High precision structural measurements on thin epitaxial layers by means of ion-channeling

The possibility of obtaining a detailed description of the crystalline structure of single-crystal samples is intrinsic to several applications of the ion-channeling technique. This paper reports a new approach to the use of channeling measurements which allows a precise characterization of the crystallography of very thin crystalline layers. The use of a precise mathematical description of the sample rotations which are involved in a typical channeling experiment gives the possibility of having a direct correlation between the sample lattice structure and the angular coordinates where the axial and planar channeling minima are located. The model is fully tested and the precision of the measurements obtained by this technique is compared to the results of double crystal X-ray diffraction measurements on the same systems. This technique is particularly well adapted to the measurement of lattice strain in heteroepitaxial structures. © 1990.