The last few years have ~een rapid improvements in semiconductor growth techniques which have produced an expanding range of high quality heterostructures for new semiconductor devises. As the dimensions of such structures approach the nanometer level, it becomes increasingly important to characterise materials properties such as composition uniformity, strain, interface sharpness and roughness and the nature of defects, as well as their influence on electrical and optical properties. Much of this information is being obtained by electron microscopy and this is also an area of rapid progress. There have been advances for thin film studies across a wide range of techniques, including, for example, convergent beam electron diffraction, X-ray and electron energy loss microanalysis and high spatial resolution cathodoluminescence as well as by conventional and high resolution methods. Important develop ments have also occurred in the study of surfaces and film growth phenomena by both microscopy and diffraction techniques. With these developments in mind, an application was made to the NATO Science Committee in late summer 1987 to fund an Advanced Research Work shop to review the electron microscopy of advanced semiconductors. This was subsequently accepted for the 1988 programme and became the "NATO Advanced Research Workshop on the Evaluation of Advanced Semiconductor Materials by Electron Microscopy". The Workshop took place in the pleasant and intimate surroundings of Wills Hall, Bristol, UK, during the week 11-17 September 1988 and was attended by fifty-five participants from fourteen countries.

The first symposium on electron microscopy and materials for ultra-large scale integration (ULSI) at the Society's meeting attracted 34 papers by contributors from Asia, North America, and Europe. They cover specimen preparation and defect analysis in semiconductor devices; metallization, silicides, and diffusion barriers; the advanced characterization of ULSI structures, and semiconductor epitaxy and heterostructures. Annotation copyrighted by Book News, Inc., Portland, OR

The Advanced Study Institute provided an opportunity for researchers in universities, industry and National and International Laboratories, from the disciplines ofmaterials science, physics, chemistry and engineering to meet together in an assessment of the impact of electron and scanning probe microscopy on advanced material research. Since these researchers have traditionally relied upon different approaches, due to their different scientific background, to advanced materials problem solving, presentations and discussion within the Institute sessions were initially devoted to developing a set ofmutually understood basic concepts, inherently related to different techniques ofcharacterization by microscopy and spectroscopy. Particular importance was placed on Electron Energy Loss Spectroscopy (EELS), Scanning Probe Microscopy (SPM), High Resolution Transmission and Scanning Electron Microscopy (HRTEM, HRSTEM) and Environmental Scanning Electron Microscopy (ESEM). It was recognized that the electronic structure derived directly from EELS analysis as well as from atomic positions in HRTEM or High Angle Annular Dark Field STEM can be used to understand the macroscopic behaviour of materials. The emphasis, however, was upon the analysis of the electronic band structure of grain boundaries, fundamental for the understanding of macroscopic quantities such as strength, cohesion, plasticity, etc.

This volume expands and updates the coverage in the authors' popular 1992 book, Electron Microdiffraction. As the title implies, the focus of the book has changed from electron microdiffraction and convergent beam electron diffraction to all forms of advanced transmission electron microscopy. Special attention is given to electron diffraction and imaging, including high-resolution TEM and STEM imaging, and the application of these methods to crystals, their defects, and nanostructures. The authoritative text summarizes and develops most of the useful knowledge which has been gained over the years from the study of the multiple electron scattering problem, the recent development of aberration correctors and their applications to materials structure characterization, as well as the authors' extensive teaching experience in these areas. Advanced Transmission Electron Microscopy: Imaging and Diffraction in Nanoscience is ideal for use as an advanced undergraduate or graduate level text in support of course materials in Materials Science, Physics or Chemistry departments.

This issue of ECS Transactions focuses on issues pertinent to development of wide-bandgap semiconductor materials and devices, encompassing inorganic wide-bandgap semiconductors: III-nitrides (e. g. gallium nitride), II-oxides, SiC, diamond, II-VI, and also emerging materials such as organic-inorganic nanoscale structures.