Nanostructured c-Si surfaces obtained by sequential ion implantation of C+ and Ti+: Tribophysical and structural characterization

Abstract

The effect of the sequential implantation of C+ and Ti+ ions on the microstructure and tribophysical properties of smooth crystalline silicon surfaces (c-Si) is evaluated. Microstructural characterization of the samples was performed by scanning electron microscopy, grazing incidence X-ray diffraction and by Rutherford backscattering spectrometry. The surface free energies of the implanted surfaces were also determined and their nanotribological response was evaluated by atomic force microscopy (AFM). It is shown that the sequential implantation of these ions, followed by annealing treatments at proper temperatures, results in thin modified nanolayer formed by a dense dispersion of SiC and TiSi2 nanoparticles in a recrystallized Si matrix that leads to a decrease of the surface energy of the samples, with enhanced nanowear response. These results strongly suggest that this approach can be used to improve the surface properties of Si wafers enlarging its application performance, namely in what concerns NEMS and MEMS devices.