Thin layer diffraction

Many of the challenges in X-ray diffraction arise from the requirement to produce detailed information on very thin layers. This paper illustrates the present limits in the analysis of X-ray diffraction profiles with examples of epitaxial and polycrystalline layers. One of the primary uses of X-ray diffraction of epitaxial layers is in the determination of composition and thickness, but this can be fraught with problems for the unwary yet a very powerful technique when the correct procedures are used. Often the assumptions concerning epitaxial quality are rather ambitious and this paper will consider the influence of imperfect epitaxy on the subsequent interpretation. The latter part of this paper will discuss the limits in polycrystalline diffraction analysis for the study of nano-structures and the initial stages of the recrystallisation of amorphous Si.