The 1998 spring meeting got off to a good start, with a number of symposia commencing their schedules. The highlight of the day was the plenary session in the evening which included the awards presentations. The Outstanding Young Investigator award was presented to Dr. Anne Mayes of MIT. Earlier in the evening, Dr. Mayes presented her OYI talk "Tailoring polymer surfaces for controlled cell behavior" in symposium CC, which is described below. Six graduate student awards were also presented, selected from 15 finalists. The six graduate student awards went to Carlo Waldfried, Hao Lee, Jay J. Senkevich, Mihail N. Popescu, Yunfeng Lu and George B. Palmer (please see below for details). The finalists gave short presentations based on their work earlier in the day. The high quality of the research was evident from these talks. In addition, the Spring Meeting Chairs John Emerson, Ron Gibala, Caroline Ross and Leo Schowalter were recognized by the President of MRS, Bob Nemanich.

The plenary speaker was Dr. John P. Lockwood, a Volcanologist, who gave an outstanding presentation on "Volcanoes: The Ultimate Materials Source". The theme of his talk was that the source of chemical elements found on the surface of the earth are volcanoes, which bring up subterrestrial elements. He also described his work with volcanoes all over the world, and showed several photographs of erupting volcanoes. He pointed out that there are mainly two types of volcanoes, red volcanoes spewing out lava, and the grey volcanoes, typically conical ones, do not actually have a lava flow but have high temperature incandescent rocks and ash coming out. Dr. Lockwood described current efforts to control lava flow and also talked about prediction of impending volcanic eruptions. One of his interesting recent projects was as consultant to the movie "Dante's Peak". He showed a couple of clips from the movie and talked about how the movie was made. He also indicated that in general the movie was realistic in terms of Volcanic science. The talk was greatly appreciated by the audience.

Anne Mayes (professor in the Department of Materials Science and Engineering at MIT), as recipient of the Outstanding Young Investigator award, gave a presentation on "Tailoring Polymer Surfaces for Controlled Cell Behavior" to an overflowing room. Polymer "scaffolds" are being developed, for example, to direct cell adhesion to regenerate organs. The polymer surface needs to prevent protein from infiltrating it causing bad cell interaction, while tethered end-chains need to attract the appropriate signaling molecules. Taking a materials scientist's viewpoint she described how two types of polymers, linear and star polymers, affect surface coverage and cell adhesion. She reported several of her student's finding including that star-shaped polymers, if they have many arms, gain in end functionality, but can create traps for proteins. Looking both at self-consistent field calculations and experimental results, the best approach is described as a self-assembled blend of linear and star polymers to further control the surface behavior. Additional modifications can further improve protein resistance.

Several symposia started their program with invited review talks by experts in the respective fields. Symposium I (Advanced interconnects and contact materials and processes for future ICs) started with a talk by Dr. James Meindl of Georgia Tech on Interconnection limits on 21st century gigascale integration. He divided the limitations on Interconnects into theoretical and practical considerations listing fundamental limits, material limits, device limits, circuit limits and system limits. He suggested that from 0.25 micron technology at present we could touch 0.03125 microns technology in thirty years or so with improvements in current manufacturing technologies. Further improvements would require radical new architectures. One important consideration would be to keep interconnects short, was his message. While the trend of exponential growth of interconnect integration continues, it can't last forever, or so it has been said, and this paper outlined fundamental, material, device, circuit, and systems limits imposed by theoretical and practical considerations. The systems level presents the most numerous, nebulous, and restrictive limits, while materials limits present challenges relating to switching energy, transit time, thermal conduction, and time-of-flight The big question then is what technology in the next 5-8 years will take us beyond the 100 nm microlithography limit?

Within Symposium I, one of the important topics covered was Copper interconnect technology. Edelstein from IBM gave an overview on Copper ULSI interconnects. Copper lends itself to heirarchical wiring and has several advantages over Cu-Al currently used, including performance, reliability and cost. IBM has developed a prototype 32-bit RISC CPU using Cu interconnects with 6.4 M transistors in a 40 mm2 area, which is fully functional. They are on track for full scale manufacturing. This theme was carried over in the talk by R. Venkataraman of Motorola describing their efforts in integrating multilevel copper metallization into a high performance sub-0.25 um technology. He also discussed barriers for cupper interconnects. Simon Wong from Stanford University also talked about barriers for copper interconnects and covered various examples such as Ti/TiN, TiW, Ta, and TaN. An ideal barrier would have to fulfill several rerquirements including adhesion, good barrier to diffusion, chemical-mechanical-polishing compatibility, low contact resistance etc. Wong mentioned that no barrier currently fulfills all these requirements and multilayer systems would probably be needed.

The symposia that comprise the Spring Meeting represent a varied selection from Materials Science Research areas, that are inherently interdisciplinary. An example is Symposium CC, Biomaterials regulating cell function and tissue development, representing the rising interest in and importance of Biomaterials. An interesting talk was given by Janet Hardin-Young regarding development of cultured skin. She described the development of Apligraf(TM) which is a human skin equivalent (HSE). The HSE consists of a collagen lattice containing dermal fibroblasts overlaid with an epidermal layer. This artificial skin has been used for healing a wound. In additon, pigmented living skin equivalents were also developed and tested. The HSE represents a complex tissue engineered construct, which is a living tissue capable of responding to environmental signals. It is also a useful model to answer basic scientific questions.

Symposium X, Frontiers of Materials Research, has traditionally been used to present invited reviews of important topics specifically aimed at non-specialists. This Meeting's focus is "Historical themes in semiconductor materials and devices." The first talk was presented by Martin Klein of Yale University "Einstein, quanta and the beginnings of materials science" tracing the beginnings of basic materials science and materials physics, starting with Newton. The second talk on "The complex foundations of silicon electronics" traced the historical background of the current silicon revolution in electronics. The talks constituted a good beginning to the theme of silicon electronics.

As the use of photonic materials proliferates, reliability of such devices--base components, hybrid integration, and packaging--has become an issue. A series of invited papers today in Symposium DD examined materials reliability issues associated with waveguides, packaged devices, wiring, optical fibers, and other components of photonic systems. While the active Er-doped silica has relatively few reliability problems, problems with the pump laser still persist. Also, light guide fibers suffer from several problems such as defects and other variations along their length causing strength to drop precipitously and water and stress effects on surfaces to cause further strength losses. Another issue is how to maintain the endface geometry of optical connector ferrules; the silica fiber in the ceramic ferrule can lose connectivity with its mating fiber due to physical instability based on expansion coefficient mismatch, and different chemical and physical properties that express themselves during polishing of the mating surfaces.

Graduate Student award finalists

Graduate Student Award Winners

Hao Lee, University of Oregon, Eugene, OR, "Effect of In-Situ Annealing on the Microstructure and Optical Properties of Self-Organized InAs/GaAs Quantum Dots Grown By Molecular Beam Epitaxy"

Yunfeng Lu, University of New Mexico, Albuquerque, NM, "Surfactant Templated Porous Hybrid Organic/Inorganic Thin Films"

George B. Palmer, Northwestern University, Evanston, IL, "Systematic Study of Transparent Conductors in the Gallium-Indium Tin-Zinc Oxide System"

Mihail N. Popescu, Emory University, Atlanta, GA, "Self-Consistent Rate Equation Approach To Transitions in Critical Island Size in Metal (100) and Metal (111) Homoepitaxy"

Jay J. Senkevich, Virginia Tech, Blacksburg, VA, "Optical Methods to Determine Morphological Changes in Low-k Thin Film Polymers"

Carlo Waldfried, University of Nebraska, Lincoln, NE, "The Growth Mode and Electronic Structure of Strained Thin Films of Gadolinium"