The first international symposium on the subject "The Physics and Chemistry of Si02 and the Si-Si02 Interface," organized in association with the Electrochemical Society, Inc. , was held in Atlanta, Georgia on May 15- 20, 1988. This symposium contained sixty papers and was so successful that the sponsoring divisions decided to schedule it on a regular basis every four years. Thus, the second symposium on "The Physics and Chemistry of Si02 and the Si02 Interface was held May 18-21, 1992 in St. Louis, Missouri, again sponsored by the Electronics and Dielectrics Science and Technology Divisions of The Electrochemical Society. This volume contains manuscripts of most of the fifty nine papers presented at the 1992 symposium, and is divided into eight chapters - approximating the organization of the symposium. Each chapter is preceded with an introduction by the session organizers. It is appropriate to provide a general assessment of the current status and understanding of the physics and chemistry of Si02 and the Si02 interface before proceeding with a brief overview of the individual chapters. Semiconductor devices have continued to scale down in both horizontal and vertical dimensions. This has resulted in thinner gate and field oxides as well as much closer spacing of individual device features. As a result, surface condition, native oxide composition, and cleaning and impurity effects now provide a much more significant contribution to the properties of oxides and their interfaces.

The properties of Si02 and the Si-Si02 interface provide the key foundation onto which the majority of semiconductor device technology has been built Their study has consumed countless hours of many hundreds of investigators over the years, not only in the field of semiconductor devices but also in ceramics, materials science, metallurgy, geology, and mineralogy, to name a few. These groups seldom have contact with each other even though they often investigate quite similar aspects of the Si02 system. Desiring to facilitate an interaction between these groups we set out to organize a symposium on the Physics and Chemistry of Si()z and the Si-Si()z Interface under the auspices of The Electrochemical Society, which represents a number of the appropriate groups. This symposium was held at the 173rd Meeting of The Electrochemical Society in Atlanta, Georgia, May 15-20, 1988. These dates nearly coincided with the ten year anniversary of the "International Topical Conference on the Physics of Si02 and its Interfaces" held at mM in 1978. We have modeled the present symposium after the 1978 conference as well as its follow on at North Carolina State in 1980. Of course, much progress has been made in that ten years and the symposium has given us the opportunity to take a multidisciplinary look at that progress.

This issue of ECS Transactions places a focus on ultrathin gate dielectrics: novel technologies, characterization methods, process modeling, fundamental limits, and projections for scaling the gate oxide thickness.

An extrapolation of ULSI scaling trends indicates that minimum feature sizes below 0.1 mu and gate thicknesses of Audience: Both expert scientists and engineers who wish to keep up with cutting edge research, and new students who wish to learn more about the exciting basic research issues relevant to next-generation device technology.