| The purpose of this book is to provide the theoretical and practical background necessary to the study of single-crystal materials by means of high resolution Xray diffractometry and topography. Whilst some of these techniques have been available for over fifty years, and the basic theory for even longer, it is in the last decade that they have grown enormously in importance, essentially for two technological reasons. On the one hand there has been the development of the powerful sources for scientific and industrial research: dedicated electron storage rings for synchrotron radiation, which have enabled the ideas and techniques developed in the earlier years to be applied and extended. On the other hand has been the industrial need for characterisation and control of the high-quality crystals that now form the heart of so many of the devices used for the electronics, communications and information engineering industries: integrated circuits, sensors, optoelectronic and electroacoustic devices and microprocessors. Techniques such as high resolution X-ray diffractometry, that for half a century were rather obscure research tools, are now in daily use for industrial quality control.
Educational establishments have not yet fully responded to this growth, and the availability of trained ‘characterisation’ scientists and engineers is a limiting factor in many industries that manufacture devices based upon high-quality crystals. In consequence, many research or quality control laboratories are staffed by people trained in different fields, who may be unaware of both the potentialities and the pitfalls of the X-ray techniques. In this book we attempt to redress these problems. We assume only a knowledge of the materials structures and defects whose characterisation is required. We provide the elementary and advanced theory of X-ray diffraction that is required to utilise the techniques; besides covering the mathematical formalism we have taken pains to present the conclusions of the theory qualitatively and visually, to make its consequences more accessible. We discuss in depth the techniques of X-ray diffractometry and topography, including both the practical details and the application of the theory in the interpretation of the data. The limits of the techniques are explored throughout, an attitude that takes particular technological importance in the light of the present concern with very thin films and surf ace layers. |
