Electron Microscopic Studies of Single-Crystal Silicon after Irradiation with Low-Energy Xenon Ions

In modern nanotechnologies, the effective use of ion beams requires studies of the interaction of accelerated ions with atoms of irradiated materials. The state of surface regions subjected to ion impact during the creation and modification of various structures has a significant effect on their characteristics; therefore, data on the distribution of implanted beam ions in the sample and their influence on the structure of the amorphized material are of great importance. In this work, using the methods of scanning transmission electron microscopy and energy-dispersive X-ray microanalysis, samples of cross-sectional single-crystal silicon substrates irradiated with xenon ions with an energy of 5 and 8 keV and a dose of about 1016 cm—2 are studied. Clusters formed by implanted xenon atoms in an amorphized silicon layer are revealed in images and maps of the distribution of chemical elements. Micrographs of a cross-sectional sample of a substrate bombarded with 8-keV ions are obtained and processed. The geometric parameters of the xenon clusters are determined, the modal size of which is 1.5 nm. Additional studies of the prepared thin foil with a planar cross section are carried out using the electron diffraction method. A comparison is made between the experimentally obtained concentration profiles of implanted xenon atoms and the results of computer simulations using the Monte Carlo method via different mechanisms of the degassing of implanted atoms. The experimentally established and calculated values of the peak concentration of xenon are in good agreement and amount to about 5 at %.