INVESTIGATING THE DEFORMATION FIELDS IN A MIRROR CRYSTAL OF AN X- RAY INTERFEROMETER UNDERGONE IONIC IMPLANTATION

Abstract

The review of scientific literature on the theory of the X-ray interference shows that many investigations have been devoted to the issues on the thin implanted layers by X-ray diffraction methods. All these studies have certain common characteristic features. In particular, all X-ray topographic investigations have been carried out with samples radiated by powers higher than MeV.

At radiating with ions of low powers, especially in small doses, it is necessary to apply X-ray interferometric methods whose sensitivity and resolution are incomparably large. In the present work, the results of theoretical and experimental X-ray interferometric investigations of the crystal defects, arising as a result of ionic implantation by small doses and low powers are introduced.

The investigation results are presented by X-ray diffraction moiré patterns of the deformation fields, arising in one of the operating parts of the mirror block of a three –crystal X-ray silicon interferometer subjected to ionic implantation, depending on the radiation dose. The stress redistribution, occurring in that section of the interferometer block at its bombardment is also studied. The results obtained are a basis for solving the inverse problem, namely, the problem of restoring the fields of mechanical stresses in the crystal blocks of the interferometer by interpreting the moiré patterns, as the change in the moiré patterns will include information on mechanical stresses. Thus, the method of the X-ray interferometric moiré allows to carry out a direct experimental investigation of the fields of mechanical stresses created by structural defects of the crystal lattice. The condition for the applicability of the expression for determining the period of the moiré patterns at estimating the intracrystal deformations is obtained.