Raman scattering studies of low energy Ar⁺ ion implanted monocrystalline silicon for synchrotron applications

The surface and subsurface of the Ar⁺ ion implanted monocrystalline silicon was modified due to the exchange of energy and momentum of ions. This procedure is necessary for shape homogeneity of monocrystalline silicon surface useful in synchrotron application. The implantation has modified the vibrational modes of monocrystalline silicon investigated by Raman spectroscopy using polarized and unpolarized inelastically scattered light. An additional pronounced shift of peak position and broadening of the linewidth of optical phonon mode at lower frequency was observed in Ar⁺ ion implanted monocrystalline silicon. The shift and broadening of such peak was originated from the amorphous and nanocrystalline silicon. The maximum depth of such transformation was equal to the depth of Ar⁺ ion implantation with energies of 400 eV which was about 2 nm studied by ion profiling method. This was also confirmed by maximum depth of penetration of ultraviolet laser in monocrystalline silicon.