs) needed to manufacture carbon nanotube interconnect vias for production applications.

At the upcoming International Electron Devices Meeting (IEDM, 12/6-8 in San Francisco, CA), a group from Grenoble, France-based CEA LITEN and CEA LETI, École Polytechnique Fédérale Lausanne in Switzerland, and the UK’s Cambridge University will present its methods used to achieve vias with a density of 2.5 × 1012 tubes/cm2 — equivalent to 8 × 1012 walls/cm2, nearing the value of 3 × 1013 walls/cm2 required for interconnect vias. This density is an order of magnitude beyond the previous state of the art.

Carbon nanotubes are ideal as interconnect vias because they can carry currents of over 108 A/cm2. However, there are two key challenges preventing CNT incorporation in interconnect vias: reaching the necessary density and having a viable integration scheme. These researchers grew CNTs on metal alloy (99.5% aluminum, 0.5% copper) or polysilicon substrates using an iron catalyst. The AlCu alloy was chosen due to its low resistance at very small linewidths. Using a root-growth method at 580°C, 200mm wafers, and the process flow shown in Figure 1, the result was double- and triple-walled CNTs with via geometries from 250nm to 1μm (Figure 2).

Figure 1. Process flow for CNT fabrication: wet etch is followed by catalyst deposition, CNT growth, encapsulation with Al2O3 by ALD, CMP, then top contact. (Source: CEA/École Polytechnique/Cambridge U.)

To measure the density achieved, the researchers dipped the CNTs in alcohol, yielding a filling factor as high as 64%. The group was also able to measure the density as a function of via diameter, which varied from 5 × 1012 to 8 × 1012 walls/cm2.

Cross-section of a 250nm CNT via on AlCu after CMP. (Source: CEA LITEN)
 High-density CNT growth in 500nm vias on AlCu line. (Source: CEA LITEN)

 

(October 20, 2010) — When NASA wanted to look for water on the moon, it used a MEMS-enabled near-IR portable spectrometer. At the MEMS Technology Summit, Steve Senturia, Professor of Electrical Engineering, Emeritus. MIT, and the former chairman and CTO at Polychromix (purchased by Thermo Fisher Scientific in June 2010), presented details about the Phazir spectrometer NASA used.

Podcast: Download or Play Now

Having just been notified by NASA that results from the 2009 finding will be published in the 10/22/10 issue of Science, Senturia discusses the project in a podcast interview at the MEMS Technology Summit (taking place October 19-20 at Stanford University) with Debra Vogler, senior technical editor.

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(October 20, 2010) — Imec Taiwan signed the co-funding contract with the Taiwanese Ministry of Economic Affairs (MOEA) for its R&D activity Imec Taiwan Innovation Centre (ITIC). ITIC’s goal is to expedite applied research projects with industry and academia that will result in electronic designs, components and technology solutions. The new R&D centre will focus on a variety of innovative applications in bioelectronics, MEMS and "green" electronics that are enabled through 3D system/package co-design and system-level evaluation.

The business plan for ITIC forecasts a growth of its research staff to 40+ over 3 years. ITIC is launched with the signing today of an agreement between imec Taiwan and the Institute for Information Industry (III) on behalf of the Taiwanese MOEA. ITIC is financed by imec Taiwan and will be co-funded by the Taiwanese MOEA as a "Multinational Innovative R&D Centre" under MOEA subsidy for the Project of Encouraging Foreign Enterprise Establishing Research and Development Center in Taiwan. The worldwide impact of the Taiwanese semiconductor and consumer electronics industry is unequivocal, and there is an increasing intention of the stakeholders to move up the value chain by entering key innovation areas, say imec representatives. Consequently, Taiwan is an important market for a nanoelectronics R&D centre such as imec. ITIC, being imec’s local R&D centre in Taiwan, will facilitate and intensify the collaboration between imec and the Taiwanese industry and academia.

"The creation of ITIC, two years after having established a representation office in Hsinchu, Taiwan, is essential in our continued efforts to create value for our current and future partners in Taiwan, to leverage our global partnerships, and to actively interact with the Taiwanese ecosystem," said Luc Van den hove, CEO and president of imec and member of the Board of imec Taiwan. "An R&D initiative such as ITIC will intensify imec’s interaction with the local semiconductor and system-level companies and academia."

"As a semiconductor innovative applications centre, ITIC will support the upward shift in Taiwan’s technology value chain and contribute to the realization of Taiwan’s strategic Innovation Plan. It will accelerate open innovation that will result in locally owned IP in the area of intelligent electronics," says Jung-Chiou Hwang, Vice Minister of Economic Affairs, adding that the imec center might attract foreign (European) investment in Taiwan-based high technology as well.

Imec performs world-leading research in nanoelectronics. Further information on imec can be found at www.imec.be.

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(October 19, 2010 – BUSINESS WIRE) — Scientists at the Naval Research Laboratory (NRL) in conjunction with the Scripps Research Institute in La Jolla, CA, recently reported a detailed study of the interactions of water-soluble semiconductor quantum dots (QDs) with the electro-active neuro-transmitter dopamine. These biocompatible QD-dopamine nano-assemblies may be used as the active component for sensors that are used to detect a wide variety of target analytes ranging from sugars to peroxides.

According to NRL’s Dr. Michael Stewart, a member of the research team, "The nature of the QD-dopamine interaction has been the subject of more than 25 recent research papers that attempted to uncover and exploit the exact nature of how the QDs interact with these small electro-active chemicals during the sensing process. Until now, it remained unclear as to whether dopamine acted as an electron acceptor or as an electron donor to quench luminescence from the QD."

"The chemical state of dopamine changes from a protonated hydroquinone in acidic media to an oxidized quinone in basic environments. A series of carefully designed experiments allowed the research team to establish that only the quinone form is capable of acting as an electron acceptor resulting in quenching of the QD emission. The rate of quinone formation and hence QD quenching is directly proportional to pH and can therefore be used to detect changes in the pH of solutions. Using this nano-scale sensor, the research team was able to demonstrate pH sensing in solution and even visualize changes inside cells as cell cultures underwent drug-induced alkalosis," explained Dr. Scott Trammell. Read more about nanotechnology in the medical sciences.

The interdisciplinary group of scientists involved in this project from NRL include: Dr. Michael Stewart and Dr. Kimihiro Susumu of NRL’s Optical Sciences Division, and Dr. Igor Medintz, Dr. Scott Trammell, and Dr. James Delehanty from NRL’s Center for Bio/Molecular Science and Engineering, along with Professor Phillip Dawson and Dr. Juan B. Blanco-Canosa of the Scripps Research Institute.

This research was supported by NRL’s Nanoscience Institute and the Defense Threat Reduction Agency (DTRA), and is focused on areas tasked to the Department of Defense under the President’s National Nanotechnology Initiative. The research was published in the August 2010 issue of Nature Materials.

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(October 19, 2010) — Francesco Doddo, Roberto Condorelli, Roberto De Nuccio, STMicroelectronics (NYSE:STM), acknowledge the benefits and upsides of solar photovoltaic (PV) installations. However, safety and security concerns have accompanied photovoltaic installations from the start. Among the MEMS applications in the solar market are vibration analysis and anti-theft and include residential inverters, inverters mounted on poles, and solar street lighting. With PV installations on the rise globally, the authors look at various MEMS applications in this renewable energy system.

Vibration analysis for earthquake detection and wind monitoring

When solar PV is located in a seismic zone, earthquake forces must be considered; additionally, oscillations caused by the wind have to be taken in to account when the solar system is located in hurricane zones.

In the case of grid-connected systems (i.e., residential inverters, inverters mounted on poles, solar street lighting), earthquake and hurricane events increase the risks of fire, arc generation, and electrocution. At this time, every solar system should be disconnected from the grid.

In contrast, for off-grid systems such as battery-powered solar LED street lights, during an earthquake, the solar LED should be turned on with maximum power — working as emergency lights to ensure a population’s safety and avoid panic. In both cases, MEMS accelerometers are an efficient tool to monitor the solar panel vibrations due to wind or to earthquakes.

 
Figure 1. a) FFT analysis; and b) instantaneous accelerations plot. 

Figure 1 contains photos taken using the graphical user interface (GUI) of an evaluation board that features a 3-axis ±8g smart digital accelerometer. Figures 1 and 2 show the fast-Fourier transform (FFT) calculation and the instantaneous accelerations plot along the three axes of the accelerometer [1,2]. Combining the interrupt functionalities, the sleep-to-wake and the low-power mode allows the application to have a fast and efficient vibration detection and vibration analysis.

 
Figure 2. A STEVAL-MKI022V1 evaluations board.

In a typical vibration analysis application, the digital accelerometer may be configured to work in low-power mode and generate an inertial wake-up interrupt signal accordingly to a programmed acceleration event along the enabled axes. Thanks to the sleep-to-wake function in conjunction with the low-power mode, the device, even if asleep, continues sensing acceleration and generating interrupt requests.

When the acceleration on one of the axes overcomes a user-programmed threshold, the sleep-to-wake function is activated, and the accelerometer is able to automatically wake-up as soon as the interrupt event has been detected, increasing the output data rate and bandwidth. With this feature, the system may be efficiently switched from low-power mode to full performance depending on user-selectable positioning and acceleration events, thus ensuring power saving and flexibility. Depending on the level of complexity requested by the application, the acceleration data can be sent to a host microcontroller (i.e., 32bit STM32L or 8bit STM8L low power ST MCUs) through the on-board SPI interface.

Tilt detection for anti-theft or safe maintenance

When solar installations are located in remote places — solar pole installations, solar farms — an anti-theft system is useful to avoid the risk of theft. MEMS accelerometers can be used for tilt detection to detect a change in the installation angle. In a similar way, tilt detection can help users understand if the solar panel has been removed from its original location (i.e., for maintenance); this information can be used to put the system in a safe condition, i.e., trough electronic switch off the line (Fig. 3).

 
Figure 3. a) Tilt measurement; b and c) the installation angle change during a theft or maintenance action.

The accelerometer measures the gravity vector projection on the sensing axis. The amplitude of the sensed acceleration changes as the sine of the angle α between the sensitive axis and the horizontal plane. With a 3-axis accelerometer, the user can use the Z axis to combine with the X and Y axes for tilt sensing, to improve tilt sensitivity and accuracy over 360° of rotation (Fig. 4) [3].

 

 
Figure 4. Tilt sensitivity of a 3-axis accelerometer, and b/c) an example of tilt sensing using an evaluation board that uses a 3-axis accelerometer, and the associated GUI.

References:
1. ST Microelectronics’ MEMS Website page: http://www.st.com/mems
2. MEMS Evalboards: http://www.st.com/stonline/products/families/evaluation_boards/steval-mki022v1.htm
3. Tilt measurement Application Note: http://www.st.com/stonline/products/literature/an/17289.pdf

Francesco Doddo holds a degree from Università degli Studi di Messina and is market development engineer at STMicroelectronics, Lexington, Massachusetts, USA, www.st.com. The article was co-authored by Roberto Condorelli and Roberto De Nuccio, also of STMicroelectronics.

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(October 18, 2010) — Rice University research that capitalizes on the wide-ranging capabilities of graphene could lead to circuit applications that are far more compact and versatile than what is now feasible with silicon-based technologies.

Triple-mode, single-transistor amplifiers based on graphene — the one-atom-thick form of carbon that recently won its discoverers a Nobel Prize — could become key components in future electronic circuits. The discovery by Rice researchers was reported this week in the online journal ACS Nano. 

Top left: A graphene transistor with source and drain electrodes; top right, a schematic for the triple-mode single-transistor graphene amplifier; and bottom, a graph showing the three distinct modes of operation. (Images: Mohanram Lab/Rice University)

Graphene is very strong, nearly transparent, and conducts electricity very well. But another key property is ambipolarity, graphene’s ability to switch between using positive and negative carriers on the fly depending on the input signal. Traditional silicon transistors usually use one or the other type of carrier, which is determined during fabrication.

A three-terminal single-transistor amplifier made of graphene can be changed during operation to any of three modes at any time using carriers that are positive, negative or both, providing opportunities that are not possible with traditional single-transistor architectures, said Kartik Mohanram, an assistant professor of electrical and computer engineering at Rice. He collaborated on the research with Alexander Balandin, a professor of electrical engineering at the University of California, Riverside, and their students Xuebei Yang (at Rice) and Guanxiong Liu (at Riverside).

Mohanram likened the new transistor’s abilities to that of a water tap. "Turn it on and the water flows," he said. "Turn it off and the water stops. That’s what a traditional transistor does. It’s a unipolar device — it only opens and closes in one direction. But if you close a tap too much, it opens again and water flows. That’s what ambipolarity is — current can flow when you open the transistor in either direction about a point of minimum conduction." That alone means a graphene transistor can be "n-type" (negative) or "p-type" (positive), depending on whether the carrier originates from the source or drain terminals (which are effectively interchangeable). A third function appears when the input from each carrier is equal: The transistor becomes a frequency multiplier. By combining the three modes, the Rice-Riverside team demonstrated such common signaling schemes as phase and frequency shift keying for wireless and audio applications.

"Our work, and that of others, that focuses on the applications of ambipolarity complements efforts to make a better transistor with graphene," Mohanram said. "It promises more functionality." The research demonstrated that a single graphene transistor could potentially replace many in a typical integrated circuit, he said. Graphene’s superior material properties and relative compatibility with silicon-based manufacturing should allow for integration of such circuits in the future, he added.

Technological roadblocks need to be overcome, Mohanram said. Such fabrication steps as dielectric deposition and making contacts "wind up disturbing the lattice, scratching it and introducing defects. That immediately degrades its performance (limiting signal gain), so we have to exercise a lot of care in fabrication. "But the technology will mature, since so many research groups are working hard to address these challenges," he said.

The National Science Foundation and the DARPA-Semiconductor Research Corporation’s Focus Center Research Program supported the work. Read the abstract at http://pubs.acs.org/doi/abs/10.1021/nn1021583

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(October 18, 2010) — Thermo Fisher Scientific Inc., part of Thermo Fisher Scientific Inc. (NYSE: TMO), launched a new version of the Thermo Scientific K-Alpha X-ray photoelectron spectrometer (XPS). This fully integrated surface characterization tool is designed for research and development of new surface chemistries as well as dealing with routine characterization of surfaces, thin films and coatings.

The original K-Alpha was designed to offer scientists and engineers a new XPS solution by offering unprecedented ease of operation, and a streamlined workflow via the Thermo Scientific Avantage data system. The latest revision of the K-Alpha platform features improved spectroscopic performance, delivering increased countrates, faster analysis times and improved chemical detection. Further enhancements include improvements to the unique sample viewing system, better automation, and a new glove box option for handling air-sensitive samples.

The new instrument integrates premier spectrometer performance with the latest version of the Thermo Scientific Avantage XPS acquisition and processing user interface. This combination of instrumentation and software combines high sample throughput with market leading analytical performance, essential for tackling the complex materials characterization needs of today’s surface analysis applications. The high level of integration between hardware and software enables users to calibrate their instrument with a single button press and incorporates full traceability of all system parameters.

The Avantage Data System is designed to offer exceptional levels of productivity via an optimized workflow that guides analysts through data acquisition, interpretation, processing and report generation. Avantage offers full digital tool control while providing a comprehensive range of XPS spectrum and image processing routines. Customized laboratory reporting templates allow analysis reports to be easily exported to standard PC applications, such as Microsoft® Office, at the click of a mouse. The new Avantage Indexer (AI) system allows quick and easy management of all stored data sets, allowing management by element, chemistry, acquisition date and other important parameters.

Thermo Scientific K-Alpha enables significant progress in the area of materials analysis. Improved performance and new software features in the upgraded instrument will enable progress in surface characterization,” said Mike Jost, vice president and general manager of molecular spectroscopy and surface analysis and microanalysis for Thermo Fisher Scientific.

The Thermo Scientific K-Alpha will be unveiled at booth 217 at the AVS 57 International Symposium and Exhibition 2010, October 17-22, Albuquerque, NM.

Thermo Scientific is part of Thermo Fisher Scientific Inc. (NYSE: TMO). For more information, visit www.thermofisher.com. For information on this product, visit  www.thermoscientific.com/surfaceanalysis.

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(October 18, 2010) — Scientists at the U.S. Defense Advanced Research Projects Agency (DARPA) in Arlington, VA, are asking industry to develop a miniature, power-efficient inertial navigation and guidance device that combines precision timing and inertial measurement on one chip for applications like personal navigation, unmanned aerial vehicles (UAVs), unmanned underwater vehicles (UUVs), and compact munitions.

DARPA issued a broad agency announcement (DARPA-BAA-11-10) Friday for the Single Chip Timing and Inertial Measurement Unit (TIMU) program to address key challenges and potential benefits of developing microscale components for advanced precision navigation, guidance, and control for military systems. The focus is on a single-chip, self-contained system that provides precise timing, location, and orientation information.

The TIMU program seeks to help fill precision military navigation and guidance needs during periods when Global Positioning System (GPS) satellite navigation capability is not available. DARPA officials say miniaturizing timing and inertial measurement units is the only way to enable navigation, guidance, and control (NG&C) on miniature platforms.

Current inertial navigation systems, they explain, do not meet the performance and size, weight, power, and cost (SWaP+C) requirements for many emerging U.S. Department of Defense (DOD) applications, including those needed for personal navigation, unmanned air/underwater vehicles, and compact munitions. Today’s devices that combine timing and inertial measurement units are still bulky, power-hungry, and expensive.

The primary goal of the DARPA TIMU program finding ways to develop a self-sufficient navigation system no larger than 10 cubic millimeters that operates on 200 milliwatts or less, and drifts less than one nautical mile per hour. DARPA scientists are interested in innovative manufacturing and advanced architectures that integrate timing and inertial measurement units.

Ultimately, DARPA officials want to develop a high-yield process for batch manufacturing of high-performance TIMUs that operate in harsh military environments; develop modeling tools to develop individual components, sensor array, and packaging for single-chip TIMUs; demonstrate a TIMU design with reduced power and improved accuracy in measurements of time, position, and orientation; and demonstrate a “black box” level performance for a TIMU that measures timing, position, and orientation in harsh military environments.

Developing all necessary components of a chip-scale TIMU in a small volume will require some major redesign of individual components and innovation in integration. This program focuses on integration-by-design of clocks and inertial sensors on a single-chip TIMU through wafer-level fabrication and packaging, efficient predictive modeling tools, new architectural designs, and systems integration.

Companies interested in participating in the should submit proposal abstracts to DARPA no later than noon eastern time on 24 Nov. 2010. Full proposals are due 25 Jan. 2010. DARPA officials say they expect to award several contracts for this project.

For questions or concerns, contact the DARPA TIMU program manager, Dr. Andrei Shkel, by phone at 703-351-8468, by e-mail at [email protected], by fax at 703-812-5051, or by post at DARPA/MTO, ATTN: DARPA-BAA-11-10, 3701 North Fairfax Drive, Arlington, Va. 22203-1714.

More information is online at http://www.fbodaily.com/archive/2010/10-October/17-Oct-2010/FBO-02311664.htm.

Posted by John Keller, Military & Aerospace Electronics

(October 15, 2010) — Micro electro mechanical systems (MEMS) are perceived as being simple mechanical devices manufactured on 6-inch or smaller wafers, via mature semiconductor fab technology. Recently, MEMS devices have experienced high growth rates in consumer products, and the MEMS potential extends into safety and automotive apps. Semico’s bloggers Joanne Itow and Tony Massimini say foundries and EDA/IP vendors are salivating over the revenue growth potential for MEMS development.

In their latest blog post, Itow, managing director; and Massimini, chief of technology at Semico, say that MEMS are the current "fab filler," just as CMOS image sensors were in 2003. But with applications across the total spectrum of electronics — from screen rotation on cell phones to safety sensors on industrial transportation — MEMS have the potential to be more.

Read the blog for more MEMS analysis and information about Coventor’s latest EDA tool partnership with Cadence: http://www.mapmodel.com/index.php/2010/10/12/mems-small-moves-result-in-big-potential/ 

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(October 14, 2010) — The California Institute of Technology (Caltech) and CEA-Leti, co-founders of the NanoVLSI Alliance, have launched the NanoSystems Partnership Program (NSyP) to accelerate delivery of nanosystems-based innovations to the market.

The partnership, open to new members, already includes four companies from a variety of industries that will enable close collaboration between the alliance and the private sector: AREVA, LECO, bioMérieux and Total.

The partnership is opening new application opportunities, initially based on its nanoelectromechanical systems (NEMS) platform, focusing on three main areas:

  • High sensitivity gas-phase chemical-sensing systems, including preanalytical and chemical separation modules
  • Highly-multiplexed, microfluidic-interfaced mass spectrometry, and
  • Liquid-phase biochemical sensors for pharmaceutical research and point-of-care diagnostics.

Roadmaps establish the staging of prototype demonstrators, beginning with a multichannel gas chromatography detection module, to be realized in the near future.

CEA is a French research and technology public organization, with activities in four main areas: energy, information technologies, healthcare technologies and defence and security. Within CEA, the Laboratory for Electronics & Information Technology (CEA-Leti) works with companies to increase their competitiveness through technological innovation and transfers. CEA-Leti is focused on micro and nanotechnologies and their applications. For more information about Leti, please visit www.leti.fr.

Caltech is recognized for its highly select student body of 900 undergraduates and 1,200 graduate students, and for its outstanding faculty. In addition to its prestigious on-campus research programs, Caltech operates the Jet Propulsion Laboratory (JPL), the W. M. Keck Observatory in Mauna Kea, the Palomar Observatory, and the Laser Interferometer Gravitational-Wave Observatory (LIGO). Caltech is a private university in Pasadena, California. For more information, visit http://www.caltech.edu.

For the past three years, Caltech’s Kavli Nanoscience Institute (KNI) and CEA-Leti’s Electronics and Information Technologies Laboratory have joined their fundamental and technological research expertise through the NanoVLSI Alliance (www.nanovlsi.com) to transition from the era of “nanocraft” to very-large-scale integration of nanosystems. Researchers from both institutions are collaborating to transform nanotechnology-based prototypes into robust, complex sensing systems ready for transfer to industry. Caltech and Leti are sponsoring a November 2 workshop on Caltech’s campus in Pasadena, CA, to discuss the NanoVLSi Alliance’s work, including presentations by members of the NanoSystems Partnership Program. Participants also will have the opportunity to meet with key experts from the alliance and learn about highlights from its technology roadmaps. For more information on the workshop, contact Ariel Cao: [email protected].

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