Applications and Future Directions

Abstract

Chapters 6, 7, and 9 ilnclude many examples of using the reflection high-electron energy diffraction (RHEED) pole figure technique for film-texture analysis. Since electrons interact strongly with matter, RHEED is most suitable for the study of texture when there is a limited amount of sample material. This is the case at the initial stages of the growth of films, where only a small volume of deposits is condensed on the substrate. X-rays interact weakly with matter, but if the source intensity is strong, such as that from a synchrotron radiation source, x-ray diffraction can achieve the same goals. However, RHEED is more accessible in an individual laboratory setting, and it is a less expensive tool to build. Another advantage of RHEED is that it is surface sensitive and has a limited penetration depth. Therefore, it is suitable for studying growth-front texture without interference from the bulk of the film. The diffraction data obtained from x-rays, on the other hand, inevitably includes information from the bulk of the film (and the substrate) because x-rays have such a large penetration depth. In this sense, RHEED is rather unique for the study of texture at the growth front. In this chapter, we will give some examples of using the RHEED pole figure technique to study the evolution of growth-front texture. We will also comment on possible instrumental improvements that could be made to RHEED pole figure equipment.