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MRS Meeting Scene
Day 1 — Monday, April 17, 2006
Daily dose from San Francisco. Bringing you the very best of MRS.
Welcome to San Francisco and the 2006 MRS Spring Meeting!
Nine tutorials conducted during the day marked the beginning of the 2006 MRS Spring Meeting. Tutorials on thin-film Si for large area/flexible electronics, interconnects, nonvolatile memories, and nanophased metal-oxide semiconductors for sensing applications were conducted all day. The afternoon saw tutorials on transistor scaling, negative refractive-index materials, textiles and fabrics with built-in sensing capabilities, solid state lighting, and computation/measurement techniques for hydrogen storage materials. Symposium W on colloids was the first at the meeting to start their sessions; most symposia begin sessions on Tuesday. The other major event of the day was the Student Mixer held in the evening allowing student attendees to meet and network.
Quote of the Day
"Energy is the single most important problem facing humanity today."
- Richard Smalley, Late Nobel Laureate
Tutorial: Thin Film Si Materials and Devices for Large-Area and Flexible Electronics
The tutorial on thin-film Si materials for large-area/flexible electronics, held as part of symposium A, was presented by Friedhelm Finger (Forschungszentrum Jülich, Germany) and Michio Kondo (National Institute of Advanced Industrial Science and Technology, Japan). Hydrogenated amorphous silicon (a-Si:H), nano- /micro-crystalline silicon (nc-Si/µc-Si:H), and polycrystalline silicon (poly-Si) are the thin-film semiconductors used for large-area electronics. The field of large area electronics is seeing a major growth spurt similar to microelectronics in the early 1990s and is expected to grow at a rapid pace in the near term.
Courtesy: Solar Integrated Technologies GmbH
During the morning session, Finger gave an overview on Si thin film materials and applications and described the properties of Si thin films. Currently, amorphous and microcrystalline Si can be directly deposited on large area substrates. Plasma-enhanced CVD (PECVD) is the dominant technique used, and there are challenges of achieving high growth rates as well as uniform thickness over large-areas. There are also numerous challenges in substrate handling, mask alignment, using various types of susbstrates etc. Kondo then presented various methods for the preparation of Si materials including details on PECVD, process control and diagnostics, and crystallization of a-Si to poly-Si, in particular low temperature poly-Si or LTPS, with the goal of forming large-grain poly-Si.
In the afternoon session, various applications and devices were covered. solar cells were first discussed by Finger, followed by thin film transistors, displays, and miscellaneous materials and devices all described by Kondo. Some representative areas discussed are the use of a-Si:H in active matrix technology for displays and imagers, microelectro-mechanical systems (MEMS), microfluidics, bioengineering, and magnetoelectronics. Kondo and Finger concluded the tutorial by giving a broad outlook for the use of Si for large-area electronics. The various research and development efforts currently under way make it clear that a new industry is taking shape around thin-film Si.
Tutorial: Integrating Sensing Capabilities with Textiles and Fabrics
As part of symposium S on Smart Nanotextiles, a tutorial on integrating sensing capabilities into fabrics and textiles was presented in an afternoon session by Gordon Wallace (Univ. Wollongong, Australia), Shirley Coyle, Dermot Diamond and Yanzhe Wu (all from Dublin City University, Ireland). Coyle and Wallace began with a series of introductions to conducting textiles and fibers, including structure and properties, as well as data transmission energy requirements. Wallace discussed the integration of electronic polymers into textiles using different methods, as well as the use and integration of conductive carbon nanotube fibers. He described one specific application, the knee sleeve, for direct bio-feedback. Knee injuries are commonplace in the Australian Football League, and the sleeve was developed to provide instantaneous, individualized and meaningful biofeedback to pre-detect potential injuries to the knee in players, while simultaneously not impeding their movement.
Courtesy: University of Wollongong
In the next session, the presenters from Dublin City University overviewed interconnect, data transmission and energy requirements, as well as selected applications. Various possibilities for integrating chemical sensing, pH sensing, and optical sensing were discussed. There are power issues and data transmission issues to be considered. In the healthcare field, wearable sensors can play a major role. Various potential applications of wearable sensors were described including biosensors for sports applications, for monitoring childhood obesity, for monitoring diabetes, wound healing, and sweat analysis for diagnostics. An interesting application described was a "smart shirt" for monitoring breathing which could be useful in sleep apnea studies, infant breathing and sports applications, wherein the shirt constantly monitors breathing volume. Another fascinating application is a smart chair which has smart foam inserted into the back support of the chair. This can be used to monitor the position of a person sitting on it and can also measure skin response and the heart rate. This could be used for personalized healthcare as well as for ergonomics.
Tutorial: The Transistor Scaling Dilemma?
What do materials researchers do when making transistors smaller no longer results in performance benefits? Scott E. Thompson and Kevin S. Jones of the University of Florida, and Byoung Hun Lee of SEMATECH (IBM) discussed three of the possibilities in the tutorial which formed part of symposia C, D, E on the “Transistor Scaling Dilemma” today.
Thompson, speaking on the “Future of CMOS,” touted the long run that silicon has had as the leading material in the transistor field, and let it be known that it is too soon to sound the death knell on this technology. “Gazing into the crystal ball,” he said, “silicon technology is and will continue to be the driver of the information age.” While he conceded that the era of simple CMOS scaling is over, there is enormous life left in planar CMOS. Feature-enhanced CMOS is the next big thing; non-silicon devices are unlikely to compete for at least thirty years in his opinion. Focusing mainly on the benefits of strained silicon technology, which alters the band structure and increases the carrier mobility in the transistor, Thompson noted that mobility has increased by 90% in PMOS devices using Intel 2nd generation strained silicon at the 65 nm node. By integrating new materials such as carbon nanotubes and silicon nanowires into the mix, silicon could possibly be used as far down as the 11 nm node.
Lee discussed the use of high dielectric constant materials and metal gates in transistors in his presentation entitled “Advances and Challenges in Gate Stack Technology for Nanoscale CMOS Devices.” His company SEMATECH began its high dielectric constant research program in 1997 focusing on BST, TiO2, and Ta2O5; they extended the materials to ZrO2, HfO2, and HfSiOx in 1998, and TaN/HfO2 in 2000. Roadblocks in high-k/metal gate implementation include:
o Mobility degradation
o Threshold voltage (Vth) control and stability
o Electrode material identification
o Integration complexity
o Unknown reliability mechanisms
The secret to scaling a high dielectric constant stack is in maximizing the polarizabilty or minimizing the molar volume of the materials, he said. Lee devoted much of his talk to the large discrepancy in reported values of the work functions of similar metals by different research groups. These scattered results make it difficult to choose metals for gates in transistor devices. He presented a solution based on using the real metal/dielectric barrier height for the measurement. The gate material and the high dielectric constant material must be optimized together, according to Lee. Hf-based dielectrics may help in achieving the 22 nm node, but will probably not be useful at lower nodes.
Jones concluded the tutorial with a presentation on “Ultra-Shallow Junctions,” which included a discussion of flash annealing (1.3 ms anneals up to 1400°C) and non-melt laser processing (0.2-1.8 ms anneals up to 1400°C). The goals of his research are to maximize boron at substitutional sites, minimize diffusion to reduce source/drain overlap, and ultimately to lower spreading resistance.
Tutorial: Science and Technology of Nonvolatile Memories
Tutorial G on the Science and Technology of Nonvolatile Memories featured four prominent speakers and four widely varied non-volatile memory (NVM) technologies. Dirk J. Wouters of IMEC in Belgium discussed Ferroelectric Random Access Memories (FeRAM); Ilan Bloom of Saifun Semiconductors Ltd. of Israel talked about Nitride-based ROM (NROM) technology; Agostino Pirovano of STMicroelectronics in Italy dealt with Phase-Change Memory (PCM); and Greg Grynkewich of Freescale Semiconductor, Inc. explored Magnetoresistive Random Access Memory (MRAM).
Wouters led off the tutorial with his presentation entitled “The Science and Technology of Ferroelectric Random Access Memories,” in which he discussed the basic physics of the devices, their status in the matrix of memory technologies, and strategies for integrating them with other devices. FeRAM is based on spontaneous electric polarization that can be reversed or reoriented. The basic device is the capacitor. The most important materials currently in use are multi-metal oxides with perovskite substructures, including lead zirconate titanate (PZT), strontium bismuth tantalite (SBT), and lanthanum-substituted bismuth titanate (BLT). While each of the three have their advantages, PZT currently dominates scaled technologies due to its relatively low formation temperature of 610-620°C. The low voltage operation, low power requirements, and fast switching capabilities of FeRAM makes it an ideal memory choice for contactless smartcards and ID tags, portable and battery operated systems, and ultralow power applications. Wouters concluded that while FeRAM is promising, there is still much work to be done: the complexity of the manufacturing process has positioned FERAM two to three generations behind standard technology on the ITRS roadmap.
The nitride-based ROM (NROM) technology depends upon and oxide-nitride-oxide stack, and features two or four separate bits in a cell, according to Bloom. The nitride middle layer is Si3N4, with the bottom oxide layer formed by standard thermal oxidation and the top oxide by a combination of high temperature oxide deposition and high temperature wet oxidation. A cell is written to (programmed) via channel hot electron injection, and erased by tunnel enhanced hot hole injection. NROM exhibits excellent scalability, with a theoretical physical limit of 3 nm. NROM technology involves no exotic materials or processing steps, so it integrates easily with other devices. The technology is currently in its sixth generation of production.
Pirovano made a bold statement in the title of his presentation: “Phase-Change Memory: A Bet to Win the Future Challenges.” PCM has been around since the 1970s, and has made large strides since the 1990s in DVD-RW and CD-RW memory storage devices. It is currently the technology behind FLASH memory, which now has a $15 billion dollar market. PCM materials are alloys containing one or more group VI (chalcogenide) elements, which exhibit reversible transition between disordered and ordered atomic structure. Ge2Sb2Te5 (GST) is often used. The amorphous and poly-crystalline phases of the PCM store data by representing binary ones and zeros. The reading mechanism is the resistance change of the GST, while the writing mechanism is self-heating due to current flow. FLASH cell scaling challenges include tunnel oxide thickness, interpoly dielectric thickness, cell gate length, and contact dimension/ isolation spacing. Pirovano said that “superior performance, good scalability, fair cost, and easy embedability make PCM a good candidate to eventually become a mainstream NVM.”
Finally, Grynkewich made the case for Magnetoresistive RAM devices, in which information is stored as magnetic polarization, not charge, and is detected as a change in resistance. Magnetic tunnel junction (MTJ) MRAM devices consist of two conducting magnetic layers separated by a quantum mechanical tunnel barrier; the relative orientation of the magnetic polarization of the two layers affects the resistance to current flowing through the barrier. The device comprises a complicated stack of materials with very thin layers, so excellent process control is a must. The layers include a tantalum top electrode, followed by NiFe, CoFe, or CoFeB. The tunnel barrier is currently AlOx. Next comes another layer of NiFe, CoFe or CoFeB, followed by a PtMn alloy, and finally a bottom tantalum electrode. MRAM advantages include nonvolatile data retention of greater than 10 years; fast, symmetrical read/write processes of 25-35 ns for 4 Mb at the 0.18 micron technology node; and unlimited endurance as evidenced by greater than 1016 cycles of non-destructive read operation. New materials and processes expected to extend the scalability of MRAM include MgO as a tunnel barrier and spin momentum transfer.
Tutorial: Light-Emitting Diodes and Solid-State Lighting
E. Fred Schubert (Rensselaer Polytechnic Inst.) presented tutorial DD on Light-Emitting Diodes and Solid-State Lighting. He kicked off the session quoting the late Nobel Laureate Richard Smalley, who said, “Energy is the single most important problem facing humanity today” and “conservation efforts will help the worldwide energy situation.” LEDs are already found in applications from displays to car headlights, and they show much greater efficiency than incandescent or even fluorescent bulbs. Schubert's coverage focused on inorganic materials, particularly III-V double heterostructures. Some key issues discussed included examining the competing processes of radiative and nonradiative recombination, citing the importance of eliminating deep level defects caused by impurities. He also described the variety of efficiencies to be considered: internal, extractive, external, and power efficiencies, and gave examples of how to control these efficiencies. See www.LightEmittingDiodes.org for more information.
Upcoming: Materials Research Initiatives from a Global Policy Perspective
Thursday, April 20
Time: 6:00 p.m. - 8:00 p.m.
Golden Gate A, San Francisco Marriott
Panel Chairs/Moderators:
- William Spencer
CEO Emeritus SEMATECH
- Kenneth Flamm
Professor & Dean Rusk Chair in International Affairs University of Texas at Austin
The panel on materials research initiatives from a global policy perspective will review current and planned initiatives underway in materials research in selected regions of the world, assessing the role of those initiatives in improving both academic science and industrial capabilities in those regions. Leading scientists and engineers will broadly summarize the state of materials technology development in their regions. Panel participants will provide an overview of national and regional initiatives from a global perspective, as well as insight into the state of materials technology development in parts of Europe, Asia, and the United States. Discussion and questions will focus on relationships between materials research and industrial performance in various high-tech industries.
Panelists include:
- Michael Moloney
Overview: National and Regional Initiatives from a Global Perspective
Study Director, Globalization of Materials Research and Development
National Materials Advisory Board
The National Academies
- Marie-Isabelle Baraton
State of Materials Technology Development in Europe
Senior Scientist, Université de Limoges
Limoges, France
- Karlheinz Bock
Deputy Director, Fraunhofer Institute for Reliability and Microintegration - Munich Branch
Munich, Germany
- Hideomi Koinuma
State of Materials Technology Development in Asia
Vice President, National Institute for Materials Science
Tsukuba, Japan
- Julia Phillips
State of Materials Technology Development in the U.S.
Director, Physical, Chemical and Nano Sciences Center
Sandia National Laboratories
Entrepreneurship Challenge
Tuesday, April 18
Time: 5:00 p.m.
Pacific A - Marriott Hotel
The MRS Entrepreneurship Challenge is a competition designed to help our members develop the entrepreneurial skills that get ideas out of the lab and directly into the marketplace. Come see the final round of the MRS Entrepreneurship Challenge! The top three teams were chosen from a panel of judges within the venture capital community to present their business plans as they compete for the $3000 grand prize. Research Collaboration Center
Looking for collaborators for your research or an opportunity to collaborate with others based on your expertise? The Research Collaboration Center is your answer. Download the RCC form and post your research interests, your expertise or requirements for potential research collaborations at the Research Collaboration Center set-up at the Moscone West Convention Center near the registration area. This information can subsequently be posted on the MRS Website, if you wish, after the Spring Meeting. Just check the appropriate box in the form.
Exhibit Experience
ATC ORION Series Sputtering System: Compact, Powerful UHV Sputter Tool
AJA International, Inc. introduces the highly versatile, compact  ATC ORION Series Sputtering System which inherits many design features from the popular, highly evolved ATC Series Sputtering tools and offer some unique features designed to optimize deposition uniformity. Three, four and five gun versions have been delivered with load-locks, high temperature substrate heaters and computer control. Economical HV versions are also available. Visit Booth 404 for additional information or contact us at topgun@ajaint.com or http://www.ajaint.com.
Ambios Technology Adds AFM/SPM Products by Acquisition of Quesant Instruments
Ambios Technology recently announced the acquisition of Quesant Instruments and  its scanning probe microscope product line. As part of the acquisition, multiple patents related to some of the most fundamental operating principles of scanning probe microscopy, including Quesant's patented isotopic focal system, are assigned to Ambios. The addition of the Q-scope SPMs expands Ambios' product offering of high resolution stylus and optical surface profiling systems for the academic and industrial research markets. Visit Ambios at Booth 321, or contact us at info@ambiostech.com or www.ambiostech.com.
New NanoIndentation Module for the MFP-3D AFM
Now, true quantitative AFM measurements for nanoindenting applications are  possible with the new NanoIndenter for the Asylum Research MFP-3D AFM. The NanoIndenter bridges the gap between conventional indenters and AFM cantilever indenters. The NanoIndenter drives the nanoindenting tip perpendicular to the sample. Displacement and force are then measured with a combination of the MFP-3D AFM’s optical detector and the patent-pending NPS™ Nanopositioning sensors. This combination results in exquisite force and positioning sensitivity for manipulation and lithography, repeatable imaging, accurate imaging offsets, precision force curves, and quantitative feature measurement. See a demonstration at Asylum Research Booth 310 or visit http://www.asylumresearch.com. Rapid Thermal Processor from AXIC Inc.
AS-Micro is a two-inch rapid thermal processor from AXIC, Inc. dedicated to research  applications. The system has a temperature range from room temperature to 1,200ºC, ramp rate up to 250ºC/s, gas mixing capability with MFCs, and vacuum range from atmosphere to 10-3 torr. The system is provided with full PC control with Windows-compatible software for editing recipes and process data logging. For more information, please stop by Booth 532, visit our website at www.axic.com or contact us at info@axic.com.
Bruker AXS Introduces D8 SCREENLAB™--Combined XRD and Raman High-Throughput Screening
Bruker AXS Inc. recently introduced its new D8 SCREENLAB™, a screening system  which combines the analytical power of two-dimensional X-ray diffraction (XRD2) and Raman spectroscopy. The D8 SCREENLAB integrates the Bruker AXS D8 DISCOVER XRD2 system for combinatorial materials screening with the Bruker Optics Raman probe into one combined advanced materials discovery solution. In the D8 SCREENLAB, the X-ray source, optics and unique 2D X-ray detector, as well as the laser source, the Raman probe and an auto-zoomed video microscope are all integrated into one single platform. As a result, the X-ray diffraction pattern and the Raman spectrum as well as the optical image from the same sample can be obtained in one sample run from a materials library. Stop by Booth 506 for additional information or contact us at http://www.bruker-axs.com.
The Dimatix Materials Printer enables high-performance micro-precision deposition of  a wide range of “inks” tailor fit to specific applications. It is the industry's first low-cost, cartridge-based piezo ink jet printing system that directly deposits fluids for proprietary research allowing faster and less expensive product development. The MEMS-based ink jet head coupled to a disposable cartridge allows researchers to deposit the materials they have synthesized today. Visit Dimatix at Booth 334 or e-mail info@dimatix.com to learn more.
Ecopia Spring Clip Board for Use with the HMS-3000 Hall Effect Measurement System
The Spring Clip Board allows samples to be mounted in the Ecopia HMS-3000 Hall Effect Measurement System  without the need to use bonding wires. Contacts often must still be made, but the spring loaded pins allow for easier sample mounting without the use of wires. For use with the HMS-3000 0.55 Tesla magnet kit. For additional information, visit Booth 223 or contact Larry Bridge at 480-988-2256 or Larry@bridgetec.com.
First Nano is pleased to announce the introduction of three new products and the Open Lab. The EasyTube  2000/3000/4000 process development platforms lead the way in optimized nanomaterials synthesis using various CVD techniques. The Open Lab gives researchers unprecedented access to equipment, processes, and capabilities. With over 24 years of industry experience and the largest install base, no other company has the experience and knowledge in nanotube and nanowire growth. Come visit Booth 315 to find out more or contact us at cary.chee@firstnano.com or http://www.firstnano.com.
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