A INTRODUCTION

Recent progress in the experimental investigation of SiC surfaces has reflected the increasing availability of high quality single crystals and the development of methods for obtaining clean ordered surfaces in ultra-high vacuum (UHV). During the last few years a number of distinct surface phases have been identified and characterized. The origins and properties of these surface phases increasingly have been subjected to theoretical investigation. While the picture is very far from complete, at the present time a quantitative understanding of several intrinsic SiC surface reconstructions is within reach, and other reconstructions have received detailed experimental examination. In addition, there has been considerable work on the related subject of metallization of well-characterized surfaces. The aim of this Datareview is to organize and describe the current status of research on the atomic scale structure and composition of crystalline SiC surfaces and the evolution and properties of such surfaces following metallization. As discussed elsewhere in this volume, SiC exhibits well over 100 structural polytypes. Virtually all of the reported research on crystalline surfaces has involved ? (cubic) or ?(6H) (hexagonal) polytypes, since these are the most readily available in a form suitable for characterization. Investigation of the properties of concern - surface structure, composition and reactivity on an atomic scale - requires a UHV environment and a variety of electron, optical and ion spectroscopies and other techniques.

A brief enumeration of the relevant UHV...