Monte Carlo (MC) simulations are a powerful tool for the analysis of ion-solid interactions. The MC code McChasy (Monte Carlo CHAnneling SYmulation) allows the evaluation of Rutherford Backscattering Spectrometry spectra in the Channeling mode to quantify implantation damage. The code works on common personal computers and takes into account randomly displaced atoms as well as certain types of extended defects. In this paper, we report recent improvements of the McChasy code, including a unique approach to the calculation of impact parameters between ions and target atoms in three dimensions (along with computing thermal vibrations also in three dimensions). Furthermore, the use of a rotation matrix to provide different orientations of dislocation lines and an updated model of edge dislocations were also implemented in the code. Dislocation parameters are obtained directly from high-resolution Transmission Electron Microscopy micrographs. Two case studies are presented to highlight the importance of these improvements: Ni-implanted Al was analyzed as an example of a crystal mainly containing dislocations; Er-implanted ZnO was studied, revealing the strength of MC analysis for materials containing a mixture of different defect types, namely, randomly displaced atoms and dislocations.

In this paper, we present the detailed study of optical and structural properties of Yb implanted single ZnO crystals. Hydrothermally grown wurtzite (0001) ZnO crystals were implanted with 150 keV Yb ions to fluencies of 5 × 10¹⁴ and 1 × 10¹⁵ at/cm². After ion implantation, two different types of annealing were performed: rapid thermal annealing (RTA) and millisecond range flash lamp annealing (FLA). Crystalline quality, damage recovery, and Yb lattice site location were evaluated by the Channeling Rutherford Backscattering Spectrometry (RBS/c). It is shown that independent of the used annealing technique, defects formed in ZnO during ion implantation can be removed. Upon RTA performed at the temperature higher than 800 °C, strong out-diffusion of implanted Yb atoms and precipitation on the surface takes place. Consequently, the degradation of the photoluminescence (PL) efficiency is observed. The diffusion of implanted Yb during millisecond range FLA does not occur for such experimental conditions. Moreover, FLA treatment for 20 ms leads to the formation of single crystalline ZnO layer with Yb incorporated in the substitutional lattice sites. According to RBS/c and PL data, Yb atoms substituted in the Zn sublattice are predominantly in the 2+ oxidation state. The most intensive PL has been observed after annealing at 800 °C for 20 min which is accompanied with the reduction of Yb substitutional fraction and formation of octahedron Yb-oxygen clusters within ZnO.