The 1998 MRS Spring Meeting continued to gather momentum it entered the third day of sessions. Along with oral presentations, the exhibit, the evening posters as well as one tutorial kept attendees very busy. Symposium D held a tutorial - Defects/impurities and Gettering in silicon science and technology.

Once again Symposium X had two interesting talks at lunch time. The first on "Materials needs for semiconductors" by Jane Shaw touched upon several materials science aspects of Semiconductors. Shaw described the evolution of semiconductors and transistors including the increease in the number of interconnect layers, number of transistors and the clock frequency. She talked about requirements for polymers, optical lithography and photoresist properties. She also briefly described the continually decreasing width of interconnects. She suggested that understanding molecular architecture/polymers properties as well as continual innovation in materials is crucial for future developments of ICs. The second symposium X talk was given by Junji Kido of Yamagata University talking about Organic electroluminescent devices (OLEDs). He started by mentioning that nature is the most efficient architect of organic luminescence as demonstrated in fireflies. He also made the point that while the blue LED (using III nitrides) has received a lot of press, blue light using electroluminescence was available 30 years ago. The advantages of organic EL devices include large areas, low driving voltages, fast response, high brightness and colors. He demonstrated EL displays as part of his presentation including a 9 in display. These displays can be used for various applications including full color displays, displays in car radios etc. This technology clearly holds great potential.

Symposia B and C held a joint session on field emission cathodes and displays including three invited talks "Darpa high definition systems program" by Bruce Gnade (DARPA), "Field emission cathode performance in thin CRTs" by Chris Spindt et al. (Candescent Technologies) and "Development of field emission flat panel displays" by Alec Talin (Motorola). In the third talk, the development of a field emission display at Motorola was described in some detail. Talin showed a video of the display showing its clarity as well as visibility even from steep angles. Talin indicated that field emission displays (FEDs) are better than CRTs, LCDs, plasmas or EL displays due to various reasons including lower manufacturing costs. The Motorola FED displays use Spindt arrays as cathodes which yield a very stable performance after some initial degradation. Talin made the point that future development FEDs would depend on lowering manufacturing costs including eliminating sub micron lithography, minimizing interelectrode spacing and reducing the need for clean rooms. Mention was also made of nanocoralline C-N film which is coral-like carbon film with dendritic morphology of nanocrystalline carbon. Motorola appears to be ready to bring these displays to commercialization as soon as feasible.

In the Symposium A session on solar cells, Subhendu Guha (United Solar Systems Corp) talked about materials issues in the commercialization of amorphous silicon thin-film photovoltaic technology. In 1997, a record stable cell efficiency of 13% was achieved. However for greater usage of solar cells, the cost per watt (currently $4.50 /watt) must be lowered. In addition, the questions of aethetics, flexibility and ruggedness must all be addressed. Guha described various architectures and suggested that a triple junction multibandgap structure offers the best promise of improved efficiency. Guha also emphasized the fact that the distinction between amorphous silicon and nanocrystalline silicon for use in solar cell applications is dissappearing.

Symposium O, Hybrid Materials, included a very interesting talk on "Hybrid Materials: Intricate structures guiding complex dynamics" by Patrick Judeinstein (Laboratoire de Chemie Structurale Organique, Orsay, France). Judeinstein described silica polymer structures including SiO2/PEG polymers and various characterization techniques. His presentation discussed two types of such hybrids, type I where the two components are mixed together, and type II wherein grafting of components is involved. Hybrids very much depend on the synergy between the organic and inorganic components. Within this symposium O, another talk on "Enzyme encapsulation within sol-gel glasses" by J. Livage (University of Paris) highlighted the range of topics discussed. Sol-gel chemistry was used to entrap biomolecules within silica matrices. While their biochemical activity is retained, the sol-gel structure prevents leaching and the pores within the xerogel allow small molecules to diffuse through for reaction with the trapped enzymes. Examples of applications described included biosensors using glucose oxidase (GOD) - silica films for measuring amount of converted glucose, and entrapment of bacteria within silica matrices for use as enzyme reservoirs for use as bioreactors.

Paul Holloway of the University of Florida talked about "Advances in thin film cathodoluminescent phosphors" in Symposium B. Thin film phosphors offer several advantages over powder phosphors including controlled resolution, slower degradation, thermal properties and contamination. Pulsed laser deposition of Y2O3 doped with Europium was achieved. Good brightness including high efficiency was achieved by controlling microstructure of the oxide.

Three poster awards were presented on this second day of poster sessions. The awards went to :

H8.6 "A two-step low temperature process for a p-n junction formation due to hydrogen enhanced thermal donor formationin p-type Czochralski silicon," Reinhart Job, Wolfgang Fahrner (Univ of Hagen, Germany), Alexander Ulyashin (Belarussian State Polytechnical Academy, Minsk).

L9.3 "In-plane anisotropy of giant magnetoresistance in Co/Cu multilayers electrodeposited on Si(001) substrates," Matsuhiro Shima, L. G. Salamanca-Riba (Univ of Maryland), T. P. Moffat, R. D. McMichael, L. J. Swartzendruber (NIST).

O8.8 "Reaction engineering approach to bicomponent alkoxysilane co-condensation," Stephen Ranking, A. V. McCormick (Univ of Minnesota).